Neuromuscular electrical stimulation after anterior cruciate ligament reconstruction surgery : Effects on rate of torque development and electromechanical delay

Abstract: Abstract Aim: The main objective of this study was to compare electro mechanical delay (EMD) and rate of torque development (RTD) of the knee extensors 6 weeks after rehabilitation of anterior cruciate ligament reconstruction (ACLR) with or without neuromuscular electrical stimulation (NMES). Further the feasibility of the study was examined. Method: 10 participants were randomized into two groups, one neuromuscular electrical stimulation group (NMESG) and one training group (TG). The NMESG used a NMES-device as a complement to the ordinary rehabilitation protocol. Regular meetings with a physiotherapist were scheduled during the rehabilitation. Measurements of RTD and EMD during knee extension were made in an isokinetic dynamometer with electromyography recordings (EMG) from the knee extensors 6 weeks after surgery. Results: All participants completed the study. The NMESG went to see the physiotherapist 6.7 ± 2.5 times and the TG 6.8 ± 1.8 times. The participants in the NMESG used the NMES-apparatus 28 ± 1.7 times. Total number of training days for the NMESG was 25 ± 4 and for the TG 35 ± 1. RTD did not significantly differ between the groups. For the TG, RDT was 901.1, 941.2 and 531.0 Nm/s, over the first 50, 100 and 200 ms, respectively. For NMESG: RTD was 824.3, 966.2 and 529.0 Nm/s, over the first 50, 100 and 200 ms, respectively. No significant difference between the groups or interaction between group and muscle was found in EMD. For both groups EMD was significantly larger for vastus medialis as compared to the vastus lateralis and rectus femoris. Conclusions: The study was feasible to perform, and despite fewer training days for the NMESG, no significant group differences were found in RTD or EMD. A larger study population is needed to evaluate the efficacy of the intervention.