Posts Tagged treadmill
Background and Objectives: High-intensity interval training (HIIT) is a promising strategy for improving gait and fitness after stroke, but optimal parameters remain unknown. We tested the effects of short vs long interval type and over-ground vs treadmill mode on training intensity.
Methods: Using a repeated measures design, 10 participants with chronic hemiparesis performed 12 HIIT sessions over 4 weeks, alternating between short and long-interval HIIT sessions. Both protocols included 10 minutes of over-ground HIIT, 20 minutes of treadmill HIIT and another 10 minutes over-ground. Short-interval HIIT involved 30 second bursts at maximum safe speed and 30-60 second rest periods. Long-interval HIIT involved 4-minute bursts at ~90% of peak heart rate (HRpeak) and 3-minute recovery periods at ~70% HRpeak.
Results: Compared with long-interval HIIT, short-interval HIIT had significantly faster mean overground speeds (0.75 vs 0.67 m/s) and treadmill speeds (0.90 vs 0.51 m/s), with similar mean treadmill HR (82.9 vs 81.8%HRpeak) and session perceived exertion (16.3 vs 16.3), but lower overground HR (78.4 vs 81.1%HRpeak) and session step counts (1481 vs 1672). For short-interval HIIT, training speeds and HR were significantly higher on the treadmill vs. overground. For long-interval HIIT, the treadmill elicited HR similar to overground training at significantly slower speeds.
Conclusions: Both short and long-interval HIIT elicit high intensities but emphasize different dosing parameters. From these preliminary findings and previous studies, we hypothesize that overground and treadmill short-interval HIIT could be optimal for improving gait speed and overground long-interval HIIT could be optimal for improving gait endurance.
[ARTICLE] Effects of bodyweight support and guidance force on muscle activation during Locomat walking in people with stroke: a cross-sectional study – Full Text
Locomat is a robotic exoskeleton providing guidance force and bodyweight support to facilitate intensive walking training for people with stroke. Although the Locomat has been reported to be effective in improving walking performance, the effects of training parameters on the neuromuscular control remain unclear. This study aimed to compare the muscle activities between Locomat walking and treadmill walking at a normal speed, as well as to investigate the effects of varying bodyweight support and guidance force on muscle activation patterns during Locomat walking in people with stroke.
A cross-sectional study design was employed. Participants first performed an unrestrained walking on a treadmill and then walked in the Locomat with different levels of bodyweight support (30% or 50%) and guidance force (40% or 70%) at the same speed (1.2 m/s). Surface electromyography (sEMG) of seven muscles of the affected leg was recorded. The sEMG envelope was time-normalised and averaged over gait cycles. Mean sEMG amplitude was then calculated by normalising the sEMG amplitude with respect to the peak amplitude during treadmill walking for statistical analysis. A series of Non-parametric test and post hoc analysis were performed with a significance level of 0.05.
Fourteen participants with stroke were recruited at the Yangzhi Affiliated Rehabilitation Hospital of Tongji University (female n = 1; mean age 46.1 ± 11.1 years). Only the mean sEMG amplitude of vastus medialis oblique during Locomat walking (50% bodyweight support and 70% guidance force) was significantly lower than that during treadmill walking. Reducing both bodyweight and guidance increased muscle activity of gluteus medius and tibialis anterior. Activity of vastus medialis oblique muscle increased as bodyweight support reduced, while that of rectus femoris increased as guidance force decreased.
The effects of Locomat on reducing muscle activity in people with stroke were minimized when walking at a normal speed. Reducing bodyweight support and guidance force increased the activity of specific muscles during Locomat walking. Effects of bodyweight support, guidance force and speed should be taken into account when developing individualized Locomat training protocols for clients with stroke.
Gait disturbance is one of the major consequences associated with stroke. Due to the impaired supraspinal control, the gait pattern post stroke is characterized as muscle weakness, spasticity, abnormal muscular amplitude and asymmetrical temporal ordering of muscle activity [1, 2]. Impaired walking ability not only reduces the functional independency of stroke survivors, but also increases a series of risks, like fall [3,4,5]. The restoration of functional walking ability requires intensive training with a symmetrical gait pattern [6,7,8].
Various robot-assisted gait trainers, like Locomat, G-EO system Evolution and Gait Trainer, have been designed and implemented in gait rehabilitation for stroke patients [9,10,11,12,13,14,15]. These gait trainers enable a repetitive walking training with predefined normal gait pattern and largely reduce the physical demand of therapists . Those robot-assisted gait trainers, like Locomat (Hocoma, Switzerland), can provide a range of adjustable functions, including bodyweight support (BWS), guidance force (GF) and walking speed, allowing clinicians to develop an individualised training protocol that best fits patient’s ability level [17, 18]. Locomat training, however, has been found to reduce muscle activities in both healthy individuals and people with stroke when compared to overground walking [19, 20]. For example, Coenen and colleagues  found that the application of BWS and GF significantly reduced activities of several muscles of affected leg in people with stroke. This feature of Locomat training is considered as a negative aspect of its clinical implication because voluntary contraction of muscles plays a key role in motor relearning . In addition, the exoskeletons of Locomat limit the movement in sagittal plane and reduce the degree of freedom of pelvis which may lead to abnormal interaction between the leg and exoskeleton as well as abnormal muscle activity pattern [10, 22].
There is sufficient evidence showing that the Locomat training provided better improvement in terms of independent walking ability, walking speed, balance and disability than conventional physiotherapy to people with stroke [23,24,25,26,27,28]. There is also evidence that Locomat training significantly improved the duration of single stance phase, step length ratio on the paretic leg when walking on the ground [29, 30]. However, there are also studies showing that the Locomat was not superior to conventional therapy in people with stroke [9, 30, 31]. Despite the heterogeneous features of participants, the difference in training parameters of Locomat may also contribute to the controversial results. In healthy participants, there is ample evidence that BWS or GF can affect the activation of specific muscles [10, 19, 20, 32, 33]. There are also studies reporting significant interactions between BWS, GF and walking speed on voluntary control indicating that the mechanisms of those parameters are complex . In a recent study, however, researchers reported that varying BWS and GF was not associated with changes of muscle activity in people with stroke, whereas increasing walk speed led to greater muscle activity . Since the walking speeds used in previous studies were relatively low (0.56 m/s and 0.61 m/s respectively) [19, 20] and the increase of speed was associated with greater muscle activity [32, 35], it is of interest to investigate whether a higher walking speed would modulate the difference in muscle activity between Locomat walking and treadmill walking.
To further investigate the effects of BWS and GF on active muscle activity, this study aimed to compare the muscle activity level of affected leg between Locomat and treadmill walking at a normal speed in people with stroke. This study also investigated the effects of varying BWS and GF on muscle activity patterns during Locomat walking. Therefore, we hypothesized that when walking at a normal speed, people with stroke exhibit lower muscle activity in the affected leg during Locomat walking than during unrestrained treadmill walking. We also hypothesized that reducing BWS and GF will increase muscle activity level of the affected leg in people with stroke.
