UC San Francisco scientists have improved mobility in rats that had experienced debilitating strokes by using electrical stimulation to restore a distinctive pattern of brain cell activity associated with efficient movement. The researchers say they plan to use the new findings to help develop brain implants that might one day restore motor function in human stroke patients.
After a stroke, roughly one-third of patients recover fully, one-third have significant lingering movement problems, and one-third remain virtually paralyzed, said senior author Karunesh Ganguly, MD, PhD, associate professor of neurology and a member of the UCSF Weill Institute for Neurosciences. Even patients who experience partial recovery often continue to struggle with “goal-directed” movements of the arms and hands, such as reaching and manipulating objects, which can be crucial in the workplace and in daily living.
“Our main impetus was to understand how we can develop implantable neurotechnology to help stroke patients,” said Ganguly, who conducts research at the San Francisco VA Health Care System. “There’s an enormous field growing around the idea of neural implants that can help neural circuits recover and improve function. We were interested in trying to understand the circuit properties of an injured brain relative to a healthy brain and to use this information to tailor neural implants to improve motor function after stroke.”
Over the past 20 years, neuroscientists have presented evidence that coordinated patterns of neural activity known as oscillations are important for efficient brain function. More recently, low-frequency oscillations (LFOs)—which were first identified in studies of sleep—have been specifically found to help organize the firing of neurons in the brain’s primary motor cortex. The motor cortex controls voluntary movement, and LFOs chunking the cells’ activity together to ensure that goal-directed movements are smooth and efficient.
In the new study, published in the June 18, 2018 issue of Nature Medicine, the researchers first measured neural activity in rats while the animals reached out to grab a small food pellet, a task designed to emulate human goal-directed movements. They detected LFOs immediately before and during the action, which inspired the researchers to investigate how these activity patterns might change after stroke and during recovery.
To explore these questions, they caused a stroke in the rats that impaired the animals’ movement ability, and found that LFOs diminished. In rats that were able to recover, gradually making faster and more precise movements, the LFOs also returned. There was a strong correlation between recovery of function and the reemergence of LFOs: animals that fully recovered had stronger low-frequency activity than those that partially recovered, and those that didn’t recover had virtually no low-frequency activity at all.
To try to boost recovery, the researchers used electrodes to both record activity and to deliver a mild electrical current to the rats’ brains, stimulating the area immediately surrounding the center of the stroke damage. This stimulation consistently enhanced LFOs in the damaged area and appeared to improve motor function: when the researchers delivered a burst of electricity right before a rat made a movement, the rat was up to 60 percent more accurate at reaching and grasping for a food pellet.
“Interestingly, we observed this augmentation of LFOs only on the trials where stimulation was applied,” said Tanuj Gulati, PhD, a postdoctoral researcher in the Ganguly lab who is co-first author of the study, along with Dhakshin Ramanathan, MD, PhD, now assistant professor of psychiatry at UC San Diego, and Ling Guo, a neuroscience graduate student at UCSF.
“We are not creating a new frequency, we are amplifying the existing frequency,” added Ganguly. “By amplifying the weak low-frequency oscillations, we are able to help organize the task-related neural activity. When we delivered the electrical current in step with their intended actions, motor control actually got better.”
The researchers wanted to know whether their findings might also apply to humans, so they analyzed recordings made from the surface of the brain of an epilepsy patient who had suffered a stroke that had impaired the patient’s arm and hand movements. The recordings revealed significantly fewer LFOs than recordings made in two epilepsy patients who hadn’t had a stroke. These findings suggest that, just like in rats, the stroke had caused a loss of low-frequency activity that impaired the patient’s movement.
Physical therapy is the only treatment currently available to aid stroke patients in their recovery. It can help people who are able to recover neurologically get back to being fully functional more quickly, but not those whose stroke damage is too extensive. Ganguly hopes that electrical brain stimulation can offer a much-needed alternative for these latter patients, helping their brain circuits to gain better control of motor neurons that are still functional. Electrical brain stimulation is already widely used to help patients with Parkinson’s disease and epilepsy, and Ganguly believes stroke patients may be the next to benefit.
Other UCSF contributors to the work included Gray Davidson; April Hishinuma; Seok-Joon Won, PhD, associate adjunct professor of neurology; Edward Chang, MD, professor of neurosurgery and William K. Bowes Jr. Biomedical Investigator; and Raymond Swanson, MD, professor of neurology. They were joined by Robert T. Knight, MD, professor of psychology and neuroscience at UC Berkeley.
