Electromyography analysis of shoulder joint muscles in standing with three ambulatory aids

Abstract

We investigated the muscle activity of the shoulder joint during single-leg standing three types of ambulatory aid, T-shaped cane (T-cane), Quadripod cane (Q-cane) and Lofstrand crutch (L-crutch) in which were used. The left leg of eight healthy volunteers was assumed to be an affected leg. All participants were asked to keep 20% of the weight-bearing load on the ambulatory aid and the electromyography (EMG) was recorded. Results of the analysis of variance followed by Fisher's PLSD post hoc test reveal that EMG values of the medial and posterior part of the deltoid muscle were significantly related to the three types of ambulatory aid, but the anterior part of the deltoid was not. EMG values of the biceps brachii, triceps brachii, and latissimus dorsi were significantly larger in T-cane and Q-cane users than in L-crutch users, and EMG of the pectoralis major was significantly larger in Q-cane users than in L-crutch users. These results permit us to select an appropriate ambulatory aid for patients.