Continue —> Effects of bodyweight support and guidance force on muscle activation during Locomat walking in people with stroke: a cross-sectional study | Journal of NeuroEngineering and Rehabilitation | Full Text
[ARTICLE] Walking with head-mounted virtual and augmented reality devices: Effects on position control and gait biomechanics – Full Text
What was once a science fiction fantasy, virtual reality (VR) technology has evolved and come a long way. Together with augmented reality (AR) technology, these simulations of an alternative environment have been incorporated into rehabilitation treatments. The introduction of head-mounted displays has made VR/AR devices more intuitive and compact, and no longer limited to upper-limb rehabilitation. However, there is still limited evidence supporting the use of VR and AR technology during locomotion, especially regarding the safety and efficacy relating to walking biomechanics. Therefore, the objective of this study is to explore the limitations of such technology through gait analysis. In this study, thirteen participants walked on a treadmill in normal, virtual and augmented versions of the laboratory environment. A series of spatiotemporal parameters and lower-limb joint angles were compared between conditions. The center of pressure (CoP) ellipse area (95% confidence ellipse) was significantly different between conditions (p = 0.002). Pairwise comparisons indicated a significantly greater CoP ellipse area for both the AR (p = 0.002) and VR (p = 0.005) conditions when compared to the normal laboratory condition. Furthermore, there was a significant difference in stride length (p<0.001) and cadence (p<0.001) between conditions. No statistically significant difference was found in the hip, knee and ankle joint kinematics between the three conditions (p>0.082), except for maximum ankle plantarflexion (p = 0.001). These differences in CoP ellipse area indicate that users of head-mounted VR/AR devices had difficulty maintaining a stable position on the treadmill. Also, differences in the gait parameters suggest that users walked with an unusual gait pattern which could potentially affect the effectiveness of gait rehabilitation treatments. Based on these results, position guidance in the form of feedback and the use of specialized treadmills should be considered when using head-mounted VR/AR devices.
Over the past two decades, the application of virtual reality (VR) technology in a healthcare setting has become increasingly popular. It has been incorporated into clinical practices such as in the rehabilitation of stroke survivors, as well as patients with cerebral palsy and multiple sclerosis [1–3]. There is ample evidence suggesting that VR-based rehabilitation facilitates upper limb motion  and dynamic balance  among stroke survivors. More recently, research groups have also investigated the use of VR in dynamic situations (i.e. treadmill walking), aiming to improve balance and facilitate gait recovery [6–9].
In current clinical practice, gait retraining often includes treadmill training under the supervision of practitioners or through provision of real-time biofeedback. It is a widely adopted technique that aims to permanently correct faulty gait patterns and has been found to be effective in both walking and running gait modifications [10–12]. For example, a recently published randomized controlled trial showed that gait retraining was an effective intervention for reduction of knee loading and also improved symptoms among patients with early knee osteoarthritis . Incorporation of VR technology into conventional gait retraining has the potential to further enhance training outcomes. VR allows users to actively interact with a simulated environment in real-time and offers the opportunity to practice skills acquired in the virtual environments to everyday life . VR-based gait retraining has the potential to facilitate implicit learning, enhance variety, and actively engage the patient during training. These attributes are crucial in the optimization of motor learning and could maximize the training effect .
Walking is normally an automatic process. It has been suggested that conscious modification to walking patterns could affect gait retraining adaptations . A previous study found that subjects who trained with distraction were able to retain the training effect longer than the group who focused on correction . VR-based retraining could include different tasks and games while the patients modify their gait pattern as it could help patients to maintain focus and promote implicit motor learning. Moreover, the training environment, feedback type and level of difficulty of tasks can be manipulated within the VR environment relatively effortlessly for the clinician, as compared to conventional gait retraining. Variation in training has been shown to promote a more robust motor pattern and favor adaptation [16,17]. Moreover, motivation and adherence among patients can also be improved with more variation and an adjustable level of difficulty provided in the VR-based training . Stroke survivors were previously found to be more actively engaged in a VR-based training than a conventional task-oriented intervention to improve motor function . The training environment can be designed to simulate real-life activities and include task-specific training and a natural experience can be achieved through immersive VR devices, such as using a head-mounted display (HMD) . Studies have supported task-specific motor skill training with VR in helping to drive neuroplasticity in individuals with progressive neurodegenerative disorder [4,21].
Although multiple studies have reported positive results of gait retraining using VR among various patient groups within the lab [1,5,22,23], there is still little understanding of the limitations and challenges for using VR technology clinically. One overriding concern for using VR technology in clinical applications, especially an HMD, is safety. The user may not be able to recognize his/her own body position when using an immersive VR device, which could result in physical injuries, particularly if the user fails to stay within the boundaries of the treadmill. Suspension devices (i.e. an over-head harness) have been used for protection during VR-based gait rehabilitation , and a recent study showed that both young and older adults were able to use HMD during walking without adverse effects . However, the limit of VR technology on safety was not quantified or discussed. Recent technological advances in both the hardware and software of HMD might allow for safer use. However, there is still a need for evidence-based support and quantifiable data, which could help with practical considerations among VR applications in a clinical setting.
Another concern for gait rehabilitation would be the regularity and quality of gait. Through studying spatiotemporal gait parameters, some studies have reported that walking in a projected VR environment can induce gait instability even in healthy participants [24,25]. Nowadays, VR-based gait retraining using HMD focuses primarily on gait restoration after stroke ; the changes in natural gait due to the use of HMD may not be clinically significant. However, it is crucial for particular patient groups undergoing gait modification to maintain a certain level of regularity in their gait pattern. For instance, knee loading can be affected by spatiotemporal parameters such as cadence and step length  and VR was previously found to alter such parameters in an over-ground setting . The treatment effect of gait retraining in reducing knee loading would likely be affected if the patient’s baseline walking gait was already altered by the use of HMD or other VR devices. The aforementioned studies did not quantify the changes in walking biomechanics when using a HMD, therefore, this study aimed to identify gait parameters that were affected by the use of HMD.
An alternative to VR is Augmented Reality (AR), which does not fully immerse the user in a simulated environment but includes virtual elements that are superimposed on a real-world view . For example, external cues on foot placement could be overlaid on to the walking surface in order to facilitate gait adjustments [28,29]. The addition of feedback in AR-based gait retraining allows for variations in training and could enhance the gait retraining effect. Yet, there is also a lack of understanding of the limitation of using AR devices. Therefore, this study also aimed to examine the biomechanical changes induced by the HMD within an AR setting.
This study was designed to assess whether the use of commercially available HMD in VR and AR settings were suitable for clinical gait retraining. Specifically, the aim was to quantify the limitations of current VR and AR technology based on two practical concerns for clinical applications: 1) safety: the ability of the user to maintain a relatively stable position within the treadmill and 2) natural gait patterns: deviation of walking biomechanics from that of normal-treadmill walking. We hypothesized that there would be variations in the control of body position relative to the treadmill between both VR and AR conditions when compared with normal-treadmill walking. Also, based on altered gait biomechanics reported with the use of HMD in an over-ground setting , we hypothesized there would be variation in the spatiotemporal and joint kinematic measures while walking in VR and AR conditions, when compared with normal-treadmill walking.
Materials and methods
A total of 13 participants (7 females, 6 males; age = 24.6 ± 4.5 years; weight = 63.1 ± 14.5 kg; height = 1.68 ± 0.11 m) were recruited for this study through convenient sampling, which is a comparable sample size to previous studies [30–32]. Participants were free of any musculoskeletal, neurological, neuromuscular or cardiovascular pathology that might hinder walking. The experimental procedures were reviewed and approved by the Departmental Research Committee of the department of Rehabilitation Sciences, The Hong Kong Polytechnic University (Ref.: HSEARS20161018001) and written informed consent was obtained from all participants prior to the experiment.
Participants were asked to walk at a self-selected pace for four minutes to allow for treadmill adaptation prior to data collection . Anthropometric data, including leg length, knee width and ankle width [34–36], were recorded and 39 reflective markers were affixed to specific bony landmarks based on the Vicon Plug-in-Gait® full body model . The marker model was previously established for the measurement of lower-limb kinematics . This study was designed to assess HMD in VR and AR settings using a commercially available model within a typical clinical setting. Thus, the conditions were designed to be simple and without the use of additional lab equipment. All walking trials were conducted on a dual-belt instrumented treadmill (Force-sensing tandem treadmill, AMTI, Watertown, MA, USA; length x width = 1.2 x 0.6 m). Participants wore their own usual shoes and walked under different conditions at 3.0 km/h (0.83 m/s) for three minutes each. The three conditions were Control, VR and AR, details were as follows:
Virtual reality (VR): Immersive 360° panoramic image of the laboratory captured by the Samsung Gear 360 Cam (Samsung, Seoul, South Korea), set up instructions and image file used are provided in the supporting information (S1 File and S1 Fig).
