Electrical stimulation during gait promotes increase of muscle cross-sectional area in quadriplegics: a preliminary study.

Increases in muscular cross-sectional area (CSA) occur in quadriplegics after training, but the effects of neuromuscular electrical stimulation (NMES) along with training are unknown. Thus, we addressed two questions: (1) Does NMES during treadmill gait training increase the quadriceps CSA in complete quadriplegics?; and (2) Is treadmill gait training alone enough to observe an increase in CSA? Fifteen quadriplegics were divided into gait (n = 8) and control (n = 7) groups. The gait group performed training with NMES for 6 months twice a week for 20 minutes each time. After 6 months of traditional therapy, the control group received the same gait training protocol but without NMES for an additional 6 months. Axial images of the thigh were acquired at the beginning of the study, at 6 months (for both groups), and at 12 months for the control group to determine the average quadriceps CSA. After 6 months, there was an increase of CSA in the gait group (from 49.8 +/- 9.4 cm(2) to 57.3 +/- 10.3 cm(2)), but not in the control group (from 43.6 +/- 7.6 cm(2) to 41.8 +/- 8.4 cm(2)). After another 6 months of gait without NMES in the control group, the CSA did not change (from 41.8 +/- 8.4 cm(2) to 41.7 +/- 7.9 cm(2)). The increase in quadriceps CSA after gait training in patients with chronic complete quadriplegia appears associated with NMES.

Muscle hypertrophy in quadriplegics with combined electrical stimulation and body weight support training.

We describe the analysis of muscle hypertrophy in complete quadriplegics after 6 months of treadmill gait training with neuromuscular electrical stimulation (NMES). We aim to evaluate the effect of treadmill gait training using NMES, with 30-50% body weight relief, on muscle mass. Fifteen quadriplegics were divided into gait (n=8) and control (n=7) groups. The gait group (GG) performed training, associated to partial body weight support, for 6 months, twice a week, for 20 min. Control group (CG) individuals performed only conventional physiotherapy, but did not perform gait training using NMES. Magnetic resonance imaging (MRI) was performed over quadriceps, at the beginning and after 6 months. The MRI was done to determine the average of cross-sectional area of the quadriceps. Moreover, a gray scale was used to separate the muscle from the conjunctive tissue (when the value is closer to 225, there is a higher amount of muscle tissue). After 6 months there was an increase of cross-sectional area in the gait group (from 49.81+/-9.36 to 57.33+/-10.32 cm2; P=0.01), but not in the control group (from 43.60+/-7.56 to 41.65 +/- 9.44 cm2; P=0.17). The gray scale did not show significant differences after 6 months; however, the mean value of the gray scale inside the quadriceps in the gait group increased by 7.7% and in the control group decreased by 11.4%. Treadmill gait associated with NMES was efficient to promove quadriceps muscle hypertrophy in quadriplegics with chronic lesions even when a partial body weight support was provided.