Posts Tagged drop foot
[Abstract] Restoring mobility after stroke: first kinematic results from a pilot study with a hybrid drop foot stimulator (with References)
The objective was to obtain first insights into the kinematic and kinetic walking patterns resulting from an implanted functional electrical stimulation system in subjects with a drop foot caused by stroke.
Four subjects who experienced a stroke were chosen due to a comparatively long/short time after surgery and young/old at the stroke event were examined retrospectively with gait analysis. Kinematics and kinetics of normal walking were assessed in comparison with and without activated drop foot stimulation.
In general, an improvement regarding spatiotemporal parameters as a result of the stimulation could be observed. Walking speed was increased by 45 % and stride length by 22 % after a mean usage of 7 (2–14) months, whereas both younger subjects improved significantly more. Dorsiflexion increased in all subjects on average from 1.3° to 11.6° during initial contact as well as from 11.3° to 17.0° during mid-swing and therefore implies an advantage of around 5.5 inch foot clearance. Pathologic elements like knee hyperextension during loading response and mid-stance, leg circumduction during swing or the increased hip flexion of the contralateral leg during mid-stance could be in general adjusted with stimulation.
An implantable functional electrical stimulation system seems to be a promising treatment of drop feet following strokes. Further clinical investigations are necessary to confirm these first insights.
[Abstract] Thesis (Doctoral). A quantitative and qualitative exploration of changes in walking post-stroke and the impact of functional electrical stimulation for correction of dropped foot.
The research presented in this thesis explores changes in walking following a stroke, empirically at a group level and from the perspective of the individual. Walking does not appear to have been previously been systematically explored from the perspective of the individual stroke survivor. In the first phase of this research, quantitative methods were used to investigate existing gait rehabilitation interventions applied in a novel population. Problems with ‘dropped foot’ post-stroke are common and can result in trips, falls and restricted mobility. Electrical stimulation of the common peroneal nerve produces dorsiflexion and eversion to correct dropped foot and is associated with improved motor control and walking post-stroke, however most research studies have recruited people with chronic stroke to reduce sample variability. People who are less than six months post-stroke may gain added benefit from electrical stimulation as poor walking patterns may not yet have become habitual and the potential for motor recovery due to cortical reorganisation is greatest. A pilot parallel group partially single blinded randomised controlled clinical trial (n=20) identified statistically significant within group differences in mobility after the intervention period in both groups (maintained during follow-up). No statistically significant between group differences were observed apart from gait quality, which was slightly better in the intervention group. Participants in the intervention group also walked faster when stimulation was used than without it. The protocol was feasible and 144 participants per group would produce an adequately powered definitive study. Participants in the pilot clinical trial spoke about valued personal aspects of walking but these were not fully captured by the outcome measures and are not reflected in the published literature. To systematically explore changes in walking post-stroke in depth interviews with a subgroup of the original participants were undertaken using an interpretative phenomenological approach (n=4). The participants gave examples of post-stroke walking related changes in their self-perception, roles and their embodied experience of walking that are rarely mentioned in the rehabilitation literature, apart from in personal accounts written by people living with chronic illness. They spoke about walking within the context of activities that they identified as personally important. These participants valued being able to walk distances at a reasonable speed, being independent, safe and confident. They said that they missed their pre-stroke spontaneity, freedom, agility and their lost automatic body movement, which are not usually assessed in stroke rehabilitation research or reflected in published research. Areas for further work have been identified.
Download. (Login required)
Restricted to System admin until 31 October 2017.
[Abstract] Evaluation of the Efficacy and Robustness of a Second Generation Implantable Stimulator in a Patient With Hemiplegia During 20 Years of Functional Electrical Stimulation of the Common Peroneal Nerve.
We evaluated the efficacy and robustness of a second generation implantable stimulator for correcting drop foot (DF) in a patient with left-sided hemiplegia over 20 years of functional electrical stimulation (FES) of the common peroneal nerve (CPN). Dorsal flexion and eversion of the affected foot was partially restored by FES of the superficial region of the CPN innervating mostly the tibialis anterior (TA) and partly peroneus longus (PL) and peroneus brevis (PB) muscles. The reasons for implant failure during the long-term follow-up assessment were analyzed and resolving procedures were identified. The stimulator had an average failure rate of once every three years, due to repetitive mechanical load on the lead wires of its internal and/or external unit, and had to be serviced once per year to replace the heel switch integrated into the shoe sole. FES-associated mechanical trauma to the CPN elicited a thickening of the connective tissue around the CPN and a slightly compromised conduction velocity of the CPN. FES of the CPN, with the second generation implantable stimulator, improved gait parameters of the affected leg during the 20 years period. Long-term, daily FES enables a functional and reliable recruitment of nerve fibers, thus providing a sufficient dorsal flexion and optimal eversion of the affected foot to sustain unassisted, almost normal gait. Therefore, the presented implant is suitable for very long-term FES of the CPN.
Source: Evaluation of the Efficacy and Robustness of a Second Generation Implantable Stimulator in a Patient With Hemiplegia During 20 Years of Functional Electrical Stimulation of the Common Peroneal Nerve – Pečlin – 2016 – Artificial Organs – Wiley Online Library
[ARTICLE] Effectiveness of Single Functional Electrical Stimulation in Neurological Patients with Ankle-Foot Orthoses – Full Text PDF
Background: Drop foot is a distal deficiency common in patients with central nervous system diseases that makes clearance difficult during swing phase, contributes to inefficient gait compensations, contributes to increase incidence of falls and energy expenditure. Aim of this study is to evaluate the effectiveness of a single application of functional electrical stimulation compared with ankle-foot orthoses in patients with drop foot.
