Efeitos da suplementação com Whey Protein associada à estimulação elétrica neuromuscular do quadríceps femoral após reconstrução do ligamento cruzado anterior

Abstract

After anterior cruciate ligament (ACL) reconstruction it is common to happen a dysfunction and muscular atrophy of the quadríceps femoris. The neuromuscular electrical stimulation (NMES) associated with Whey Protein may present positive results to help attenuate the loss of strength and trophism in periods of disuse, since these interventions are able to stimulate the muscle proteins synthesis. Thus, the aim of this study was to investigate the effects of Whey Protein supplementation associated with NMES in the quadriceps femoris in people submitted to ACL reconstruction. The sample consisted of 20 volunteers, who were randomized into 3 groups: 1) Basal Control (BC, n= 7), composed of volunteers who performed only the evaluations, 2) Whey Protein associated with NMES group (WE, n= 7), composed of volunteers submitted to NMES in the quadriceps femoris and Whey Protein supplementation, with a dose of 20g, three times a week for two consecutive weeks, 3) NMESgroup (EE, n= 6), composed of volunteers submitted only to NMES in the quadríceps femoris. All groups were evaluated in two moments: preoperative and postoperative. The following evaluation methods were used: evaluation form, estimated thigh measurement and surface electromyography (EMGs) in maximal voluntary isometric contraction (MVIC) of the femoral rectus (FR), vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST), femoral biceps (FB), gluteus maximus (GMAX), gluteus medius (GMED) and gastrocnemius medial head (G) muscles. After, it was performed simultaneously, the kinematic, baropodometric and EMG evaluations of the muscles mentioned above during the bipodal mini squat, with eyes open and subsequently closed. The results showed that only the WE group presented no decrease in the GMED muscle EMG activity in the MVIC of the operated limb. During the postoperative evaluation there was a decrease in the EMG activity of VM muscle in the operated limb during the mini squat with open eyes (p: 0.007) and closed eyes (p: 0.008) of the BC group. No difference was observed in the estimated thigh measurement at the postoperative moment in all study groups. It can be concluded that in the studied sample, whey protein associated with NMES was effective to maintain GMED muscle EMG activity during the MVIC. The NMES isolated or associated with whey protein was effective to maintain VM muscle EMG activity and prevented asymmetries in the body mass distribution during the mini squat movement in the studied sample. The interventions used in this study did not prevent asymmetry and kinematic alterations; however, there were some differences in the compensatory strategies between the groups. The estimated thigh volume measure did not change significantly after fifteen days of ACL reconstruction.