Augmented reality (AR): Real-time display through the rear camera of the HMD, set up instructions are provided in the supporting information (S2 File).
For the AR and VR conditions, participants wore a head-mounted VR device (Samsung Gear VR SM-R322 and Samsung Galaxy S7, Samsung, Seoul, South Korea; width x height x depth: 201.93 x 92.71 x 116.33 mm). The immersive VR/AR environment within this study refers to the panoramic display in a first-person perspective with complete visual obstruction to the real-world environment. The HMD used in this study weighs a total of 470 g, which is comparable to typical commercial HMD models (HTC VIVE Pro: 555 g  and Oculus Rift DK2: 440 g ). Adjustments to the device were made for fit, focus, and orientation for each participant. Participant’s comfort was confirmed through subjective reporting before the beginning of each walking trial.
The test sequence was randomized using a web-based software (www.randomizer.org). To ensure safety, participants were supported by an overhead safety harness providing 0% bodyweight support. The experimental setup is indicated in Fig 1. The individual in Fig 1 of this manuscript has given written informed consent (as outlined in PLOS consent form) to publish the photograph.
Ground reaction force and coordinates of the center of pressure (CoP) were sampled through the instrumented treadmill at 1,000 Hz. Marker trajectories were sampled at 200 Hz using an 8-camera motion capture system (Vicon, Oxford Metrics Group, UK). The instrumented treadmill and motion capture system were synchronized and were set for data collection for three minutes after the treadmill reached the testing speed.[…]
[ARTICLE] The effect of aquatic and treadmill exercise in individuals with chronic stroke – Full Text
We compared the effect of gait training on treadmill versus deep water on balance and gait in 12 ischemic stroke chronic survivors randomly sorted to the Pool or Treadmill Groups. Berg Scale (BBS) and timed up and go test (TUG) were applied before and after the interventions. Just one person applied all tests and she was blinded for the aims of the study. Surface EMG of the paretic and non-paretic (NP) side muscles were recorded during walking on a treadmill. Three 100-ms epochs were extracted from the EMG related to gait phases: weight acceptance; propulsion; and pre-strike. For each epoch, we calculated the RMS of the EMG signal. Participants did gait training for 9 weeks (3 times/week, 40 minutes/session). The Pool group did the deep-water walking with a swimming belt. The Treadmill group walked on the treadmill at the maximum speed they could stand. The Manova group compared the effect of training, group, side, muscles, and gait phase into the EMG. Anova was used to test the effect of training, group side, and gait phase into BBS, TUG and EMG variables. Pool and Treadmill had increased balance and agility. The highest EMG RMS occurred at the paretic side, for the Treadmill and after training. The mm. tibialis anterior, gastrocnemius lateralis, vastus lateralis, and biceps femoris presented the highest RMS for the NP side; while for mm. rectus femoris and semitendinosus, the paretic side presented the highest RMS. Thus, the both types of exercise lead to similar functional adaptations with different muscular activations during walking.
Stroke is the second most common cause of death worldwide and the primary cause of chronic disability in adults1), (2. Without intense rehabilitation during the early days after the stroke, neural injuries gradually develop more pronounced motor impairments due to muscle weakness, spasticity and coordination loss3. Later, stroke survivors with chronic impairment become less independent to perform daily life activities, have less social interaction and are more concerned about their future4. Such dependent person with less social life can be considered as having lost motivation. This deprivation occurs because chronic stroke survivors have small resistance to fatigue4)- (6. They do not feel motivated to move continuously or for long periods since they get easily fatigued; as such, rehabilitation programs for such population should spare their activities between motor rehabilitation and increase in physical fitness in order to increase their resistance to fatigue.
In fact, about 80% of stroke survivors can walk without assistance; but their slow walk constrains their daily life activities7), (8. Walking speed is an important outcome for performance evaluation and for functional evaluation in stroke9), (10. The slow walking is due to the lower limb muscles spasticity11)- (14, muscle weakness, postural imbalance and fear of falling. Those clinical impairments also change the gait biomechanics15), (16, inducing asymmetrical, stereotyped and low ranged compensatory movements17. At the early stage of the rehabilitation program, efforts should be addressed to improve body functions in enhance resistance to fatigue.
The aerobic training applied to stroke people enhances physical ability and improves life independence and quality, reducing morbidity and mortality18. Standard aerobic training is usually developed with walking and running. Treadmill protocols to stroke people can recover impaired gait, improve gait parameters and reduce walking asymmetries19. On the other hand, water walking enhances the afferent sensory inflow and improves peak aerobic capacity and walking endurance, being able to affect gait kinematics in patients with stroke18), (20)- (22. It is not clear whether walking on water would provide the same or more benefits compared with the standard treadmill walking for chronic stroke people. In fact, little information is available to support a rehabilitation program for chronic stroke people with reduced mobility. The aim of this study was to compare the effect of aerobic training treadmill versus aerobic training in water for balance and gait in chronic stroke people. We expect that standard treadmill walking training and water walking training will not have similar biomechanical and functional results; therefore, both types of walking training will lead to similar functional results, but the electrical activity of lower limbs will show different behavior after training. Our first hypothesis is that treadmill gait training and deep-water gait training will lead to similar functional adaptations. Our second hypothesis is that treadmill gait training and deep-water gait training will induce different muscle adaptations that will provide different kinds of muscle activation during the walking test. We believe that training will improve participants’ overall fitness, but training specificity will lead to differing muscle activation during the gait test.[…]
[Abstract] A Preliminary Study of Dual-Task Training Using Virtual Reality: Influence on Walking and Balance in Chronic Poststroke Survivors
Stroke is a leading cause of death and disability in the Western world, and leads to impaired balance and mobility.
To investigate the feasibility of using a Virtual Reality-based dual task of an upper extremity while treadmill walking, to improve gait and functional balance performance of chronic poststroke survivors.
Twenty-two individuals chronic poststroke participated in the study, and were divided into 2 groups (each group performing an 8-session exercise program): 11 participated in dual-task walking (DTW), and the other 11 participated in single-task treadmill walking (TMW). The study was a randomized controlled trial, with assessors blinded to the participants’ allocated group. Measurements were conducted at pretest, post-test, and follow-up. Outcome measures included: the 10-m walking test (10 mW), Timed Up and Go (TUG), the Functional Reach Test (FRT), the Lateral Reach Test Left/Right (LRT-L/R); the Activities-specific Balance Confidence (ABC) scale, and the Berg Balance Scale(BBS).
Improvements were observed in balance variables: BBS, FRT, LRT-L/R, (P < .01) favoring the DTW group; in gait variables: 10 mW time, also favoring the DTW group (P < .05); and the ABC scale (P < .01). No changes for interaction were observed in the TUG.
The results of this study demonstrate the potential of VR-based DTW to improve walking and balance in people after stroke; thus, it is suggested to combine training sessions that require the performance of multiple tasks at the same time.
[ARTICLE] Locomotor skill acquisition in virtual reality shows sustained transfer to the real world – Full Text
Virtual reality (VR) is a potentially promising tool for enhancing real-world locomotion in individuals with mobility impairment through its ability to provide personalized performance feedback and simulate real-world challenges. However, it is unknown whether novel locomotor skills learned in VR show sustained transfer to the real world. Here, as an initial step towards developing a VR-based clinical intervention, we study how young adults learn and transfer a treadmill-based virtual obstacle negotiation skill to the real world.
