Serratus anterior muscle activity during selected rehabilitation exercises

The purpose of this study was to document the electromyographic activity an d applied resistance associated with eight scapulohumeral exercises perform ed below shoulder height. We used this information to design a continuum of serratus anterior muscle exercises for progressive rehabilitation or train ing. Five muscles in 20 healthy subjects were studied with surface electrod es for the following exercises: shoulder extension, forward punch, serratus anterior punch, dynamic hug, scaption (with external rotation), press-up, push-up plus, and knee push-up plus. Electromyographic data were collected from the middle serratus anterior, upper and middle trapezius, and anterior and posterior deltoid muscles. Each exercise was partitioned into phases o f increasing and decreasing force and analyzed for average and peak electro myographic amplitude. Resistance was provided by body weight, an elastic co rd, or dumbbells. The serratus anterior punch, scaption, dynamic hug, knee push-up plus, and push-up plus exercises consistently elicited serratus ant erior muscle activity greater than 20% maximal voluntary contraction. The e xercises that maintained an upwardly rotated scapula while accentuating sca pular protraction, such as the push-up plus and the newly designed dynamic hug, elicited the greatest electromyographic activity from the serratus ant erior muscle.