Stimulation of shank muscles during functional electrical stimulation cycling increases ankle excursion in individuals with spinal cord injury.
OBJECTIVE
To investigate the effect of shank muscle stimulation on ankle joint excursion during passive and functional electrical stimulation (FES) leg cycling.


METHODS
Within-subject comparisons.


METHODS
Laboratory setting.


METHODS
Well-trained FES cyclists (N=7) with chronic spinal cord injuries.


METHODS
Two experimental sessions were performed on an isokinetic FES cycle ergometer with a pedal boot that allowed the ankle to plantarflex and dorsiflex during cycling. During the first session, the optimal stimulation timings to induce plantarflexion and dorsiflexion were investigated by systematically altering the stimulation angles of the shank muscles (tibialis anterior [TA] and triceps surae [TS]). During the second session, TA and TS stimulation was included with standard FES cycling (quadriceps, hamstrings, and gluteals) for 6 subjects.


METHODS
Ankle, knee, and hip movements were analyzed using 2-dimensional video.


RESULTS
The ankle excursions during passive cycling were 19°±6°. TA and TS stimulation increased ankle joint excursion up to 33°±10° and 27°±7°, respectively. Compared with passive cycling, ankle joint excursion was not significantly increased during standard FES cycling (24°±7°). TA and TS stimulation significantly increased the ankle excursion when applied during standard FES cycling (41°±4°).


CONCLUSIONS
Freeing the ankle joint to rotate during FES cycling was found to be safe. The combination of shank muscle stimulation and repetitive ankle joint movement may be beneficial for improving ankle flexibility and leg conditioning. Further research is required to test and design ankle supports that might maximize the benefits of shank muscle activation.
Clinical Exercise and Rehabilitation Unit, Exercise Health and Performance Research Group, The University of Sydney, Sydney, Australia. Che.Fornusek@Sydney.edu.au
Ché
C
Fornusek
Glen M
GM
Davis
Ilhun
I
Baek
D000843:Ankle Joint; D001642:Bicycling; D001696:Biomechanical Phenomena; D004599:Electric Stimulation Therapy / Q000379:methods*; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000503:physiopathology; D010264:Paraplegia / Q000209:etiology / Q000534:rehabilitation*; D013119:Spinal Cord Injuries / Q000150:complications / Q000534:rehabilitation*