Methods: Patients enrolled were unable to walk and to perform test without ankle-foot orthoses. They were evaluated by 10-meters walk test, obstacles test, up-and-down stair test, six-minute walk test and gait analysis with inertial sensors. All tests were performed with ankle-foot orthoses and with no ankle-foot orthoses and application of single functional electrical stimulation.
Results: Thirteen patients (8 males and 5 females) were recruited for this study out of 41 potential subjects. Data collected were processed by Student’s t test and by Wilcoxon test for paired observations and by Student’s t test and Mann-Whitney test for independent samples. P ≤ 0.05 were considered significant. For each test suitable effect sizes (Cohen’s d, and Pearson’s r) were calculated. Analysis of results with ankle-foot orthoses and with no anklefoot orthoses and application of single functional electrical stimulation showed no statistically significant difference in all test.
Conclusions: The use of single functional electrical stimulation showed same effects of ankle-foot orthoses on walking capacity and motor performance in chronic neurological diseases. More studies would be required to assess the long term effectiveness of functional electrical stimulation and to evaluate if its application in acute-phase may be used in association with traditional treatment.
[ARTICLE] New therapeutic option for drop foot with the ActiGait peroneal nerve stimulator – A technical note
- -Drop foot due to a peripheral nerve injury should be excluded before surgery
- -Exact planning of implants’ position ensures a comfortable handling of the device
- -Strainless implantation of the cable to avoid nerve injury due to tug at the nerve
A drop foot occurs in up to 20% of stroke patients and leads to an increased risk of falls. Until recently, only a foot orthosis or surface stimulation were able to improve the gait of these patients. Recent studies have shown that direct peroneal nerve stimulation with an implantable four-channel peroneal nerve stimulator (ActiGait) allows independent electrode adjustment and leads to better functional results and an improved quality of life. The application of this therapeutic option is restricted to patients with a drop foot attributable to a lesion of the first motor neuron caused by stroke, multiple sclerosis or tumors.In this paper, we present the first technical note with possible pitfalls of the surgical procedure and the perioperative care after implantation of ActiGait drop foot stimulators in 50 patients.
Composite material advances over the past 10 years have improved the design creativity and possibility for clinical orthotists worldwide. In the past, an ankle orthosis required a completely solid and fully encompassing design in order to attain the mechanical control, durability and ultimately the function needed for corrective ankle varus bracing. These devices were essentially plastic shells that created a solid/static environment which was safer than not using a brace at all, but they were also highly problematic with patients complaining of pressure points and a clunky gait. Today we can simulate more natural gait patterns while completely avoiding pressure points.
Controlling the Tri-Planar Deformities
Kinetic Research offers a variety of ankle braces, each with its own character and effect to meet the needs of the user, from the most basic needs to the most complex. For folks that have foot/ankle weakness but have good alignment of their ankle, we offer the Noodle line of AFOs. These are the most dynamic and least restrictive designs for controlling drop foot. When the user has a tight heel cord with mild supination or ankle varus, they become a candidate for a PLS design. When the user has more significant ankle varus he/she becomes a candidate for the ValgaNoodle AFO. The ValgaNoodle offers the highest degree of lateral control that we can provide. It’s important to have a team approach when choosing the type of AFO that will work best for your individual needs, and there is always a trade off between control and mobility. The team is made up of the patient, the orthotist and the physician/therapist, and all have to be involved for the best results. The objective is to “put on as little as possible, but get the job done”.
Improving Stability During Gait
The ValgaNoodle is made specifically for varus control. It’s a highly custom AFO, meaning. That it is not assembled using pre-made components. The creation of a ValgaNoodle begins with a highly skilled orthotist who will evaluate and cast for the device. That attending orthotist will manipulate and control the patient’s foot while he is casting, keeping the ankle in the best position possible to maximize the effect of the finished ValgaNoodle. Evaluations and observations made by the clinical orthotist are then incorporated into a design formulation that will work best for the individual patient. The design details are then determined based on the level of control vs free movement that is needed to maximize the performance of the user. One of the objectives is to keep the ValgaNoodle lightweight and as simple to use as possible. The orthotist will select the device based on the severity of the case, as well as the users lifestyle, activities and footwear.
Fitting the Device
The one common mechanical concept for the ValgaNoodle variations of AFOs is, that they will all have a single medial strut with a floating lateral “reverse T” cuff.
Design options for the footplate:
- Flat, in which we match the bottom of the shoe. When we make it in this format, it will usually have a custom foam removable arch support. It offers the least control but because it’s flat, we can make it flexible.
- Contoured. This is similar to a UCBL footplate. Our technicians will adjust the cast taken by your orthotist to increase lateral control in a compact way for easy shoe selection.
- Contoured with high control. This system goes higher than the UCBL, encompassing the dorsum of the foot, and has a special 3-point strapping system to provide maximum control.
Design options for the strut:
- Solid ankle, the highest level of control, removing the user’s ability to dorsi/plantar flex.
- Dynamic, which allows dorsi/plantar flexion, but with reduced lateral control.
Design options for the cuff:
- Posterior, for a normal or hyperextended knee.
- Anterior, generally used for knee extension weakness. Easier to don, but limited to low top shoes.
Tina Mann on the Early Show 07/22/09. The Miracle in a Box that changed Tina Mann’s life.
…“This study demonstrates that subjects with chronic stroke can achieve a meaningful improvement in the speed of their ambulation with functional electrical stimulation therapy. Moreover at 42 weeks the subjects in this study walked faster with and without the device indicating a therapeutic effect that can be sustained over time.”…