Ingber, R. S. (2000). Shoulder impingement in tennis/racquetball players treated with subscapularis myofascial treatments. Arch Phys Med Rehabil, 81(5), 679-682.

BACKGROUND

Shoulder impingement syndrome is a problem for many individuals involved in vigorous overhead shoulder motions such as racquet sports. Impingement syndrome is primarily caused by compression of the sub-acromial soft tissues underneath the acromion process of the scapula or the coracoacromial ligament of the shoulder. Impingement is generally treated conservatively, but surgical intervention may be used if conservative treatment is not successful.

Surgical treatment usually consists of subacromial decompression and acromioplasty. These are procedures that are designed to reduce compression on the soft tissues in this region by increasing the space between the acromion process and the soft tissues underneath it (see Figure 7). The underside of the acromion process will be shaved somewhat in order to create a smooth contact surface and reduce the likelihood of irritating compression of the soft tissues.

Surgical treatment for shoulder impingement is usually effective in relieving symptoms. However, many people would prefer not to have surgery. In addition the authors of this study state that many of the surgical procedures for shoulder impingement achieved good results in pain relief, but were not as successful regarding return to function. For this reason, they were investigating whether or not restoring proper biomechanics to the soft tissues underneath the acromion process may be an effective way to treat this problem.

One of the factors investigated in this study is the role of the subscapularis muscle in shoulder impingement problems. The proper function of the subscapularis muscle is generally not considered as strongly when investigating shoulder impingement because it doesn't travel underneath the acromion process. However, these authors found that biomechanical dysfunction involving the subscapularis played an important role with a number of their patients.

The subscapularis muscle has a crucial function in racquet sports just before the rapid acceleration that is involved in overhead motions like the tennis serve. The shoulder goes back in a motion of external rotation and extension during the cocking phase and then immediately is accelerated into internal rotation to generate force of the forward swing of the racquet. This stretching of the subscapularis in external rotation that is immediately followed by a contraction (producing rapid internal rotation) is referred to as the stretch-shorten cycle. The large tensile forces produced on the muscle while it is in an elongated position in this action produce significant eccentric muscle injury and dysfunction that often lead to common myofascial trigger points.

This study describes three separate cases with racquet sports players where there was evidence of shoulder impingement syndrome and dysfunction of the subscapularis muscle. They were each treated with a dry needling technique as well as soft tissue massage. Dry needling technique is a method of probing and contacting myofascial trigger points with a needle, but not injecting any substance into them. In this study the authors used acupuncture needles for the dry needling technique. The massage methods consisted of direct compression techniques to the active trigger points in the subscapularis muscle. Each patient was also instructed in proper stretching methods as well.

DISCUSSION

Each of the three patients in this study had beneficial outcomes in both pain reduction and return to optimal function. Follow up was done by telephone interview and at one year post treatment they were all pain free and back to their original level of activity.

The subscapularis muscle has been shown to have a significant role in the late cocking phase of throwing motions. There is a good indication that biomechanical disturbances to the subscapularis, such as myofascial trigger point activity may impede proper shoulder mechanics and therefore be a part of creating shoulder impingement. Based on the clinical approach taken in these cases there is an indication that myofascial treatment of the subscapularis muscle may be a crucial part of shoulder impingement treatment for racquet sports players. The authors of this article state that six to eight treatments may be required over a 2 to 3 month period. However, the individual should be able to see some measurable results within the first 2 to 3 treatments.

The information presented in this article is a valuable acknowledgement of the beneficial effects of myofascial treatments for soft tissue disorders such as shoulder impingement syndrome. Yet this certainly opens up further questions for study as well. Is it possible that the same results could be achieved with soft tissue manipulation alone instead of using dry needling? This would be an advantage for those who may have an aversion to needle therapy or for those practitioners like massage therapists who may not perform invasive procedures because it is outside their scope of practice.

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