On Day 1, participants crossed virtual obstacles while walking on a treadmill, with the instruction to minimize foot clearance during obstacle crossing. Gradual changes in performance during training were fit via non-linear mixed effect models. Immediate transfer was measured by foot clearance during physical obstacle crossing while walking over-ground. Retention of the obstacle negotiation skill in VR and retention of over-ground transfer were assessed after 24 h.
On Day 1, participants systematically reduced foot clearance throughout practice by an average of 5 cm (SD 4 cm) and transferred 3 cm (SD 1 cm) of this reduction to over-ground walking. The acquired reduction in foot clearance was also retained after 24 h in VR and over-ground. There was only a small, but significant 0.8 cm increase in foot clearance in VR and no significant increase in clearance over-ground on Day 2. Moreover, individual differences in final performance at the end of practice on Day 1 predicted retention both in VR and in the real environment.
Overall, our results support the use of VR for locomotor training as skills learned in a virtual environment readily transfer to real-world locomotion. Future work is needed to determine if VR-based locomotor training leads to sustained transfer in clinical populations with mobility impairments, such as individuals with Parkinson’s disease and stroke survivors.
In recent years, virtual reality (VR) has been increasingly used to provide engaging, interactive, and task-specific locomotor training [1,2,3,4,5,6,7,8]. These studies have simulated walking in different environments such as parks or streets [3, 4], walking on a slope , or walking while avoiding obstacles [3,4,5, 7]. VR-based locomotor training frequently includes obstacle negotiation because it is an essential locomotor skill in the community [4, 5, 7] and tripping over obstacles is a common cause of falls in many patient populations . The clinical application of VR-based training interventions is predicated on the idea that practice in VR will lead to lasting changes in trained skills and that these changes will influence real-world behavior. Therefore, understanding how locomotor skills acquired in VR are retained and how these skills generalize to the real world is critical for determining the long-term utility of VR for locomotor rehabilitation.
The presence of lasting changes in a motor skill as a result of practice is a hallmark of motor learning and this retention process has been examined across a wide variety of real and virtual learning contexts. Retention of motor skills has been examined in response to VR training, particularly in fields such as flight and medical procedural training. For example, complex surgical and medical skills are performed faster and more accurately during a retention session following a single day of VR-based training [10,11,12,13]. Retention of locomotor skills is often explored in studies that analyze how people adapt to external perturbations such as a split-belt treadmill which has separate belts for the right and left legs [14,15,16], elastic force fields , robotic exoskeletons , or added loads . For instance, studies of split-belt treadmill adaptation have revealed that the increases in step length asymmetry observed during initial exposure to the belts moving at different speeds significantly decreased with subsequent exposures to the device [14,15,16]. A recent study by Krishnan and colleagues also investigated locomotor skill learning during a tracking task in which participants were instructed to match a pre-defined target of hip and knee trajectories as accurately as possible during the swing phase of the gait . They found that the reduction in tracking error achieved through practice is retained the following day. Although motor skill learning in VR and locomotor learning have been examined in isolation, it remains to be seen how locomotor skills are acquired and retained following training in a virtual environment.
Skill transfer, which is defined as “the gain or loss in the capability for performance in one task as a result of practice or experience on some other task” , is another key feature of motor learning. Skill transfer is particularly critical when skill acquisition occurs in a context that differs from the environment in which the skill is to be expressed. One way in which skill transfer has been evaluated during motor learning is by measuring how the adaptation of reaching in a robot-generated force field generalizes to unconstrained reaching. This work has shown that adaptation to reaching in a curl-field leads to increased curvature during reaching in free space [22, 23]. Moreover, studies of treadmill-based locomotor skill learning often evaluate transfer of learned skills from treadmill walking to over-ground. For example, during split-belt treadmill adaptation, the learned changes in interlimb symmetry partially transfer to over-ground walking . Further, VR-based training of obstacle negotiation on a treadmill led to increased walking speeds in the lab [5, 7] and community . However, the evaluation of transfer in these VR-based training studies was based on outcome measures such as walking speed that did not reflect the objective of the training task, which was the control of foot clearance obstacle negotiation. Therefore, it remains to be seen if the elements of skill from VR-training transfer to over-ground walking.
Underlying individual differences in learning can influence motor skill retention and transfer to new environments. For example, a recent study demonstrated that healthy older adults and people post-stroke who acquire a motor sequence skill at a faster rate also show greater retention of that skill . Similarly, the rate of skill acquisition for a reaching task during early training predicts faster trial completion time at 1-month follow-up . Lastly, the magnitude of improvements in reaching speed during skill acquisition predicts long-term changes in reaching speed in healthy individuals . Studies of individual differences in transfer have most often sought to understand how the practice of a skill with one limb influences performance of the same skill with the untrained limb. For example, interlimb transfer of motor skills acquired through visuomotor adaptation varies with handedness  and individual differences in baseline movement variability . However, far less work has sought to understand how individual differences in skill acquisition affect the transfer of learned skills to new environments. Overall, the influence of individual differences in skill acquisition on locomotor skill retention and sustained transfer has yet to be determined.
Here, we determined how individual differences in locomotor skill learning during virtual reality treadmill-based training influence retention and transfer of learned skills to over-ground walking in the real world. We used a VR-based version of a previously established precision obstacle negotiation task [30, 31] and asked 1) whether healthy young adults could learn to minimize clearance during virtual obstacle negotiation, 2) if the learned skill transferred to over-ground walking, 3) if the learned skill was retained in both VR and the real world after 24 h, and 4) if individual differences in the amount or rate of skill acquisition could predict retention and transfer. We hypothesized that 1) participants would reduce foot clearance in VR during practice on Day 1 and that 2) the reduced foot clearance in VR would transfer to over-ground obstacle negotiation. We also hypothesized that 3) the reduction in foot clearance in VR and over-ground would be retained in each environment after a 24-h retention period. Lastly, given that the rate and magnitude of the performance improvement during skill acquisition have been established as predictors of skill retention in previous studies, we also hypothesized that 4) these measures would predict retention of the learned skill in VR and over-ground. Given the growing use of VR for motor skill learning, our results may provide a unique opportunity to understand the factors that influence how training in VR might lead to long-term improvements in skilled locomotion. […]
[ARTICLE] Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial – Full Text
A recent study has demonstrated that a turning-based treadmill program yields greater improvements in gait speed and temporal symmetry than regular treadmill training in chronic stroke patients. However, it remains unknown how this novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in chronic stroke patients. The purpose of this study was to examine how a novel type of gait training, which is an unfamiliar but effective task for people with chronic stroke, enhances brain reorganization.
Subjects in the experimental and control groups received 30 min of turning-based treadmill training and regular treadmill training, respectively. Cortico-cortical connectivity and cortico-muscular connectivity during walking and gait performance were assessed before and after completing the 12-session training.
Eighteen subjects (n = 9 per group) with a mean age of 52.5 ± 9.7 years and an overground walking speed of 0.61 ± 0.26 m/s consented and participated in this study. There were significant group by time interactions for gait speed, temporal gait symmetry, and cortico-cortical connectivity as well as cortico-muscular connectivity in walk-related frequency (24–40 Hz) over the frontal-central-parietal areas. Compared with the regular treadmill training, the turning-based treadmill training resulted in greater improvements in these measures. Moreover, the increases in cortico-cortical connectivity and cortico-muscular connectivity while walking were associated with improvements in temporal gait symmetry.
Our findings suggest this novel turning-based treadmill training is effective for enhancing brain functional reorganization underlying cortico-cortical and corticomuscular mechanisms and thus may result in gait improvement in people with chronic stroke.
