ACC Sports Sciences Main Page
Stephen Wiley, ATC-L, PT
Wake Forest University Sports Medicine
As the tennis season progresses, even the well-conditioned collegiate athlete can feel the effects of the many serves, forehands, backhands, volleys, and overheads required in a collegiate tennis season. In tennis, the incidence of traumatic type injuries is relatively low. The typical mechanism of injury for the tennis participant is overuse, which results in a mechanical breakdown. Not surprisingly, the joint most often affected is the shoulder complex. The demands that each stroke in tennis place on the shoulder are tremendous, and the additive effect over the course of the season can be staggering.
The injury that can derail the season of a tennis athlete or any athlete whose sport demands repetitive overhead activity is rotator cuff tendonitis.
What is the rotator cuff? What is its function?
The rotator cuff is a group of muscles that surrounds the head of the humerus (upper arm) and provides dynamic stability of the shoulder joint as the shoulder moves through its range of motion (ROM). The humerus articulates with the glenoid fossa on the scapula to form the gleno-humeral (shoulder) joint. Think of it as a ball and saucer joint. The joint is surrounded by a fibrous capsule and ligaments but the rotator cuff is the prime stabilizing force for athletic activity. There are four muscles that compose the rotator cuff: supraspinatus, infraspinatus, subscapularis, and teres minor. These muscles work together to form force couples (groups of muscles working in unison) to limit the amount of upward sliding of the humeral head in the glenoid. This combined work by these four muscles maintains the appropriate mechanics to allow the shoulder to achieve full ROM overhead without mechanical breakdown.
What is rotator cuff tendonitis?
Rotator cuff tendonitis is an inflammation of the tendons that compose the rotator cuff which typically results in pain and swelling in these tissues.
What causes rotator cuff tendonitis?
Rotator cuff tendonitis can have a variety of causes. One of the most common causes is weakness in the rotator cuff that allows excessive motion of the humeral head in the glenoid, thus overstressing the rotator cuff as it tries to decelerate or check excessive motion of the humeral head. Another possible cause is impingement of the rotator cuff. Rotator cuff impingement can occur because of postural issues, structural issues, mechanical issues, or trauma. Repetitive impingement sets up the irritation or micro-trauma to the rotator cuff that can cause and exacerbate rotator cuff tendonitis.
Postural problems can develop from a head forward and rounded shoulder posture which is very typical in today's society. This creates a narrower anterior sub-acromial space. The sub-acromial space is the small area between the rotator cuff and the acromion wing on the scapula. If this area is narrowed, if will predispose the tennis player to impinge the anterior rotator cuff with serves, overheads, and on the forehand follow-through.
Structural issues that can contribute to shoulder impingement include tightness in the posterior ligamentous/capsular components of the gleno-humeral joint. Another possible contributing factor is the shape of the acromion. A hooked or curved acromion can narrow the sub-acromial space and contribute to impingement with overhead activity. The worst possible combination of structural deviations is the hooked acromion with a bone-spur formation on the acromion. This maximizes the narrowing in the sub-acromial space and almost always causes damage to the rotator cuff over time.
Mechanical issues can also cause rotator cuff impingement. Appropriate shoulder mechanics require a 2:1 ratio of arm motion to scapular upward rotation. If this scapula-humeral rhythm is disrupted, excessive gleno-humeral motion accompanied by insufficient scapular upward rotation may contribute to impingement. Another possible mechanical deviation is a breakdown in rotator cuff function as a result of weakness. If the weakness is so great that it allows the humeral head to slide superiorly and pinch on the underside of the acromion, this repetitive micro-trauma can cause impingement.
A final possible cause of rotator cuff impingement is direct trauma. A fall directly onto the shoulder is unlikely in tennis. More likely is a slip and fall onto an outstretched arm which can cause the humerus to jam into the acromion and result in a traumatic shoulder impingement syndrome.
How to recognize rotator cuff tendonitis
Rotator cuff tendonitis can present with a variety of signs and symptoms. The athlete will typically complain of shoulder pain that is located primarily in the anterior or lateral shoulder. They may also report pain/spasm in the upper trapezius muscle (lateral neck). Typically, pain will accompany their specific activities, particularly forceful motions and shoulder motions to the front and side. The athlete might complain of difficulty sleeping on the involved shoulder because of pain. The athlete may also demonstrate decreased strength, particularly as the arm is elevated or specifically in the rotator cuff tendons.
If impingement is a contributing factor, the athlete may complain of a painful arc with shoulder abduction (motion lifting to the side). They may also complain of pain with impingement positioning-reaching overhead for serve or with follow-through on the forehand stroke.
Diagnosis and Initial Treatment
Rotator cuff tendonitis is difficult to self-diagnose and typically will require more that just the typical conservative management techniques of R.I.C.E. (Rest, Ice, Compression, Elevation). A sports medicine physician will likely need x-rays to rule out other diagnoses and check to see that there are no structural factors contributing to the rotator cuff tendonitis. The physician may also recommend a non-steroidal anti-inflammatory (NSAID) or an injection of cortico-steroid to help alleviate the pain and inflammation. Physical therapy may also be prescribed to assist with resolving the problem through rehabilitation and to rectify the causative factors that led up to the injury.
Rehabilitation will likely include activity modification to limit further irritating factors. It will also focus on the improving the mechanics of motion through flexibility, stretching, and strengthening techniques. The strengthening exercises will address weaknesses found in the rotator cuff itself, muscles that affect scapular mechanics and motion, and the core (trunk). Modalities may also be incorporated to assist with the healing process and pain control. These may include superficial moist heat, ultrasound, electrical stimulation, and ice. Return to full activity without limitation should be guided as the strength, ROM, and functional status improve and the athlete is able to progress though limited practices without re-exacerbation of pain or other symptoms.
If symptoms persist, referral back to the physician should occur. At this point, the physician may request a MRI or arthrogram to rule out rotator cuff tear or other structural damage.
Prevention of rotator cuff tendonitis
Prevention is the best way to avoid rotator cuff injury. To accomplish this, the athlete must diligently work to improve and maintain good resting posture; improve the strength of the rotator cuff and supporting parascapular musculature, and work to improve core strength.
A good rotator cuff prevention program would incorporate the following components:
1) External rotator strengthening
2) Internal rotator strengthening
3) Good pectoral muscle flexibility
4) Good rhomboid, lower trapezius, serratus anterior, upper trapezius strength
5) Co-contraction activities and closed chain activities (Closed chain activities are those where the hand is fixed and the body moves over this fixed point.)
6) Deltoid strengthening
7) Bicep and tricep strengthening
8) Core strengthening program
Unmanaged rotator cuff tendonitis
Rotator cuff tendonitis that becomes chronic can cause serious damage to the rotator cuff. A rotator cuff tear is a much more serious issue that typically requires surgical intervention. Even if a rotator cuff tear does not develop, the athlete is likely to develop compensations or adaptations altering the technique/form which made him/her so successful.
The complex balance of strength, stability, and mobility in the shoulder often are upset by the demands placed on it by competitive athletes. It is important to pay attention to shoulder signs and symptoms because rotator cuff tendonitis can be prevented with a comprehensive shoulder program. If tendonitis does develop, it can be managed with rehabilitation to prevent extended time lost from sports activity.