The research was supported in part by funding from the National Institute of Neurological Disorders and Stroke; the National Institute of Mental Health; the Agency for Science, Technology, and Research (A*STAR), in Singapore; the U.S. Department of Veterans Affairs, and the Burroughs Wellcome Fund.
In the western world, stroke has been identified as the leading cause of disability in adults. Impairment to the arm/hand and depressive symptoms seem to be among the most frequent resultants of stroke. This article describes a collaborative occupational therapy and music therapy intervention for post-stroke arm/hand recovery. The intervention itself combines principles of music therapy with tablet technology and functional electrical stimulation. The implementation of this novel intervention, described in this clinical case report, has implications for benefits to physical and motivational aspects of rehabilitation. Recommendations for further research of this intervention are also discussed.
This retrospective clinical case report will examine the implementation of a novel intervention combining a Functional Electrical Stimulation (FES) protocol with an iPad application. A 74-year-old female retired pianist and Professor of Music was admitted to a rehabilitation hospital following a left pontine stroke. On assessment, she was unable to use her right upper limb functionally. Conventional occupational therapy commenced soon after admission and consisted of functional retraining, including FES to the wrist and finger extensors. At week 4, the Registered Music Therapist (RMT) and Occupational Therapist (OT) collaborated to commence a trial of forearm FES in combination with an iPad-based music making application; ThumbJam. This application was used to encourage the patient to participate in touch sensitive musical improvisation using the affected hand in an attempt to promote engagement in complex motor patterns and non-verbal expression. Within 3 weeks, the patient was able to use ThumbJam without the FES, progressed to the keyboard in 4 weeks and has since commenced independent scales on the piano at home (21 weeks), as well as successful use of the upper limb in Activities of Daily Living (ADLs). On follow up (7 months), the patient reflected on the motivating elements of the intervention that helped her to achieve a functional outcome in her upper limb. This retrospective clinical case report will review the evidence with regard to FES and music therapy, outline the treatment protocol used and make recommendations for future research of “FES+ThumbJam” in upper limb stroke rehabilitation.[…]
In recent years, the assistive technologies and stroke rehabilitation methods have been empowered by the use of virtual reality environments and the facilities offered by brain computer interface systems and functional electrical stimulators. In this paper, a therapy system for stroke rehabilitation based on these revolutionary techniques is presented. Using a virtual reality Oculus Rift device, the proposed system ushers the patient in a virtual scenario where a virtual therapist coordinates the exercises aimed at restoring brain function. The electrical stimulator helps the patient to perform rehabilitation exercises and the brain computer interface system and an electrooculography device are used to determine if the exercises are executed properly. Laboratory tests on healthy people led to system validation from technical point of view. The clinical tests are in progress, but the preliminary results of the clinical tests have highlighted the good satisfaction degree of patients, the quick accommodation with the proposed therapy, and rapid progress for each user rehabilitation.
The worldwide statistics reported by World Health Organization highlight that stroke is the third leading cause of death and about 15 million people suffer stroke worldwide each year . Of these, 5 million are permanently disabled needing long time assistance and only 5 million are considered socially integrated after recovering. Recovering from a stroke is a difficult and long process that requires patience, commitment, and access to various assistive technologies and special devices. Rehabilitation is an important part of recovering and helps the patient to keep abilities or gain back lost abilities in order to become more independent. Taking into account the depression installed after stroke, it is very important for a patient to benefit from an efficient and fast rehabilitation program followed by a quick return to community living . In the last decade, many research groups are focused on motor, cognitive, or speech recovery after stroke like Stroke Centers from Johns Hopkins Institute , ENIGMA-Stroke Recovery , or StrokeBack Consortium funded by European Union’s Seventh Framework Programme . Important ICT companies bring a major contribution to the development of technologies and equipment that can be integrated into rehabilitation systems. For example, Stroke Recovery with Kinect is a research project to build an interactive and home-rehabilitation system for motor recovery after a stroke based on Microsoft Kinect technology .
In the last years, the virtual reality (VR) applications received a boost in development due to VR headset prices that dropped below $1000, allowing them to become a mass-market product . The VR was and still is especially used for military training or video games to provide some sense of realism and interaction with the virtual environment to its users . Now it attracts more and more the interest of physicians and therapist which are exploring the potential of VR headset and augmented reality (AR) to improve the neuroplasticity of the brain, to be used in neurorehabilitation and treatment of motor/mental disorders . However, considering the diversity of interventions and methods used, there is no evidence that VR therapy alone can be efficacious compared with other traditional therapies for a particular type of impairment . This does not mean that the potential of VR was overestimated and the results are not the ones that were expected. The VR therapy must be complemented with other forms of rehabilitation technologies like robotic therapy, brain computer interface (BCI) and functional electrical stimulation (FES) therapy, and nevertheless traditional therapy to provide a more targeted approach .
