Effect of neuromuscular electrical stimulation on foot/ankle volume during standing.

Abstract

The purpose of this study was to assess whether the increase in foot and ankle volume after 30 min of motionless standing in healthy subjects could be minimized by neuromuscular electrical stimulation (NMES). A crossover, counterbalanced design was used where foot and ankle volume in 20 healthy subjects was measured using water volumetry before and after 30 min of motionless standing and standing with NMES applied to the lower leg muscles. The NMES produced repeated tetanic contractions of the gastrocnemius and tibialis anterior muscles causing slight ankle dorsi- and plantar-flexion. Posttest foot and ankle volume was significantly greater than pretest volume after 30 min of motionless standing (t = -7.093, P < 0.001), but no significant differences were found after 30 min of standing with NMES (t = -1.374, P = 0.185). The mean volume changes from pretest to posttest in the conditions without NMES and with NMES were significantly different (51 +/- 32 mL and 12 +/- 39 mL, respectively; t = 3.905, P = 0.001). This study demonstrates the potential uses of NMES as a means to reduce swelling in the lower limbs for individuals who do not fully activate the musculo-venous pump. The activation of the musculo-venous pump by NMES-induced muscle contraction may have minimized the increase in foot and ankle volume by increasing venous return, reducing venous stasis, increasing lymph flow, and increasing interstitial hydrostatic pressure, which would reduce capillary filtration and assist fluid reabsorption.