Hemodynamic effects of supervised calf muscle exercise in patients with venous leg ulceration: a prospective controlled study

Abstract

Hypothesis: Because more than two thirds of patients with venous ulcer have an impaired calf muscle pump, enhancement of its ejecting ability with physical training may generate an improved hemodynamic milieu sufficient to promoting ulcer healing. This study evaluated the effects of short-term supervised calf exercise on calf muscle pump function and venous hemodynamics in limbs with venous ulceration.

Design: Prospective controlled study.

Settings: University-associated tertiary care hospital.

Patients: The study consisted of 2 groups. An exercise group comprised 10 patients (median age, 72 years) receiving supervised isotonic calf muscle exercise for 7 consecutive days. A control group comprised 11 patients matched with those in the exercise group for age, sex, ulcer size, and ulcer duration (all, P>.09). Patients in both groups had perimalleolar venous leg ulcers, impaired calf muscle function (ejection fraction, <60%), and full ankle joint movement.

Interventions: After providing a complete clinical history, both groups underwent a physical examination, venous duplex scanning, and air plethysmography. The venous filling index, venous volume, residual venous volume, and residual volume fraction of the calf on standing were measured plethysmographically at baseline and on day 8, in addition to calf muscle endurance as determined by the maximal number of plantar flexions performed against a fixed 4-kg resistance during 6 minutes (1 flexion/s). Operators were blinded to the subject's group. Exercise in the first group entailed consecutive active plantar flexions using a standardized 4-kg resistance pedal ergometer. Subjects daily completed 3 sets of flexions of 6 minutes each. All patients had short-stretched compression bandaging.

Main outcome measures: The ejected venous volume and ejection fraction were evaluated in both groups at baseline and on day 8.

Results: Both groups had a similar hemodynamic performance at baseline for all the variables evaluated (P>.10). After 7 days of exercise, patients in the exercise group improved their ejected venous volume by 67.5%, ejection fraction by 62.5%, residual venous volume by 25% (all 3, P =.006), and their residual volume fraction by 28.6% (P =.008). Changes in the control group within the same period were small (all, P>.10). By day 8, the exercise group had a significantly better ejected venous volume (P<.001) and ejection fraction (P<.001) than the control group. The venous filling index and the venous volume did not change (P>.50) in either study group. Calf muscular endurance in the exercise group increased 135%, from a median 153 plantar flexions at baseline to 360 on day 7 (P<.001).

Conclusions: By increasing the muscular endurance, efficacy, and power of the calf muscle, isotonic exercise improves its ejecting ability and the global hemodynamic status in limbs with venous ulceration. Prospective evaluations of the clinical effects of calf muscle pump strengthening for the treatment of venous leg ulceration are indicated by the results of this study.