SaeboVR is a virtual rehabilitation system exclusively focusing on activities of daily living and uses a virtual assistant that appears on the screen to educate and facilitate performance by providing real-time feedback . The neurotechnology company MindMaze has introduced MindMotion PRO, a 3D virtual environment therapy for upper limb neurorehabilitation incorporating virtual reality-based physical and cognitive exercise games into stroke rehabilitation programs . At New York Dynamic Neuromuscular Rehabilitation, the CAREN (Computer Assisted Rehabilitation Environment) based on VR is currently used to treat patients poststroke and postbrains injuries . EVREST Multicentre has achieved remarkable results regarding the use of VR exercises in stroke rehabilitation .
Motor imagery (MI) is a technique used in poststroke rehabilitation for a long time ago. One of its major problems was that there was not an objective method to determine whether the user is performing the expected movement imagination. MI-based BCIs can quantify the motor imagery and output signals that can be used for controlling an external device such as a wheelchair, neuroprosthesis, or computer. The FES therapy combined with MI-based BCI became a promising technique for stroke rehabilitation. Instead of providing communication, in this case, MI is used to induce closed-loop feedback within conventional poststroke rehabilitation therapy. This approach is called paired stimulation (PS) due to the fact that it pairs each user’s motor imagery with stimulation and feedback, such as activation of a functional electrical stimulator (FES), avatar movement, and/or auditory feedback . Recent research from many groups showed that MI can be recorded in the clinical environment from patients and used to control real-time feedback and at the same time, they support the hypothesis that PS could improve the rehabilitation therapy outcome [17–21].
In a recent study, Irimia et al.  have proved the efficacy of combining motor imagery, bar feedback, and real hand movements by testing a system combining a MI-based BCI and a neurostimulator on three stroke patients. In every session, the patients had to imagine 120 left-hand and 120 right-hand movements. The visual feedback was provided in form of an extending bar on the screen. During the trials where the correct imagination was classified, the FES was activated in order to induce the opening of the corresponding hand. All patients achieved high control accuracies and exhibited improvements in motor function. In a later study, Cho et al.  present the results of two patients who performed the BCI training with first-person avatar feedback. After the study, both patients reported improvements in motor functions and both have improved their scores on Upper Extremity Fugl-Meyer Assessment scale. Even if the number of patients presented in these two studies is low, they support the idea that this kind of systems may bring additional benefits to the rehabilitation process outcome in stroke patients.
2. General System Architecture
The BCI-FES technique presented in this paper is part of a much more complex system designed for stroke rehabilitation called TRAVEE , presented in Figure 1. The stimulation devices, the monitoring devices, the VR headset, and a computer running the software are the main modules of the TRAVEE system. The stimulation devices help the patient to perform the exercises and the monitoring devices are used to determine if the exercises are executed properly, according to the proposed scenarios. Actually, the TRAVEE system must be seen as a software kernel that allows defining a series of rehabilitation exercises using a series of USB connectable devices. This approach is very useful because it offers the patient the options to buy, borrow, or rent the abovementioned devices according to his needs and after connection, the therapist may choose the suitable set of exercises.[…]
VALENCIA, Calif., March 26, 2018 /PRNewswire/ — Bioness, Inc., the leading provider of cutting-edge, clinically supported rehabilitation therapies, today announced that it received clearance from the U.S. Food and Drug Administration (FDA) for the myBionessTM mobile app for use with the L300 Go™ System.
The new myBioness™ mobile iOS application allows home users to control their L300 Go system including ability to change stimulation modes between gait and training along with adjusting personal pre-set intensities to meet their daily activity demands. The app has been designed to keep users engaged in the rehabilitation process and motivated to meet their recovery goals with ability to track activity, set personal goals and review their progress over time using dynamic reporting capabilities.
Gait movement disorders, such as foot drop and knee instability, are often associated with an upper motor neuron disease such as stroke and multiple sclerosis as well as injuries to the brain and spinal cord. Individuals with an impaired gait have less control over their lower extremity muscles and are at an increased risk for falls. The L300 Go is the first functional electrical stimulation (FES) system to offer 3D motion detection of gait events and muscle activation using data from a 3-axis gyroscope and accelerometer. Patient movement is monitored in all three kinematic planes and stimulation is deployed precisely when needed during the gait cycle. An adaptive, learning algorithm accommodates changes in gait dynamics, and a high speed processor that deploys stimulation within 10 milliseconds of detecting a valid gait event. This rapid, reliable response is critical and supports user confidence.
