Comparisons of Shoulder Muscle Activity and Muscle Activity Ratio during Serratus Anterior Exercise between CrossFit Practitioners with/without Shoulder Impingement Syndrome

Purpose@#Due to the high incidence of shoulder injuries, including shoulder impingement syndrome (SIS), among CrossFit practitioners due to frequent overhead movements, serratus anterior exercises are considered crucial for scapular stabilization in both intervention and prevention. @*Objective@#The objective of this study is to compare the muscle activity and ratios of scapular stabilizing and shoulder girdle muscles between individuals with and without SIS during serratus punch and wall slide exercises, both targeting the serratus anterior muscle, in CrossFit training practitioners. @*Methods@#Surface electromyography was used to compare the muscle activity and activity ratio of scapular stabilizing muscles and shoulder muscles during serratus punch and wall slide exercises in two groups of 20 CrossFit practitioners: ten with SIS and ten without symptoms. @*Results@#The group with SIS showed higher activation of the pectoralis major, upper trapezius, and a higher pectoralis major/serratus anterior and upper trapezius/serratus anterior muscle activation ratio during the serratus punch exercise compared to the group without SIS. Similarly, during the wall slide exercise, the group with SIS exhibited higher activation of the upper trapezius and a higher upper trapezius/serratus anterior muscle activation ratio compared to the group without SIS. However, no significant difference in serratus anterior muscle activation was observed between the two groups. @*Conclusions@#This study highlights the higher activation of the pectoralis major and upper trapezius muscles in CrossFit practitioners with SIS during the serratus anterior exercise, suggesting the importance of minimizing the overactivation of these muscles to prevent impingement syndrome in this population.

Effects of Trunk Control Rehabilitation Robot Training on Dynamic Balance, Lower Extremity Strength, Gait Ability and Pain in Bipolar Hemiarthroplasty

PURPOSE: This study examined the effects of trunk control rehabilitation robot training (TCRRT) on the dynamic balance, lower extremity strength, gait ability and pain for bipolar hemiarthroplasty. METHODS: Hemiarthroplasty (n=28) patients participated in this study. The subjects were randomized into two groups: trunk control rehabilitation robot training group and control group. RESULTS: The TCRRT group showed significantly more improvement in the MFRT, MMT, 10MWT, TUG, and VAS compared to that before intervention (p<0.05). In addition, all tests were significantly greater in the experimental group than in the control group. CONCLUSION: These results suggest that TCRRT is feasible and effective for improving the dynamic balance, lower extremity strength, gait ability, and pain efficacy after bipolar hemiarthroplasty.