A recent study suggested that chronic stroke patients maintain the capacity to increase synchronization of neural activity between different brain regions as measured by EEG connectivity. These changes of functional connectivity in the motor cortex through neurofeedback correlate with improvements in motor performance . Previously, we demonstrated that a novel specific training, the turning-based treadmill program, yielded greater improvements in gait speed and temporal symmetry than regular treadmill training for people with chronic stroke . We presumed the turning-based treadmill training, which is a challenging and unfamiliar training task for chronic stroke patients, may facilitate brain reorganization and behavioral recovery . Thus, we sought to understand how such novel gait training promotes brain reorganization in this study.
An EEG-based method has the advantage of real-time recording during walking due to the relative ease of data acquisition. As indicated by the authors of the first study to use an EEG signal recorded during walking, the power increases within numerous frequency bands (3–150 Hz) in the sensorimotor cortex and is more pronounced during the end of the stance phase of walking . Source localization EEG analysis revealed the importance of the primary somatosensory, somatosensory association, primary motor and cingulate cortex in gait control . Focal lesions due to stroke may not only affect the functional connectivity of cortical areas  but also impede the neural transmission of descending motor pathways . Based on spectral analysis, the direct relationship of cortical activities with peripheral movements is still unknown. Accordingly, an analysis of EEG-EMG coherence recorded during treadmill walking was done by Petersen et al. , who demonstrated that cortical activity in the primary motor cortex within the gamma band (24–40 Hz) was transmitted via the corticospinal tract to the leg muscles during the swing phase of walking. In addition, a recent study confirmed the strong correlation between kinematic errors of the lower extremities and fronto-centroparietal connectivity during gait training and post-training in healthy subjects . However, it remains unknown how novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in individuals with chronic stroke. Therefore, the aims of the current study were to explore the effects of the turning-based treadmill training, a novel gait training program, on cortico-cortical connectivity and corticomuscular connectivity and to investigate the relationship between connectivity changes and gait performance in chronic stroke patients.[…]
Continue —> Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial | Journal of NeuroEngineering and Rehabilitation | Full Text
Regaining the Ability to Walk
Because an acquired neurologic injury (such as a stroke) affects both sensory and motor function, walking can be severely affected. Sensory changes, weakness, and spasticity affect movement strategies, which alter a person’s ability to successfully respond to losses of balance. A stroke affects how much and how often a person walks and also affects walking adaptability—the ability to adapt to different conditions during ambulation—as well as endurance. Gait training generally starts as soon as possible following a stroke, using manual techniques, task-specific training, strengthening, and, when available, body weight-assisted treadmill training and robotic devices.
An example of over-ground gait training.
Movement Strategies Altered by Stroke
A movement strategy or synergy is a flexible, repeatable pattern of movement that can be quickly and automatically accessed by the central nervous system. Movement strategies allow us to store and reuse patterns of movement that have been successful in the past. Strategies are efficient, automatic movement patterns that evolve over time. Each time a loss of balance threatens, the nervous system draws on these pre-programmed movement strategies to ensure the maintenance of balance.Movement strategies used by the nervous system to respond to perturbations are diminished following a stroke.
The ankle strategy is used in response to small perturbations is also called ankle sway. Source: Lauren Robertson.
The ankle strategy—also called ankle sway—is used in response to small perturbations or losses of balance. When a small loss of balance occurs—as when standing on a moving bus—the foot acts as a lever to maintain balance by making continuous automatic adjustments to the movement of the bus. When a small balance adjustment is needed, muscles close to the floor (anterior tibialis and gastrocnemius) activate first and flow upward in a distal to proximal pattern.
When a perturbation is too large to be successfully handled by the ankle strategy, the hip strategy is needed. When the hip strategyis used, movement is centered about the hip and ankle muscles (anterior tibialis and gastrocnemius) are almost silent. The muscles in the trunk activate first as activation flows downward to the legs in a proximal to distal pattern. So, if the bus stops suddenly and the body bends forward, the low back and hamstrings will contract in that order to return the body to upright.
If the perturbation is strong and your center of gravity moves well past your base of support, it is necessary to take a forward or backward step to regain balance. This is referred to as a stepping strategy. Studies have shown age-related changes in stepping in older adults. Compared to younger people, older adults initiate the stepping strategy in response to smaller losses of balance and tend to take several small steps rather than one larger step (Maki & McIlroy, 2006).
Arm movements have a considerable role in balance control and are part of the strategies discussed above. The upper limbs start to react at the very beginning of a disruption of balance and continue to be active as the body attempts to regain control. By automatically reaching and grasping for support, the arms perform a protective function. In the case of a small perturbation, upper limb movements can prevent a fall by shifting the center of gravity away from the imbalance.
When upper extremity paresis or spasticity is present, post stroke subjects exhibit poor protective reactions during a perturbation of balance. They demonstrate a deficit in anticipatory and reactive postural adjustments. These impairments of the affected upper limbs limit a person’s ability to recover from perturbations during functional tasks such as walking (Arya et al., 2014).
Even in the absence of a neurologic disorder, age-related changes affect upper extremity reaction time when balance is disrupted. Older adults reach for support surfaces more readily than younger adults but the reach-reaction time is slower. Increased tendency to reach for support and a slowing of these reactions have been found to be predictive of falling in daily activities (Maki & McIlroy, 2006).
Comparing Reflexes, Automatic Reactions, and Volitional Movement
Think for a moment that you are cooking dinner and accidentally touch a scalding hot fry pan. You feel the heat and withdraw instantaneously. You aren’t thinking “I better take my hand off the hot pan before it burns me”—your reflexes take care of that for you. The withdrawal is almost instantaneous because your nervous system senses danger and reflexively withdraws.
This type of reaction is used in movement strategies; they are slower than reflexes but faster than volitional movement. They are fast enough to help us respond to losses of balance without having to think.
This type of movement requires thought and is relatively slow compared to reflexive and automatic movement. Using our brains to think about movement isn’t very practical when we need something done really fast—by the time your brain warns you to bend your waist, step forward, or grab onto something when the bus stops abruptly, it’s already too late to regain balance.
Stand up next to your chair. Make sure you are standing on a flat, firm surface. Now close your eyes. Notice that your body sways a little—you are using the ankle strategy to stay balanced. Notice also that after a short amount of time you sway less—that means your nervous system is adjusting. Often, following a stroke, a person looses the ability to use the ankle strategy. This can have a profound impact on balance.
Stand up again. Ask someone to give you a little nudge from behind. Try not to take a step. If it was a truly small nudge you will likely bend at the waist to try to regain your balance. This is an example of the hip strategy.
Now ask your partner to give you a slightly bigger nudge from behind. If the nudge is big enough you’ll have to take a step. This is the stepping strategy.
We use these strategies automatically, all day long, without effort. Someone who has had a stroke can’t access these strategies as quickly as you can. If faced with a nudge from a passerby, or a bus starting/stopping, or a walk on uneven ground, the inability to adjust quickly may result in a fall.
Importance of Walking Early and Often
Regaining the ability to walk following a stroke is of paramount importance to patients and caregivers alike; improving balance and walking leads to greater independence and improves general well-being.
In the first week following a stroke, only one-third of patients are able to walk without assistance. In the following weeks, walking ability generally improves. At 3 weeks, or at hospital discharge, more than half of stroke survivors can walk unaided. By 6 months, more than 80% are able to walk independently without physical assistance from another person (Balasubramanian et al., 2014).
Following a stroke, walking can take a lot of energy; impaired muscle function, weakness, and poor cardiovascular conditioning can double the amount of energy expended. The high energy cost of walking can affect a person’s ability to participate in daily activities and lead to a vicious cycle where physical activity is avoided. For example, in one study, stroke patients walked 50% of the daily amount of matched sedentary adults and used 75% of their VO2 peak for walking at a submaximal rate (Danielsson et al., 2011).