“Technological innovations including 3D motion detection and multi-channel stimulation work together to improve treatment efficiency and promote patient mobility,” said Todd Cushman, President and CEO of Bioness. “At Bioness, we are focused on improving the lives of patients through technology and are proud to add the myBioness mobile application to the L300 Go portfolio of products.”
The L300 Go System was cleared by the U.S. Food and Drug Administration on January 27, 2017 with formal approval of the upgraded mobile application clearance dated March 9, 2018. The system is indicated to provide ankle dorsiflexion in adult and pediatric individuals with foot drop and/or assist knee flexion or extension in adult individuals with muscle weakness related to upper motor neuron disease/injury (e.g., stroke, damage to pathways to the spinal cord). The L300 Go System electrically stimulates muscles in the affected leg to provide ankle dorsiflexion of the foot and/or knee flexion or extension; thus, it also may improve the individual’s gait.
Bioness will begin commercial release of the myBionessTM mobile app in the spring of 2018. The L300 Go Systems are commercially available since the summer of 2017.
About Bioness, Inc.
Bioness is the leading provider of innovative technologies helping people regain mobility and independence. Bioness solutions include implantable and external neuromodulation systems, robotic systems and software based therapy programs providing functional and therapeutic benefits for individuals affected by pain, central nervous system disorders and orthopedic injuries. Currently, Bioness offers six medical devices within its commercial portfolio which are distributed and sold on five continents and in over 25 countries worldwide. Our technologies have been implemented in the most prestigious and well-respected institutions around the globe with approximately 90% of the top rehabilitation hospitals in the United States currently using one or more Bioness solution. Bioness has a singular focus on aiding large, underserved customer groups with innovative, evidence-based solutions and we will continue to develop and make commercially available new products that address the growing and changing needs of our customers. Individual results vary. Consult with a qualified physician to determine if this product is right for you. Contraindications, adverse reactions and precautions are available online at www.bioness.com.
Functional electrical stimulation (FES) is important in gait rehabilitation for patients with dropfoot. Since there are time-varying velocities during FES-assisted walking, it is difficult to achieve a good movement performance during walking. To account for the time-varying walking velocities, seven poststroke subjects were recruited and fuzzy logic control and a linear model were applied in FES-assisted walking to enable intensity- and duration-adaptive stimulation (IDAS) for poststroke subjects with dropfoot. In this study, the performance of IDAS was evaluated using kinematic data, and was compared with the performance under no stimulation (NS), FES-assisted walking triggered by heel-off stimulation (HOS), and speed-adaptive stimulation. A larger maximum ankle dorsiflexion angle in the IDAS condition than those in other conditions was observed. The ankle plantar flexion angle in the IDAS condition was similar to that of normal walking. Improvement in the maximum ankle dorsiflexion and plantar flexion angles in the IDAS condition could be attributed to having the appropriate stimulation intensity and duration. In summary, the intensity- and duration-adaptive controller can attain better movement performance and may have great potential in future clinical applications.
Stroke is a leading cause of disability in the lower limb, such as dropfoot (1). A typical cause of dropfoot is muscle weakness, which results in a limited ability to lift the foot voluntarily and an increased risk of falls (2–4). Great effort is made toward the recovery of walking ability for poststroke patients with dropfoot, such as ankle–foot orthoses (5), physical therapy (6), and rehabilitation robot (7).
Functional electrical stimulation (FES) is a representative intervention to correct dropfoot and to generate foot lift during walking (8, 9). The electrical pulses were implemented via a pair of electrodes to activate the tibialis anterior (TA) muscle and to increase the ankle dorsiflexion angle. The footswitch or manual switch was used to time the FES-assisted hemiplegic walking in previous studies, while they were only based on open-loop architectures. The output parameters of the FES required repeated manual re-setting and could not achieve an adaptive adjustment during walking (10, 11). Some researchers have found that the maximum ankle dorsiflexion angle by using FES with a certain stimulation intensity had individual differences due to the varying muscle tone and residual voluntary muscle activity and varied during gait cycles (12, 13). If the stimulation intensity was set to a constant value during the whole gait cycle, the result could be that the muscle fatigues rapidly (14). Another important problem was that the FES using fixed stimulation duration from the heel-off event to the heel-strike event would affect the ankle plantar flexion angle (15, 16).
