EMG Biofeedback and NMES of Deltoid in Patients With rTSA

NMES: Two electrode pads were placed on the anterior, middle, and posterior deltoid boundary lines and at a distance of 1cm distal to the lateral margin of the acromion. The operator palpated the deltoid muscle contraction and asked the subjects to perform arm elevation task with NMES. (frequency of 35 Hz and a duration of 250 microseconds.) A verbal cue was given during both th A verbal cue was given during both the sEMG biofeedback and NMES interventions: "Lengthen your arm as if you want to touch the ground, the scapula keeps in the neutral position, and then elevate your arm." Each intervention consisted of 3 sets of 10 repetitions per set, with a 1-minute rest between sets.

sEMG biofeedback: Subjects were instructed to monitor the sEMG signals of the D/UT balances ratio on the screen and maintain the D/UT balances ratio above the threshold during arm elevation and lowering. The threshold was set at 1 standard deviation of the ratio average at baseline (before intervention).