Walking may improve more rapidly when patients are involved in setting specific goals. The results of several motor learning studies in which the person’s attention was focused on the outcome of an action rather than the action itself produced more effective performance than focusing on the quality of the movement (Carr & Shepherd, 2011).
In the hospital, an early goal for walking might be to walk to the next appointment, or to walk at least part of the way, rather than being transported in a wheelchair. Each day the patient should be encouraged to select a distance to walk independently and safely. Initially, this may be only a few steps. The goal is to walk the chosen distance a certain number of times a day, increasing distance as soon as possible, and keeping a record of progress, which gives the patient a specific focus (Carr & Shepherd, 2011).
Walking Adaptability, Stepping, and Postural Control
Walking is greatly dependent upon our ability to adapt to varying environmental conditions and tasks. Walking from the bedroom to the bathroom with a walker requires a different level of attention and adaptability than walking across a busy street carrying a bag of groceries. Even walking and talking can be a challenge for post stroke patients.
Over time, up to 85% of individuals with a stroke regain independent walking ability, but at discharge from inpatient rehab only about 7% can manage steps and inclines or walk the speeds and distances required to walk competently in the community. Limited ability to adjust to changes in the task and environment means a person either avoids walking in complex situations (a safety strategy) or has a heightened risk of falls when required to walk under these challenging conditions (Balasubramanian et al., 2014).
Despite its importance, assessment of walking adaptability has received relatively little attention. Frequently used assessments of walking ability after stroke involve walking short distances (such as the Timed Up and Go test) and examination of isolated limb movements (such as the Fugl-Meyer Assessment). Although valuable, these assessments do not take into account the skills needed to re-engage in safe and independent ambulation in the home and community. Comprehensive assessments and specific interventions are needed to improve walking adaptability (Balasubramanian et al., 2014).
In addition to the ability to adapt to different conditions and tasks, walking adaptability has two other requirements: (1) stepping, and (2) postural control (Shumway-Cook & Woollocott, 2012). Stepping involves the ability to generate and maintain a rhythmic, alternating gait pattern as well as the ability to start and stop. Postural control involves both the musculoskeletal and nervous systems.
To walk effectively, the central nervous system must:
- Generate the basic stepping pattern of rhythmic reciprocal limb movements while supporting the body against gravity and propelling it forward.
- Maintain control of posture (equilibrium) to keep the center of mass over a constantly moving base of support and maintain the body upright in space.
- Adapt to environmental circumstance or changes in the behavioral goal (Balasubramanian et al., 2014).
Source: Balasubramanian et al., 2014.
These components are especially necessary for complex tasks. For example, walking adaptability is crucial on uneven ground or cluttered terrains and when the task requires walking and turning or negotiating a curved path. There are endless combinations of task goals and environmental circumstances that must be considered to comprehensively capture walking adaptability (Balasubramanian et al., 2014).
Walking adaptability is very important for community ambulation. Patla and Shumway-Cook have described “dimensions” that affect a person’s ability to adapt while walking. These are external demands that must be met for successful community mobility:
- Distance (distance walked)
- Temporal factors (time needed to cross a busy street or crosswalk, ability to maintain the same speed as those around them)
- Ambient conditions (rain, heat, snow, etc.)
- Physical load (packages carried, number of doors that need to be opened)
- Terrain (stairs, curbs, slopes, uneven ground, grass, elevators, obstacles)
- Attentional demands (distractions in the environment, noise, cars, crowds, talking)
- Postural transitions (stopping, reaching, backing up, turning head, change direction)
- Traffic density (number of people within arm’s reach, unexpected collisions and near collisions with other people) (Shumway-Cook et al., 2002)
Improving Endurance for Walking
It is evident that many patients are discharged from inpatient rehabilitation severely deconditioned, meaning that their energy levels are too low for active participation in daily life. Physicians, therapists, and nursing staff responsible for rehabilitation practice should address this issue not only during inpatient rehabilitation but also after discharge by promoting and supporting community-based exercise opportunities. During inpatient rehabilitation, group sessions should be frequent and need to include specific aerobic training. Physical therapy must take advantage of the training aids available, including exercise equipment such as treadmills, and of new developments in computerized feedback systems, robotics, and electromechanical trainers.
Janet Carr and Roberta Sheperd
University of Sydney, Australia
Although many people affected by stroke have regained some ability to walk by the time they are discharged from rehab, many have low endurance, which limits their ability to perform household tasks or even to walk short distances. After a stroke, walking requires a much higher level of energy expenditure, and upon discharge many stroke patients are not necessarily functionalwalkers (Carr & Sheperd, 2011).
Functional walking is assessed using tests of speed, distance, and time. Minimal criteria for successful community walking include an independent walking velocity of 0.8 m/s or greater (about 2.6 feet/second), the ability to negotiate uneven terrain and curbs, and the physical endurance to walk 500 meters or more. In a review of 109 people discharged from physical therapy, only 7% achieved the minimum level. Cardiorespiratory fitness training can address both the efficiency with which people affected by stroke can walk and the distance they are able to achieve (Carr & Sheperd, 2011).
The loss of independent ambulation outdoors has been identified as one of the most debilitating consequences of stroke. Among stroke survivors 1 year after stroke, the most striking area of difficulty was low endurance measured by the distance walked in a 6-minute walk test. Those subjects able to complete this test were able to walk on average only 250 meters (820 feet) compared to the age-predicted distance of >600 meters (almost 2,000 feet), equivalent to 40% of their predicted ability and not far enough for a reasonable and active lifestyle. The detrimental effect of low exercise capacity and muscle endurance on functional mobility and on resistance to fatigue is likely to increase after discharge if follow-up physical activity and exercise programs are not available (Carr & Sheperd, 2011).
In 2002 the American Thoracic Society (ATS) published guidelines for the 6-minute walk test with the objective of standardizing the protocol to encourage its further application and to allow direct comparisons among different studies and populations. The American Thoracic Society guidelines include test indications and contraindications, safety measures, and a step-by-step protocol as well as assistance with clinical interpretation (Dunn et al., 2015).
Key components of the protocol include the test location, walkway length, measurements, and instructions. According to the American Thoracic Society protocol, the test should be performed on a flat, enclosed (indoor) walkway 30 m (just under 100 feet) in length. This protocol requires 180° turns at either end of the walkway and additional space for turning. The guidelines advise that shorter walkway lengths require more directional changes and can reduce the distances achieved. The influence of directional changes may be amplified in the stroke population, who characteristically have impaired balance, asymmetric gait patterns, and altered responses for turn preparation. Conversely, reducing the number of directional changes may increase the distance achieved (Dunn et al., 2015).
Body Weight-Supported Treadmill Training
Body weight-supported treadmill training (BWSTT) is an increasingly being used to encourage early walking following a stroke. It is a rehabilitation technique in which patients walk on a treadmill with their body weight partly supported. Body weight-supported treadmill training augments walking by enabling repetitive practice of gait (Takeuchi & Izumi, 2013).
In patients who have experienced a stroke, partial unloading of the lower extremities by the body weight-support system results in straighter trunk and knee alignment during the loading phase of walking. It can also improve swing1 asymmetry, stride length, and walking speed, and allows a patient to practice nearly normal gait patterns and avoid developing compensatory walking habits, such as hip hiking and circumduction2 (Takeuchi & Izumi, 2013).
1Swing phase of gait: during walking, the swing phase begins as the toe lifts of the ground, continues as the knee bends and the leg moves forward, and ends when the heel come in contact with the ground.
2Circumduction: a gait abnormality in which the leg is swung around and forward in a semi-circle. The hip is often hiked up to create enough room for the leg to swing forward.