Closed-loop control was an effective way to adjust the stimulation parameters automatically, and several control techniques have been proposed (17, 18). Negård et al. applied a PI controller to regulate the stimulation intensity and obtain the optimal ankle dorsiflexion angle during the swing phase (19). A similar controller was also used in Benedict et al.’s study, and the controller was tested in simulation experiments (20). Cho et al. used a brain–computer interface to detect a patient’s motion imagery in real time and used this information to control the output of the FES (21). Laursen et al. used the electromechanical gait trainer Lokomat combined with FES to correct the foot drop problems for patients, and there were significant improvements in the maximum ankle dorsiflexion angles compared to the pre-training evaluations (22). There were also several studies that used trajectory tracking control to regulate the output and regulate the pulse width and pulse amplitude of the stimulation (23). The module was based on an adaptive fuzzy terminal sliding mode control and fuzzy logic control (FLC) to determine the stimulation output and force the ankle joint to track the reference trajectories. In their study, FES applied to TA was triggered before the heel-off event. Because the TA activation has been proven to occur after the heel-off event and the duration of the TA activation changed with the walking speed (24, 25), a time interval should be implemented after the heel-off event (26). In Thomas et al.’s study, the ankle angle trajectory of the paretic foot was modulated by an iterative learning control method to achieve the desired foot pitch angles (27). The non-linear relationship between the FES settings and the ankle angle influenced the responses of the ankle motion (28). FLC represents a promising technology to handle the non-linearity and uncertainty without the need for a mathematical model of the plant, which has been widely used in robotic control (29). Ibrahim et al. used FLC to regulate the stimulation intensity of the FES (30), and the same control was used on the regulation of the stimulation duration to obtain a maximum knee extension angle in Watanabe et al.’s study (31). However, most closed-loop controls adjust only one stimulation parameter, and few FES controls considered both varying the stimulation intensity and duration while accounting for the changing walking velocities.
In the present study, an intensity- and duration-adaptive FES was established, the FLC and a linear model were used to regulate the stimulation intensity and duration, respectively. The performance of the intensity- and duration-adaptive stimulation (IDAS) was compared with those of stimulation triggered by no stimulation (NS), heel-off stimulation (HOS), and speed-adaptive stimulation (SAS) for poststroke patients walking on a treadmill. The objective of this study is to find an appropriate FES control strategy to realize a more adaptive ankle joint motion for poststroke subjects.[…]
Functional electrical stimulation (FES) for patients with stroke and foot drop is an alternative to ankle foot orthoses. Characteristics of FES responders and non-responders have not been clarified.
1. To investigate the effects of treatment with FES on patients with stroke and foot drop. 2. To determine which factors may relate to responders and non-responders.
Multicenter, non-randomized, prospective study.
Multicenter clinical trial.
Participants, who experienced foot drop resulting from stroke, greater than 20 years old, and could provide consent to participate, were enrolled from hospitals between January 2013 and September 2015 and performed rehabilitation with FES.
Stroke Impairment Assessment Set Foot-Pat Test (SIAS-FP), Fugl-Meyer Assessment for Lower Extremity (FMA-LE), modified Ashworth scale (MAS) for ankle joint dorsiflexion and plantar flexion muscles, range of motion (ROM) for ankle joint, 10-m walking test (10mWT), timed up & go test (TUG), and 6-minute walking test (6MWT) were evaluated pre- and post-intervention. Age, sex, type of stroke, onset times of stroke, paretic side, Brunnstrom stage of the lower extremity (Br. stage-LE), functional independent measure (FIM), functional ambulation category (FAC), post-stroke months, number of interventions, total hours of interventions, and whether a brace was used were extracted from patients’ medical records and collected on the physiological examination day.
Main Outcome Measurements
We examined 10mWT and age, sex, type of stroke, onset times of stroke, paretic side, Br. stage-LE, FIM, FAC, post-stroke months, number of interventions, total hours of interventions, whether a brace was used, SIAS-FP, FMA-LE, MAS, ROM, TUG, and 6MWT before intervention. We divided participants into non-responders and responders with a change in 10mWT of <0.1 and ≧0.1 m/s, respectively. Single and multiple regression analyses were used for data analysis. Additionally, we compared the changes between groups.
