Ankle dorsiflexor weakness (paresis) is one of the most frequently persisting consequences of stroke. The purpose of this exploratory study is to compare two different treatments -- Contralaterally Controlled Neuromuscular Electrical Stimulation (CCNMES) and Cyclic Neuromuscular Electrical Stimulation (cNMES) -- for improved recovery of ankle movement and better walking after stroke.
Ankle dorsiflexor weakness results in inefficient and unstable gait. While routine physical therapy is beneficial, for many individuals it remains limited in its effectiveness, and consequently many stroke survivors have difficulty walking safely or remain non-ambulatory. Ankle-foot-orthoses (AFOs) are often prescribed to provide ankle stability, but because they limit ankle mobility they may actually inhibit recovery of dorsiflexion. Advanced rehabilitation techniques that emphasize active, repetitive, goal-oriented movement of the impaired limb have produced measurable functional improvements, yet a significant degree of lower extremity disability often remains. In addition, some of these emerging therapies are difficult to administer and are applicable only to patients who retain at least some degree of ambulation. Thus, there is a need for alternative treatments.
This is an exploratory study of an innovative neuromuscular electrical stimulation (NMES) treatment for restoring lower extremity motor control following stroke. We will investigate whether stroke survivors with chronic footdrop recover voluntary ankle dorsiflexion after a novel treatment of NMES. Surface electrodes will deliver stimulation to dorsiflex the ankle with an intensity that is proportional to the amount of dorsiflexion of the other unimpaired ankle. Thus, voluntary dorsiflexion of the unaffected ankle produces stimulated dorsiflexion of the affected ankle. We refer to this stimulation paradigm as Contralaterally Controlled Neuromuscular Electrical Stimulation (CCNMES). In contrast to existing peroneal nerve stimulators, CCNMES is not intended to be used to assist ambulation; rather it is intended as solely a motor retraining paradigm that may reduce lower extremity impairment and improve ambulation. The primary objective of the proposed study is to obtain pilot data so that an estimate can be made of the efficacy of CCNMES in reducing lower extremity impairment and improving ambulation.
Twenty-six chronic stroke survivors (>6 months post-stroke) will be randomized to either CCNMES or cyclic NMES, an intervention that provides electrical stimulation of the ankle dorsiflexors, but with preprogrammed timing and intensity. For both groups, the treatment will last 6 weeks. Assessments of ankle impairment and ambulation will be made at baseline and at end of treatment.
This study is the first randomized controlled trial of CCNMES for restoring ankle dorsiflexion in patients with chronic hemiplegia.
- Electrical stimulator Device
Intervention Desc: 6-week intervention 15 minutes of therapist-guided stimulated ankle exercise + 30 minutes of physical therapy in the laboratory twice a week. Self-administered active repetitive ankle dorsiflexion exercise performed twice a day, 6 days a week at home using the device. ARM 1: Kind: Experimental Label: CCNMES Description: Contralaterally Controlled Neuromuscular Electrical Stimulation ARM 2: Kind: Experimental Label: Cyclic NMES Description: Cyclic Neuromuscular Electrical Stimulation
- Allocation: Randomized
- Masking: Single Blind (Outcomes Assessor)
- Purpose: Treatment
- Endpoint: Efficacy Study
- Intervention: Parallel Assignment
|Type||Measure||Time Frame||Safety Issue|
|Primary||Active Range of Motion of Ankle. Maximum voluntary ankle dorsiflexion angle will be measured using an electrogoniometer. Three ankle dorsiflexion trials will be averaged.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Ankle Movement Tracking Error. The subject's task is to try to keep a computer cursor on or as close to a scrolling trace as possible by voluntarily dorsiflexing the ankle. Three to six trials will be administered after a practice trial.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Maximum Voluntary Ankle Dorsiflexion Isometric Moment. Isometric ankle dorsiflexion moment will be measured. Three isometric moment trials will be averaged.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Fugl-Meyer Lower Extremity Motor Assessment. In the lower limb motor impairment component of the Fugl-Meyer Assessment (FMA), the subject is asked to make various isolated and simultaneous movements of the hip, knee, and ankle.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Quantitative Gait Analysis. Gait kinematics and spatio-temporal gait parameters will be assessed using a motion capture and analysis system.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Modified Emory Functional Ambulation Profile (MEFAP). The MEFAP is a measure of functional ambulation, measuring the time to ambulate through 5 common environmental terrains.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Secondary||Questionnaire. A questionnaire will be administered to assess the participants' impression of the intervention's dose and ease of using the device, as well as of their ability to dorsiflex their ankle and of any effect on their walking.||Pre-treatment, End of treatment, 4-wks & 12-wks Post-treatment.||No|
|Primary||Change in Lower Extremity Fugl-Meyer Score at End of Treatment||2 timepoints: Prior to treatment, and End of treatment at 6 weeks.|
|Primary||Change in Gait Velocity (cm/Sec) at End of Treatment||2 timepoints: Prior to treatment, and End of treatment at 6 weeks.|
|Primary||Change in Time (Sec) to Complete the Modified Emory Functional Ambulation Profile (MEFAP).||2 timepoints: Prior to treatment, and End of treatment at 6 weeks.|