Hip flexor fatigue limits walking in CMT

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Muscle Nerve. 2009 Apr 29.

Hip flexor fatigue limits walking in Charcot-Marie-Tooth disease.

Ramdharry GM, Day BL, Reilly MM, Marsden JF.

St. 's School of Physiotherapy Kingston University, London, UK.

Charcot-Marie-Tooth (CMT) disease results in distal lower limb weakness that

affects walking. In this study we assess the role of the hip flexors in

compensating for distal weakness while walking and the effects of prolonged

walking on these putative compensatory strategies.

Eighteen subjects with CMT disease were compared with 14 matched controls while

they walked on a treadmill to a predetermined point of perceived effort. A

significant reduction was observed in peak hip flexor velocity during walking

and hip flexor maximal voluntary contraction. In a second session following

selective fatigue of the hip flexors, hip flexor velocity decreased immediately

on walking, and walking duration was greatly reduced.

This study suggests that hip flexors compensate for distal weakness and that

fatigue in the hip flexors can limit walking duration. Treatments directed

toward improving proximal muscle strength may therefore help to delay onset of

hip flexor fatigue and thus prolong walking duration.