Fifty-eight responders and 43 non-responders were enrolled. The between-group differences, compared for changes between pre- and post-intervention, were significant in terms of changes in SIAS-FP (P=.02), 10mWT (P<.001), 10-m gait steps (P<.001), TUG (P=.04), and 6MWT (P=.006). In the adjusted regression model, sex (OR, 3.92; 95% CI, 1.426–12.25; P=.007), number of interventions (OR, 1.028; 95% CI, 1.003–1.070; P=.03), and active ankle joint dorsiflexion ROM (OR, 1.047; 95% CI, 1.014–1.088; P=.005) remained significant.
The factors related to 10mWT showing changes beyond the minimally clinically important difference were found to be patient sex, number of interventions, and active ankle joint dorsiflexion ROM before intervention. When Patients with stroke who are greater active ankle joint ROM in female, use FES positively, they may benefit more from using FES.
Uzo Igwegbe, PT, MPT, fitting a stroke survivor with the thigh component of the Bioness L300 Go, targeted at stimulating the L hamstrings to minimize L knee hyperextension in stance during ambulation.
By Uzo Igwegbe, PT, MPT
Foot drop, a gait abnormality, is an insufficient ability to dorsiflex or clear the foot/feet during the swing phase of gait, causing an increased risk for stumbling, falls, or injury. In a normal gait cycle, initial foot contact occurs with the heel; however, an individual with foot drop may drag the foot and/or make initial contact with the forefoot or foot flat. To compensate they may excessively flex the hip and knee, or circumduct the affected limb, or increase time spent in swing phase of the affected extremity.
The cause of drop foot is due to damage to the common fibular (peroneal) nerve (inclusive of the sciatic nerve), weakness or paralysis of the tibialis anterior, extensor halluces longus and extensor digitorum longus. Foot drop is associated with cerebrovascular accident/stroke, brain injury, multiple sclerosis, cerebral palsy, spinal cord injury, spinal stenosis, disc herniation, poliomyelitis, diabetes mellitus, Charcot-Marie-Foot Disease, muscular dystrophy, Amyotrophic Lateral Sclerosis, or direct injury to the peroneal nerve.
Ankle foot orthotics (AFOs) and Functional Electric Stimulation (FES) technologies are used in the management and treatment of drop foot in physical therapy. These two approaches strive to facilitate a natural gait with increased speed, improved balance, confidence, safety, and independence with ambulation and functional mobility.
Product ResourcesThe following companies provide products to treat ankle injuries, foot drop and other aspects of stroke and neurological rehabilitation:
Ankle foot orthotics, the most common approach used, support neutral foot position to facilitate clearance during swing and provide ankle stability during loading response.1 AFOs are either off the shelf (for short-term use) or custom made from a cast (for complex cases or long-term use). These L-shaped braces are worn in footwear and, in most cases, a larger shoe size of one half to a full shoe size may be required due to the bulk of the orthosis. To obtain an AFO, a correct foot drop diagnosis by the therapist/physician and a physician’s AFO prescription is needed to proceed with a comprehensive assessment, with recommendations of treatment options from a licensed orthotist. A cast impression of the foot and leg is done for custom AFO. Follow-up appointments are done after reception of the AFO for re-evaluation of fit and function. The AFOs prescribed for drop foot include:
1) Posterior Leaf Spring AFO:This prefabricated, semi-rigid, polypropylene AFO supports individuals with mild foot drop and knee instability. It provides dorsiflexion during swing and controls plantarflexion at heel strike. Resistance to plantarflexion can be controlled by modifying the ankle and footplate trim lines. This AFO is the initial “go-to” brace for physical therapists because they are readily available, lightweight, inexpensive, and can provide initial ankle stability early in rehabilitation; however, there are newer, lighter, more comfortable, user-friendly and functional models available. Sources for these types of AFOs include Orthotic & Prosthetic Lab Inc, Webster Groves, Mo, which makes the Dynamic ROM AFO, and Orange County, Calif-headquartered, Össur Americas, which offers a prefabricated, polypropylene AFO Leaf Spring.
2) Solid AFO: This custom-fabricated plastic AFO prevents plantarflexion and prevents/limits dorsiflexion. It supports the ankle-foot complex in the coronal and sagittal planes in individuals with complete or nearly complete loss of dorsiflexion and mild to moderate knee hyperextension. Although bulky, it provides significant ankle support. It is contraindicated in individuals with fluctuating edema due to its rigid structure. Its bulk, difficulty obtaining properly fitted footwear, and general discomfort due to heat generated from continuous use can be barriers to utilization. One source for these devices is Kiser’s Orthotic and Prosthetic Services Inc, Keene, NH, which manufactures its solid ankle AFO to help combat spasticity, help the toe to clear, and prevent the Achilles tendon from tightening.
