Altered contractile properties of the quadriceps muscle in people with spinal cord injury following functional electrical stimulated cycle training.
METHODS
A longitudinal training study.


OBJECTIVE
To assess if contractile speed and fatigability of paralysed quadriceps muscles in individuals with spinal cord injury (SCI) can be altered by functional electrical stimulation leg cycle ergometry (FES-LCE) training.


METHODS
The Sint Maartenskliniek rehabilitation centre and the University of Nijmegen, Nijmegen, the Netherlands.


METHODS
Contractile properties of the quadriceps muscle were studied in seven people with motor-complete SCI who participated in a FES-LCE training program. Subjects trained for 30 min, three times per week for 6 weeks. Contractile speed and fatigue characteristics of electrically stimulated isometric contractions were compared before and after 6 weeks of FES-LCE.


RESULTS
Fatigue resistance improved following FES-LCE training as indicated by the higher forces maintained in response to repetitive electrical stimulation. In contrast with an improved fatigue resistance, the maximal rate of force rise was unaffected, the speed of relaxation increased and the fusion of a 10 Hz force signal decreased. Furthermore, the force-frequency relationship shifted to the right at low stimulation frequencies, indicated by a decline in the ratio of 1 and 100 Hz force responses as well as the ratio of 10 and 100 Hz force responses.


CONCLUSIONS
FES-LCE training can change the physiological properties of the quadriceps muscle in people with SCI. Even after a short period of training, the stimulated muscles become more resistant to fatigue. Furthermore, the increased speed of relaxation and associated decreased fusion and altered force-frequency relationship following training may be related to adaptations in the calcium handling processes, which reflect an early response of long-term disused muscles.
Gerrits
H L
HL
Institute for Fundamental and Clinical Human Movement Sciences, Vrije University Amsterdam, The Netherlands.
de Haan
A
A
Sargeant
A J
AJ
Dallmeijer
A
A
Hopman
M T
MT
D000328:Adult; D004558:Electric Stimulation / Q000379:methods; D005080:Exercise Test; D005081:Exercise Therapy; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011930:Reaction Time; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation* / Q000628:therapy*; D016896:Treatment Outcome