They consist of the subscapularis (anteriorly), the supraspinatus (superiorly), and the infraspinatus and teres minor (posteriorly). Injuries of the rotator cuff are common and may be chronic conditions or the result of the trauma. Traumatic injuries are more common in the older population and are often related to a fall with an indirect force on an abducted arm. Tendinitis of the rotator cuff is very common and can be a result of respective overhead activities or incorrect body mechanics during weight training. Activities such as tennis, swimming, and throwing can eccentrically overload the rotator cuff and cause tendinitis.
Carrying and lifting heavy bags in daily life is another common mechanism of injury. In addition, excessive shoulder laxity or instability can predispose a person to this pathology by making the rotator cuff work much harder.
A common diagnosis of the rotator cuff is referred to as impingement syndrome. This refers to the impingement of the soft tissues between the humeral head and the archway that is formed by the acromion and the coracoacromial ligament. Conditions that narrow this archway, such as soft-tissue swelling, bone spurs or arthritic changes, can predispose an individual to impingement. For some individuals, the acromion is congenitally hooked or curved in shape- as opposed to flat- which may predispose the client to an impingement syndrome as the acromion rubs on the rotator cuff.
The most common structures affected are the supraspinatus, the infraspinatus, the long head of the biceps, and the subacromial bursa. A bursa is a sac of fluid that is present in areas of the body that are potential sites of friction. With overuse, a bursa can become swollen and inflamed, resulting in bursitis. As the tendons become inflamed, they may rub on the bone and become frayed and eventually lead to chronic rotator cuff tears, which can vary greatly in terms of size, thickness and location. These tears may continue to get larger until surgical intervention may be required. Surgical intervention id determined by several factors such as pain, loss of function, activity level, and the amount of repairable tissue available.
Rotator cuff injuries will vary greatly depending on the location and severity of the injury. The duration of the injury is also often a factor. A person with a torn or inflamed rotator cuff may present with pain or weakness with resistive external rotation. Supraspinatus pathology is often considered with pain and/or weakness with resistive flexion with internal rotation in the plane of the scapula (the ‘empty can’ position) (Jobe & Jobe 1983).
In addition, passive full forward flexion (Neer test) and passive forward flexion and internal rotation (Hawkins & Kennedy 1980) may elicit pain. Weakness is sometimes a function of the severity of the injury, but there is a great deal of variability. Individuals with massive tears of the rotator cuff may have difficulty initiating elevation of the arm or maintaining it in an abducted position, but this is not always the case. These clients may not be appropriate for training and need to be referred back to their therapist or physician. Finally, individuals with rotator cuff pathology may describe ‘a painful arc’ of range motion. As they approached 90 degrees of elevation of the shoulder, they reach the impingement zone and complain of pain that then resolves as they move beyond that zone. The initial stages of training individuals with rotator cuff injuries focus on reducing inflammation and promoting healing. This is a stage of ‘active rest’ in which exacerbating activities are eliminated or modified. Common causes of injury are overhead sports, military press, incline bench press, and lateral raises in the front plane. Restoring flexibility is also an important goal of this phase. Individuals with rotator cuff pathology often lose flexibility of the posterior structures of the shoulder. Loss of horizontal adduction is often an indication of a contracture of the posterior rotator cuff. Both of these situations can contribute to an increased chance or rotator cuff impingement. Flexibility exercises are initiated to restore range of motion. As always avoid ranges that are painful.
As in the case of shoulder instability, strengthening should be initiated with the scapula, especially in the case of a significantly inflamed rotator cuff. Any deviation in scapular function can have a negative effect on the shoulder. For example, if the scapula is elevated too high, the mechanical advantage of the rotator cuff is altered. By restoring the normal scapula function, the proper length-tension relationship of the rotator cuff is restored. In addition, many of the scapula strengthening exercises (rowing, shrugs, serratus punches, push-ups with a plus) indirectly strengthen the rotator cuff (Hintermeister 1998).
As inflammation decreases, internal and external rotation exercises may be cautiously introduced. It should be noted that not everyone can tolerate these exercises. Strengthening can be introduced as submaximal isometrics. Clients can then progress to using elastic resistance. When performing external rotation exercises, the client can position a towel roll at his or her side, which places the shoulder in a slightly abducted position. This will improve the blood supply to the shoulder and enhance the mechanical advantage of the external rotators.
For those who want to continue deltoid strengthening, scapular plane elevation is preferred to performing lateral raises in the frontal plane. The exercise in the scapular plane affords the least amount of stress on the shoulder. It is also a more functional plane in which to work. Finally, this exercise also recruits much of the scapula musculature and to some extent the supraspinatus. (Moseley, Jobe, Pink 1994.) The ‘empty can’ position described by Jobe & Jobe (1983) for strengthening the supraspinatus is not advised, as the internally rotated position significantly increases the chance of shoulder impingement and is a common source of shoulder pain.
When designing a strength-training programme, one should consider that many athletic or functional demands require a significant amount of eccentric muscle activity. Therefore, the eccentric or negative phase of each exercise should also be emphasized). Many clients with rotary cuff injuries will want to return to overhead activities such as tennis, swimming, or throwing. In such cases, multijoint activities such as proprioceptive neuromuscular facilitation (PNF) patterns are useful to reproduce these demands. In particular, the D2 flexion pattern, which consists of shoulder flexion, abduction and external rotation, reproduces the neuromuscular demands of many overhead activities.
When a client is returning to performing a bench press, a narrower hand spacing should be utilized to minimize the peak shoulder torque in the pressing motion and reduce the rotator cuff and bicep tendon requirements for stabilization of the humeral head (Fees 1998).
Richard Geres is an ACE-certified
Personal Trainer
www.richardgeres.com