3) Free Motion Articulating AFO: The ankle joint here is activated, so the individual must have active ankle motion. It is commonly prescribed for individuals with some dorsiflexion, but who still need frontal plane stability. It is not recommended for patients with significant quadriceps weakness. Among the products available in this category is the Exos Free Motion Ankle from DJO Global Inc, Vista, Calif; a prefabricated AFO made to be moldable, adjustable, and can be custom fit. Becker Orthopedic, Troy, Mich, also offers a plastic AFO with articulating ankle, which can be used with a variety of the company’s thermoplastic ankle joints and posterior stops.
4) Short Leg AFO with Fixed Hinge: A good option for people who have flatfoot and drop foot, this AFO holds the foot at 90 degrees to the lower leg and controls unwanted inward rotation of the foot, which is common in stroke and Charcot-Marie Tooth patients. It is relatively light and easily fits footwear. A disadvantage of this brace, and the solid AFO, is its failure to provide a natural gait. Among the sources that offer this type of orthoses is New Linox, Ill-headquartered Rinella Orthotics & Prosthetics Inc.
5) Dorsiflexion Assist AFO: This has a spring-like hinge which assists the ankle with dorsiflexion as the foot comes off the ground for those with mild to moderate drop foot, and a flat or unstable foot as it offers a more natural gait pattern. The short lower leg length of this brace and the Short Leg AFO fails to provide adequate support in people over 6 feet or 225 pounds.
6) Plantarflexion Stop AFO: This brace prevents plantarflexion and has a hinge that facilitates normal dorsiflexion. Due to its cumbersome size, it is not utilized often but can be effective in people with more severe or spastic drop foot. Orthotic & Prosthetic Lab Inc provides plantarflexion stop AFOs that are designed to prevent unwanted plantarflexion while permitting free dorsiflexion. These AFOs are also available from Yakima, Wash-headquartered Yakima Orthotics & Prosthetics, and are designed to provide medial/lateral stability and plantarflexion/dorsiflexion control.
7) Energy Return AFO: This prefabricated, lightweight AFO is made of carbon graphite material. It provides assistance in dorsiflexion and energy return at push-off to propel the individual forward with plantarflexors. It provides stability only in the sagittal plane; however, a foot orthotic can be placed on the flat foot for frontal plane stability. In stroke and spina bifida patients, carbon-fiber AFOs increased walking speed and decreased energy cost when compared to unbraced walking.2 Research suggests that Energy Return AFOs facilitate plantar flexor muscle regeneration and prevents atrophy.3,4
Therapists have a number of choices in this category, including the ToeOff carbon composite dynamic response floor reaction AFO from Allard USA Inc, Rockaway, NJ; designed to keep the foot up during swing phase as well as provide soft heel strike and stability in stance. In addition to providing good toe-off to the wearer, the company recommends this AFO for foot drop in combination with no spasticity to moderate spasticity. The Ypsilon, also from Allard, is made to provide toe-off assistance to stable ankles while also allowing natural ankle movement, while the company’s BlueROCKER provides more rigid orthopedic control and was developed for bilateral foot drop. It can be used for foot drop in combination with no spasticity to severe spasticity, as well as partial foot amputations, impaired balance, and weakness or impairment in multiple leg muscle groups. The Peromax carbon fiber AFO and Trulife Matrix Max carbon fiber AFO are two other options available to the PT market in this category.
Users with big toe plantar ulcerations who are unable to cope with the plastic AFO due to skin breakdown from continuous pushing off the foot plate can have the addition of a custom foot orthotic, which can help offload those areas. Items like a heel lift can be placed under the foot plate to control for knee hyperextension. Despite their advantages, this AFO is not ideal for individuals with large calves or very tall individuals, as their long stride repeatedly overextend and weaken the AFO, or individuals with spastic drop foot or tight Achilles tendon, as the overactivity of the muscle pushes down on the foot plate, excessively hyperextending the knee.
Therapist is shown fitting a stroke survivor with the lower leg cuff of the Bioness L300 Go to stimulate the tibialis anterior muscle to improve L foot clearance during ambulation.
Performing the initial stimulation testing to determine whether the desired muscle activation is elicited prior to ambulation.
