A101: Effects of Combining Electrical Muscle Stimulation with StrengthTraining on Lower Limb Mechanics With PFPS

<bold>Background:</bold> Patellofemoral pain syndrome (PFPS) is a common causative factor of knee pain. Exercise and electrical muscle stimulation (EMS) have been shown to improve knee function and relieve pain in patients with PFPS. However, the effect of exercise and EMS training on lower limb mechanics is unclear. The purpose of this study was to investigate the lower limb mechanics during single-leg squats following 6-week training interventions of exercise and EMS. <bold>Methods:</bold> 46 participants were recruited and randomly assigned into the muscle strength training (MST) group (21.5±3.8 yr, 174.7±8.4 cm, 69.5±11.7 kg) and combining EMS with strength training (EMS) group (22.2±4.3 yr, 173.8±7.4 cm, 72.4±13.2 kg) from the local university. Lower limb mechanics during single-leg squats were collected at the baseline and following the 6-week intervention for each group by using infrared motion capture systems and force platform. Two-way (group by time) analysis of covariance tests with repeated measures were applied to analyze the data. <bold>Results:</bold> ANCOVA with repeated measures indicated that during single-leg squat, both groups showed significant decreases in peak patellofemoral joint stress (<italic>F</italic>=30.384, <italic>P</italic> &lt; 0.001, <italic>η</italic> ²=0.459), peak patellofemoral joint stress force (<italic>F</italic>=25.063, <italic>P</italic> &lt; 0.001, <italic>η</italic> ²=0.379), knee extension moment (<italic>F</italic>=13.603, <italic>P</italic>=0.001, <italic>η</italic> ²=0.264), knee abduction moment (<italic>F</italic>=5.086, <italic>P</italic>=0.030, <italic>η</italic> ²=0.113) and knee external rotation moment (<italic>F</italic>=4.277, <italic>P</italic>=0.045, <italic>η</italic> ²=0.099) over time, but the EMS group had a larger change in peak patellofemoral joint stress (<italic>F</italic>=5.910, <italic>P</italic>=0.020, <italic>η</italic> ²=0.138) over time compared to the MST group. <bold>Conclusions:</bold> EMS training is beneficial for altering lower limb movement patterns and joint loading during single-leg squats in patients with PFPS compared to MST.