Treadmill walking allows for independent and semi-supervised practice, for those with more ability, as well as improving aerobic capacity and increasing walking speed and endurance. The very early practice of assisted over-ground and harness-supported treadmill walking is probably critical to good post-discharge functional capacity in terms of both performance and energy levels (Carr & Shepherd, 2011).
The Locomotor Experience Applied Post Stroke (LEAPS) trial—the largest stroke rehabilitation study ever conducted in the United States—set out to compare the effectiveness of the body weight-supported treadmill training with walking practice. Participants started at two different stages—two months post stroke (early locomotor training) and six months post stroke (late locomotor training). The locomotor training was also compared to a home exercise program managed by a physical therapist, which was aimed at enhancing flexibility, range of motion, strength, and balance as a way to improve walking. The primary measure was improvement in walking at 1 year after the stroke (NINDS, 2011).
In the LEAPS trial, stroke patients who had physical therapy at home improved their ability to walk just as well as those who were treated in a training program that requires the use of a body weight-supported treadmill device followed by walking practice. The study, funded by the NIH, also found that patients continued to improve up to 1 year after stroke—defying conventional wisdom that recovery occurs early and tops out at 6 months. In fact, even patients who started rehabilitation as late as 6 months after stroke were able to improve their walking (NINDS, 2011).
“We were pleased to see that stroke patients who had a home physical therapy exercise program improved just as well as those who did the locomotor training,” said Pamela W. Duncan, principal investigator of LEAPS and professor at Duke University School of Medicine. “The home physical therapy program is more convenient and pragmatic. Usual care should incorporate more intensive exercise programs that are easily accessible to patients to improve walking, function, and quality of life.”
Robotic Gait Training Devices
Several lower-limb rehabilitation robots have been developed to restore mobility of the affected limbs. These systems can be grouped according to the rehabilitation principle they follow:
- Treadmill gait trainers
- Foot-plate-based gait trainers
- Over-ground gait trainers
- Stationary gait trainers
- Ankle rehabilitation systems
- Stationary systems
- Active foot orthoses (Díaz et al., 2011)
Source: Diaz et al., 2011.
Many robotic systems have been developed aiming to automate and improve body weight-assisted treadmill trainers as a means for reducing therapist labor. Usually these systems are based on exoskeleton type robots in combination with a treadmill. One such system—the Lokomat—consists of a robotic gait orthosis and an advanced body weight-support system, combined with a treadmill. It uses computer-controlled motors (drives) that are integrated in the gait orthosis at each hip and knee joint. The drives are precisely synchronized with the speed of the treadmill to ensure a precise match between the speed of the gait orthosis and the treadmill (Díaz et al., 2011).
The LokoHelp gait trainer “Pedago.” Source: Diaz et al., 2011.
The LokoHelp is another device developed for improving gait after brain injury. The LokoHelp is placed in the middle of the treadmill surface, parallel to the walking direction and fixed to the front of the treadmill with a simple clamp. It also provides a body weight-support system. Clinical trials have shown that the system improves the gait ability of the patient in the same way as the manual locomotor training; however, the LokoHelp required less therapeutic assistance and thus therapist discomfort is reduced. This fact is a general conclusion for almost all robotic systems to date (Díaz et al., 2011).
Source: Diaz et al., 2011.
Over-ground gait trainers consist of robots that assist the patient in walking over ground. These trainers allow patients to move under their own control rather than moving them through predetermined movement patterns. The KineAssist is one robotic device used for gait and balance training. It consists of a custom-designed torso and pelvis harness attached to a mobile robotic base. The robot is controlled according to the forces detected from the subject by the load cells located in the pelvic harness (Díaz et al., 2011).
Source: Diaz et al., 2011.
ReWalk is a wearable, motorized quasi-robotic suit that can be used for therapeutic activities. ReWalk uses a light, wearable brace support suit that integrates motors at the joints, rechargeable batteries, an array of sensors, and a computer-based control system. Upper-body movements of the user are detected and used to initiate and maintain walking processes (Díaz et al., 2011).
The capacity of robots to deliver high-intensity and repeatable training make them potentially valuable tools to provide high-quality treatment at a lower cost and effort. These systems can also be used at home to allow patients to perform therapies independently, not replacing the therapist but supporting the therapy program. However, despite the attractiveness of robotic devices, clinical studies still show little evidence for the superior effectiveness of robotic therapy compared to current therapy practices, although robotics have been shown to reduce therapist effort, time, and costs (Díaz et al., 2011).
by Meri K. Slaugenhaupt, MPT, and Valerie Bucek, MA, CCC-SLP/L
According to the Centers for Disease Control and Prevention, someone in the United States has a stroke every 40 seconds. Someone dies from a stroke every 4 minutes. It is a leading cause of long-term disability. A stroke occurs when there is a disruption in blood flow to the brain. The most common kind of stroke, ischemic stroke, occurs when a clot or mass obstructs a blood vessel. A hemorrhagic stroke occurs when a weakened blood vessel ruptures.
This article follows the treatment of stroke survivor Greg Myers, who was finishing his workday when he suddenly became confused and had difficulty walking and talking. A co-worker called Emergency Medical Services, and Myers was transported to the nearest acute care primary stroke center for treatment. Myers had suffered a right cerebellar hemorrhage. His hospital course was complicated by the need for evacuation of the hematoma, post-occipital craniotomy, and wound dehiscence. After several days of acute medical care and monitoring, it was determined that Myers would benefit from intensive multidisciplinary rehabilitation services to address his residual physical deficits and cognitive needs. To begin his stroke rehabilitation journey, Myers chose HealthSouth Harmarville Rehabilitation Hospital (which will be known as Encompass Health Rehabilitation Hospital of Harmarville beginning January 1, 2019).
Since 2002, HealthSouth Harmarville has been certified as a Joint Commission Disease-Specific Care Stroke Program. The team follows evidence-based Clinical Practice Guidelines (CPG) for treatment of individuals with stroke. By following these guidelines, the team has confidence that treatments are based upon the most current evidence-based research and philosophies.
Comprehensive rehabilitation services, such as those provided at HealthSouth Harmarville, are found to be one of the most effective ways to achieve functional recovery and independence after a stroke. Intensive rehabilitation services facilitates neuroplasticity and recovery of motor function. Neuroplasticity is the ability for the brain to “rewire” or adapt to new circumstances by reorganizing synaptic connections. By engaging in therapy that is challenging, repetitive, and task specific, motor pathways that have been disrupted by the stroke can be rewired and strengthened.
Reducing Complications of Stroke
One of the goals of the clinical practice guidelines is to reduce the complications of stroke. One of the most frequent complications following a stroke is difficulty swallowing, or dysphagia. Stroke survivors with dysphagia have an increased risk of pneumonia, dehydration, and malnutrition. Instrumental assessment in the form of a Modified Barium Swallow study (MBS) or Fiber-Optic Endoscopic Evaluation of Swallowing (FEES) determine an appropriate, safe diet and the course of treatment. Swallowing difficulty is treated by exercise, diet modification, and technology, such as neuromuscular electrical stimulation.
Early therapy intervention is also important to maximize motor recovery in our stroke patients. Deconditioning and non-use are a hurdle to restoring function, especially with the elderly stroke population. Physiological changes and complications as a result of prolonged bedrest can lead to additional loss of muscle mass, contractures, skin breakdown, and deep vein thrombosis, all of which further hinder the stroke-recovery process.
Technology and the Path to Walking
Being able to walk again is a common goal shared by most stroke survivors, and Myers was no exception. Studies show that stroke affects mobility in greater than half of stroke survivors. Those suffering from gait disturbances often have further difficulties with balance and cardiovascular endurance, and are subsequently more likely to fall. Therefore, improvements achieved with gait function frequently carry over to improvements in many other aspects of daily living.
