Electromyography analysis of rotator cuff activation while driving

Background A common concern of patients after rotator cuff repair (RCR) is when they can drive. The purpose of this study is to evaluate the activation of the rotator cuff while driving to help guide surgeon recommendations. Methods A computerized driving simulator was used by 16 volunteers who performed a series of turns with their hands in different positions on the steering wheel. Muscle activity of the supraspinatus, infraspinatus, and biceps was recorded using electromyography (EMG). Muscle activity was also recorded while closing the door, fastening the seat belt, and turning a key in the ignition and quantified by a board-certified electromyographer. Results For the right supraspinatus, infraspinatus, and biceps muscles, there was statistically significant higher level of activation when the right hand was in the 12 o'clock position and the 3 o'clock position as compared with the 6 o'clock positions. This was the same for the left side with the left hand in the 12 o'clock and 9 o'clock positions compared to the 6 o'clock positions (p<0.003). Activity of all muscles was minimal when the car door was closed with the opposite hand. Fastening the seat belt and turning the key in the ignition also demonstrated rotator cuff activation. Conclusion Rotator cuff activity during driving can be minimized by closing the door using the non-operative arm and driving with the non-operative arm in the 12 o'clock position with the operative arm at the side and holding the wheel at the 6 o'clock position.