Functional Electrical Stimulation Management
The L300 Foot Drop System and WalkAide are approved medical devices for foot drop by the US Food and Drug Administration and are used in rehabilitation hospitals. The Bioness Legacy L300, L300 Go, and WalkAide consist of a lower leg cuff which holds electrode(s), providing low-level electrical stimulation to an intact peroneal nerve. The L300 Go and WalkAide use advance tilt sensor technology to monitor movement in all three kinematic planes, providing stimulation to lift the foot at the appropriate time. This makes foot clearance at various cadence and terrains feasible. They do not require a foot sensor like the Legacy L300, decreasing setup time and allowing users to ambulate with or without footwear. They can be used if knee instability and foot drop are present, promoting clinical application as majority of individuals present with both. Patients work alongside a clinician to obtain training for home use or utilize these technologies in the clinical setting.
The options available in the treatment and management of foot drop are numerous. The path to obtaining the right product involves a joint partnership between the patient, physical therapist, physician, and orthotist. The clinician must draw from the patient’s needs, abilities, facets of gait needing improvement, and special conditions specific to the patient to recommend the optimal product. In the choice between an AFO and FES device, the ultimate goal is to provide a product that will yield compliance, a normalized gait, and contribute to independent function. PTP
Uzo Igwegbe, PT, MPT, is outpatient physical therapist, senior, at HealthSouth Rehabilitation Hospital of Cypress, located in Houston, Texas. She earned her master’s degree in physical therapy at The Robert Gordon University in Aberdeen, Scotland, in February 2010. She joined HealthSouth Rehabilitation Hospital in January 2012, starting at the City View location in Fort Worth, Texas, working in both inpatient and outpatient settings, developing treatment plans for pulmonary, brain injury and orthopedics patients. Igwegbe joined the HealthSouth Cypress team in September 2013, where she primarily worked with outpatients with a wide range of neuromuscular and musculoskeletal conditions, as well as post-orthopedic surgery patients. For more information, contact PTPEditor@medqor.com.
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BACKGROUND:Foot drop is common gait impairment after stroke. Functional electrical stimulation (FES) of the ankle dorsiflexor muscles during the swing phase of gait can help correcting foot drop.
OBJECTIVE:To evaluate efficacy of additional novel FES system to conventional therapy in facilitating motor recovery in the lower extremities and improving walking ability after stroke.
METHODS:Sixteen stroke patients were randomly allocated to the FES group (FES therapy plus conventional rehabilitation program) (n = 8), and control group (conventional rehabilitation program) n = 8. FES was delivered for 30 min during gait to induce ankle plantar and dorsiflexion. Main outcome measures: gait speed using 10 Meter Walk Test (10 MWT), Fugl-Meyer Assessment (FMA), Berg Balance Scale (BBS) and modified Barthel Index (MBI).
RESULTS:Results showed a significant increase in gait speed in FES group (p < 0.001), higher than the minimal detected change. The FES group showed improvement in functional independence in the activities of daily living, motor recovery and gait performance.
CONCLUSIONS:The findings suggest that novel FES therapy combined with conventional rehabilitation is more effective on walking speed, mobility of the lower extremity, balance disability and activities of daily living compared to a conventional rehabilitation program only.
To compare virtual reality (VR) combined with functional electrical stimulation (FES) to cyclic FES for improving upper extremity function and health-related quality of life in patients with a chronic stroke.
A pilot, randomized, single blinded, controlled trial.
Stroke rehabilitation inpatient unit
Forty-eight participants with a hemiplegia secondary to a unilateral stroke for >3 months, with a hemiplegic wrist extensor Medical Research Council (MRC) scale score of 1–3.
FES was applied to the wrist extensors and finger extensors. A virtual-reality(VR) based wearable rehabilitation device was used, combined with FES and virtual activity-based training. The control group received cyclic FES only. Both groups completed 20 sessions, over a 4-week period.
Main outcome measures
Primary outcomes were the change in the Fugl–Meyer Assessment: upper extremity (FMA) and Wolf Motor Function Test (WMFT) scores. Secondary outcomes were the change in the Box and Block test (BB), Jebsen Taylor Hand Function Test (JTT), and Stroke Impact Scale (SIS) scores. Assessments were performed at baseline (T0) and at 2 weeks (T1), 4 weeks (T4), and 8 weeks (T8). Between-group comparisons were evaluated using a repeated measures analysis of variance.
Forty-one participants were included in the analysis. Compared to FES alone, VR-FES produced greater increase in FMA–distal score (p=0.011) and marginal improvement in JTT–gross score (p=0.057). VR-FES produced greater, although non-significant, improvements in all other outcome measures, except in the SIS–ADL/IADL score.
FES with VR-based rehabilitation may be more effective than cyclic FES to improve distal gross upper extremity function post-stroke.