In the past decade, technology has moved to the forefront of therapeutic intervention as an adjunct to conventional practice. This is true for all disciplines and ranges from Vital Stimulation in the treatment of dysphagia to robotics in the treatment of movement disorders.
Body weight-supported technology is one such area of technological advancement being utilized for gait training. Partial body weight (PBW)-supported devices are designed to use a harness and/or suspension system to assist with standing and safety during ambulation. When partial body weight devices are used over a treadmill, the therapist is able to change gait speed and work on gait quality under controlled, safe conditions. However, many PBW devices do not require use of a treadmill and can be used over the ground while providing similar training benefits to patients.
Automated technology incorporates the use of robotics, using attachments to the patient’s hip, knees, and ankles. These robotics guide the patient’s lower-extremity movement and promote normal movement throughout the entire gait cycle. Robotic body weight support is generally used with more involved patients who have significant difficulty with lower extremity movement. These devices allow the therapist to gradually decrease the support provided as gait improves.
Fall Protection and Balance
A clinical advantage that these technologies have over other conventional gait training is the reduced support required by the therapist. When asked about using a PBW support device, Tammy Whitlinger, a physical therapist assistant at HealthSouth Harmarville for 28 years, states, “I am able to safely initiate gait training earlier, and my patients are less anxious about the training because they know that they can’t fall.”
Balance deficits resulting from a stroke can also be very debilitating and frustrating for individuals. Since Myers had a stroke that affected the cerebellar part of his brain, balance training was also a major component of his therapy program. Myers’s balance program included a variety of approaches including altering visual feedback and multi-surface challenges. Equipment utilized for balance deficits can be as simple as carpet or foam. More complex devices are designed to use interactive technology and visual feedback to further analyze a patient’s posture and balance deficits.
Treadmills are another piece of technology commonly found in the clinic that are used to improve motor recovery after stroke. Treadmill training can be used with or without partial body weight support. When used along with conventional therapy, treadmill training has been shown to improve gait quality and efficiency, strength, and cardiovascular fitness. Other adjunct modalities are also utilized by physical therapists to address aerobic fitness and reciprocal movements of the lower extremities, such as stepper machines, elliptical trainers, and stationary/recumbent bikes.
Upper Extremity Dysfunction
Advanced technology used for the treatment of upper extremity dysfunction has also impacted stroke rehabilitation. Improving deficits in fine motor control, coordination, and weakness are often a focus of treatment in stroke recovery. Electrical stimulation, biofeedback, or robotics are utilized in many technologies to retrain arm movements and hand function. Some of these devices are even coupled with gaming to provide motivation and entertainment for the patient while exercising.
Family/caregiver involvement early on is very beneficial to a successful inpatient rehabilitation stay and transition to home. Our Clinical Practice Guidelines recommend that patients and caregivers be educated throughout the entire stay to learn about disease process, expected outcomes, treatment goals, and follow-up support services available in the home and community. As part of our discharge planning and preparation for a safe transition home, we completed a home visit for Myers. This is when the physical and occupational therapist team takes the patient home in order to problem-solve accessibility issues and to perform caregiver training in their own environment. By doing this, Myers and his wife were less anxious and fearful about their transition home.
Neuro-Focused Outpatient Rehab
Quality inpatient rehabilitation is a vital step in the journey of returning to community participation. Many patients choose to receive home health services after inpatient rehabilitation to assist with the transition to home. Myers briefly utilized home health before initiating the next stage of his recovery, which was a neuro-focused outpatient program found at HealthSouth Harmarville. Outpatient therapy provides an opportunity for stroke survivors to build endurance and to practice skills in higher levels of difficulty. Concerns and issues that have arisen from community integration can be incorporated into treatment and resolved. Instrumental activities of daily living are also a focus of the outpatient program. Participation in activities such as disease-specific support groups and wellness programs can help to facilitate return to the community.
HealthSouth Harmarville offers the entire continuum of care for patients, ranging from inpatient rehabilitation to home health to outpatient services to community support groups. Myers’s wife, Cathy, has become an active participant in the hospital’s Stroke Support Group, attending the educational programs and interacting with families of other stroke survivors. Myers, himself, continues to make gains in physical functioning, daily living skills, communication, and cognitive skills in outpatient therapy. He has returned to some of the leisure activities he enjoyed before his stroke. The couple took another step toward normalcy by going on a vacation to Aruba in August.
Additionally, Greg Myers was honored at the hospital’s National Rehabilitation Awareness Week celebration in September as one of five Rehab Champions treated in the last year who displayed determination, a positive attitude, and the ability to overcome obstacles in order to be successful. RM
Meri K. Slaugenhaupt, MPT, has served on the HealthSouth Harmarville Rehabilitation Hospital team since 1993, beginning as a physical therapist and now serves as the team’s program champion of the stroke program. In this role, Slaugenhaupt has obtained Stroke Joint Commission Disease Specific Certification, making HealthSouth Harmarville the first rehabilitation hospital to achieve this status in 2002. Under Slaugenhaupt’s leadership the hospital has achieved its 8th Joint Commission disease-specific care certification in 2017 for the stroke program. She earned her bachelor’s degree in physiology with a minor in exercise science from Penn State University in 1991. She then earned her master’s in physical therapy at the University of Pittsburgh.
Valerie Bucek, MA, CCC-SLP/L, has been a member of the HealthSouth Harmarville Rehabilitation Hospital team for more than 25 years. She began her work there as a staff speech pathologist and a speech therapy supervisor prior to her current role as the hospital’s therapy manager. Bucek received a bachelor’s degree in speech pathology from Duquesne University and a master’s degree in communication disorders from the University of Pittsburgh. She is one of the leaders of the hospital’s stroke and Parkinson’s disease programs, is founder and facilitator of the HealthSouth Harmarville Community Stroke Support Group, and is an affiliate for the ASHA Special Interest Division-Adult Neurogenic Communication Disorders. For more information, contactRehabEditor@medqor.com.
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“Being a professional 3D animator for over 25 years, and having worked on very high-end virtual reality projects, the challenge of ‘how to enable 360-degree locomotion on a stationary surface‘ is a question that burned in my mind since the late 1990’s. I contemplated this obstacle to freedom of VR locomotion for months and years. Then, I was lying in bed one night further toiling with the omnidirectional locomotion surface question, and it dawned on me . . . a water balloon!” said Neil Epstein, OmniPad’s CEO and president. “I realized that when you take a small water balloon, press it firmly between your palms so that the top and bottom surfaces are completely flat, and then motion your hands in opposing circular directions, the flattened water balloon freely revolves in all directions while still remaining completely flat on both sides. Hence, the core mechanics of the OmniPad were born.”
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- A Multitude Of Uses Possible Uses: With the appropriate Virtual Reality environments, the OmniPad offers a comprehensive gaming experience, as well as highly-effective training of training first responders and soldiers, and allows architects, engineers, and home buyers to visualize buildings and real estate, and even has significant applications in sports training, eSports competitions, and rehabilitation, among so many other applications.
OmniPad has launched a SEC regulation crowdfunding equity campaign, (https://wefunder.com/omnipad.company ), to share awareness and the potential capabilities of this awe-inspiring product. You can check out the company’s YouTube channel, (https://www.youtube.com/channel/UCsR1sCPunIZs2G28DFmmn9A), to see the OmniPad in action.
OmniPad is a startup company comprised of some of the brightest and creative minds available. The company’s team includes the world’s foremost expert on omnidirectional locomotion surface technology and Stanford Engineering graduate, David Carmein, the EMMY award-winning 3-D artist and conceptual mind behind OmniPad, Neil Epstein, J.D., and the marketing specialties of Jordan Robinson, Orentheal Williams, and Kenneth Dunn.
Conservaco/The Ignite Agency
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