Isokinetic plantar flexor performance and fatiguability in peripheral arterial insufficiency. Effects of training vs....

Seventeen men with peripheral arterial insufficiency and intermittent claudication (maximum walking tolerance less than 1000 m) underwent a bypass operation (group A, n = 8) or carried out simple exercises (repeated heel-raising) at home (group B, n = 9). The effects of treatment on the isokinetic performance of the plantar flexors and on fatiguability were assessed. Before treatment both groups had similarly low Doppler pressure indices, maximum performance and fatiguability level. Maximum walking tolerance was increased by treatment in both groups. Maximum plantar flexor output rose in group A, partly due to increased range of motion, but was only slightly changed in group B. Bypass surgery also led to increased electrical efficacy (contractional work/integrated electromyogram). Plantar flexor fatiguability normalized in six of the eight group A men, but in only a few from group B. Improvement in group B may be explained by specific adaptation of (mainly type 2B) muscle fibres. After bypass the increased capacity to remove combustion products may be the major reason for normalized fatiguability. Bypass surgery is preferable for most cases of intermittent claudication.