Comparison of Muscle Electromyography Changes During Walking in Athletes With Anterior Cruciate Ligament Reconstruction and Healthy Peers

Background and Aims This study aims to compare the muscle electromyography changes during walking in athletes with anterior cruciate ligament reconstruction (ACLR) and healthy peers. Methods This is a causal/comparative study. The participants were 46 football and volleyball players (with at least 3 years of experience in sports activities) in two groups of individuals with ACLR who had reconstruction at least six months ago (n=23, mean age: 24.39±7.17 years) and healthy peers (n=23, mean age: 25.09±7.28 years. Electrical activity of eight muscles (tibialis anterior, medial gastrocnemius, vastus medialis, rectus femoris, biceps femoris, gluteus medius, erector spinae, and rectus abdominis) was measured by an 8-channel electromyography device in two phases; 100 ms before heel strike (swing phase) and 200 ms after heel strike (stance phase) during walking. For data analysis, the Shapiro-Wilk test was used to check the normality and Levene’s test to check the homogeneity of the data. Independent T-test was used to compare the two groups. Results The intensity of activity significantly decreased in the ACLR group during the swing and stance phases only in the vastus medialis muscle, compared to the healthy group (P=0.03). The start time of the peak muscle activity during walking (swing phase) for in the ACLR group was significant delayed only in the vastus medialis (P=0.01), erector spinae (P=0.006) and rectus abdominis (P=0.03) muscles compared to the healthy group. The length of time to reach the peak activity in 200 ms after heel strike (stance phase) in the ACLR group was statistically shorter only in the vastus medialis (P=0.001), erector spinae (P=0.04) and rectus abdominis (P=0.01) muscles, compared to the healthy group. Conclusion The intensity and duration of firing in vastus medialis muscle are significantly reduced in athletes with ACLR compared to healthy peers. In the erector spinae and rectus abdominis muscles, only the duration of firing rate is significantly reduced in these people. In developing rehabilitation programs, it is better to pay special attention to improving the contraction intensity and timing of the lower limb muscles, especially the vastus medialis muscle, as well as to the core muscles, including rectus abdominis and erector spinae.