A novel neuromuscular electrical stimulation treatment for recovery of ankle dorsiflexion in chronic hemiplegia: a case series pilot study

Abstract

Objective: To evaluate the feasibility of improving active ankle dorsiflexion with contralaterally controlled neuromuscular electrical stimulation (CCNMES).

Design: CCNMES dorsiflexes the paretic ankle with a stimulation intensity that is directly proportional to the degree of voluntary dorsiflexion of the unimpaired contralateral ankle, which is detected by an instrumented sock. Three subjects with chronic (>6-mo poststroke) dorsiflexor paresis participated in a 6-wk CCNMES treatment, which consisted of self-administering CCNMES-assisted ankle dorsiflexion exercises at home daily and practicing an ankle motor control task in the research laboratory twice a week.

Results: For subjects 1 and 2, respectively, maximum voluntary ankle dorsiflexion increased by 13 and 17 degrees, ankle movement tracking error decreased by approximately 57% and 57%, and lower limb Fugl-Meyer score (maximum score is 34) increased by 4 and 5 points. Subject 3 had no appreciable improvement in these measures. Both subjects 1 and 2 maintained their performance in ankle movement tracking through the 3-mo follow-up; subject 2 also maintained the gains in maximum ankle dorsiflexion and Fugl-Meyer score.

Conclusions: These results suggest that CCNMES may have a positive effect on ankle motor impairment in some stroke survivors. Further investigation of the effect of CCNMES on gait is warranted.

Conflict of interest statement

Disclosures:

Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.

Figures

FIGURE 1

Contralaterally controlled neuromuscular electrical stimulation (CCNMES) system. Volitional dorsiflexion of the unaffected ankle produces a proportional intensity of stimulation to the paretic ankle dorsiflexors.

FIGURE 2

Maximum voluntary ankle dorsiflexion angle. Data points at baseline are the average values from four baseline assessment sessions. DF, dorsiflexion; B, baseline; EOT, end of treatment.

FIGURE 3

Sample trials of ankle movement tracking assessment for subject 2. Vertical axis represents the subject’s ankle range of motion achieved that day, such that 100% corresponds to maximum voluntary dorsiflexion and 0% corresponds to ankle resting angle. Error indicated is for that particular trial.