Serratus anterior: What is the best exercise?

The serratus anterior muscle is an important upward rotator of the scapular. Often, however, it is a rather neglected muscle in shoulder rehabilitation programs, with many practitioners focusing on the other important scapular upward rotator being the trapezius, and specifically the lower trapezius.

While the trapezius is an important muscle, activity of the serratus anterior is significantly reduced relative to the trapezius in patients with shoulder impingement syndrome during all phases of elevation (Ludewig & Cook 2000). Whether this is the cause or the result of the impingement is unknown. Regardless, it points clearly to a need to address this weakness within an exercise rehabilitation programme.

The most common exercises prescribed by practitioners for strengthening the serratus anterior are those involving protraction. Many variations of the push-up plus have been studied and validated to activate the serratus anterior. Supine shoulder protractions, and more novel exercises such as the dynamic hug also have some evidence behind them.

However, from our literature research one of the most effective exercises for eliciting serratus anterior exercises is also one of the simplest. And as we are always seeking improved adherence from our patients then simple is definitely best.

The exercise is shoulder scaption above 120 degrees. Two studies have researched this exercise. Ekstrom et al (2003) showed that that it elicited a 96% MVIC of the serratus anterior. Hardwick et al (2006) also showed similar high activation. This compares with the dynamic hug exercise at 62% and a supine unilateral press exercise with full protraction at 53%.

This exercise has an advantage for those with impingement. As it is performed above 120 degrees it can avoid the painful arc and allow for strengthening to occur overhead. With the very high activation levels of serratus anterior, this could well be an exercise to really improve serratus anterior strength and optimise scapular function, while avoiding aggravation of the impingement syndrome.

Hardwick et al (2006) suggested the wall slide exercise might be a better overhead exercise to implement earlier in the rehabilitation process, while still activating serratus anterior to a high level. We agree this could well be the case, however some patients may find the wall slide more technically difficult. In the absence of pain, scaption above 120 degrees is probably still the best option in our opinion due to the simplicity of the exercise.

In those patients perceived to have excessive upper trapezius activity, the push-up plus variations may be more appropriate due to a favourable serratus anterior vs upper trapezius ratio (Ludewig et al 2004). However the view on excessive upper trapezius activity driving shoulder impingement pathologies remains a contentious issue.

In summary, shoulder scaption above 120 degrees is an effective exercise for eliciting high activity of the serratus anterior. It is worth putting this in your toolbox and for that reason we have recently included it in the TrackActive Pro database. As always, we must use our clinical judgment on whether the exercise is appropriate for our patients. This is the basis of evidence-based practice.

REFERENCES

Ekstrom, R. A., Donatelli, R. A., & Soderberg, G. L. (2003). Surface electromyographic analysis of exercises for the trapezius and serratus anterior muscles. Journal of Orthopaedic & Sports Physical Therapy, 33(5), 247-258.

Hardwick, D. H., Beebe, J. A., McDonnell, M. K., & Lang, C. E. (2006). A comparison of serratus anterior muscle activation during a wall slide exercise and other traditional exercises. Journal of Orthopaedic and Sports Physical Therapy, 36(12), 903.

Ludewig, P. M., & Cook, T. M. (2000). Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Physical therapy, 80(3), 276-291.

Ludewig, P. M., Hoff, M. S., Osowski, E. E., Meschke, S. A., & Rundquist, P. J. (2004). Relative balance of serratus anterior and upper trapezius muscle activity during push-up exercises. The American journal of sports medicine, 32(2), 484-493.