In an experimental study we investigated the EMG response in 10 patients after intraarticular stimulation of the joint capsule. Intraoperative stimulation was achieved by arthroscopic placement of the stimulation catheter at the anterior joint capsule. The muscle response was documented by mono- or bipolar electrodes. We found reproducible EMG muscle responses in both superficial and deep muscle layers. The response time was between 100 and 516 ms. The shortest muscle response was found at the anterior part of the deltoid muscle and the longest at the supraspinatus muscle and the lateral part of the deltoid muscle.