Stroke-related effects on maximal dynamic hip flexor fatigability and functional implications.
BACKGROUND
Stroke-related changes in maximal dynamic hip flexor muscle fatigability may be more relevant functionally than isometric hip flexor fatigability.


METHODS
Ten chronic stroke survivors performed 5 sets of 30 hip flexion maximal dynamic voluntary contractions (MDVC). A maximal isometric voluntary contraction (MIVC) was performed before and after completion of the dynamic contractions. Both the paretic and nonparetic legs were tested.


RESULTS
Reduction in hip flexion MDVC torque in the paretic leg (44.7%) was larger than the nonparetic leg (31.7%). The paretic leg had a larger reduction in rectus femoris EMG (28.9%) between the first and last set of MDVCs than the nonparetic leg (7.4%). Reduction in paretic leg MDVC torque was correlated with self-selected walking speed (r2=0.43), while reduction in MIVC torque was not (r2=0.11).


CONCLUSIONS
Reductions in maximal dynamic torque of paretic hip flexors may be a better predictor of walking function than reductions in maximal isometric contractions.
Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, USA.
Henry R
HR
Kuhnen
Megan M
MM
Rybar
Tanya
T
Onushko
Ryan E
RE
Doyel
Sandra K
SK
Hunter
Brian D
BD
Schmit
Allison S
AS
Hyngstrom
D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D020521:Stroke / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*
dynamic contractions; hip flexors; neuromuscular fatigue; stroke; walking