Shoulder Injury Prevention

... in Athletes and Others

The shoulder is one of the most amazing joints in the body. In fact it is not a 'joint', but rather a 'complex' of 5 joints, over 30 muscles and 6 major ligaments. The shoulder can assume no less than 1,600 different positions! There is more movement at the shoulder joint than at any other joint in the body. As such, it is easily prone to overuse and injury.
Athletes, such as swimmers, tennis players, golfers, baseball pitchers, javelin throwers, cricketers, rugby players and martial artists use their shoulders a huge amount and often take it for granted.

Shoulder Pain

Chronic shoulder injury is a common problem, and not just for athletes. Among the population at large, day-to-day activities such as DIY or gardening can produce chronic pain, as can resistance work in the gym, when enthusiasts pile on the weight without paying heed to the need for balanced strengthening.
Any overhead activity that involves the arm being taken often enough from below the shoulder level to above shoulder level has the capacity to damage the rotator cuff. With repeated impingement, a poorly conditioned cuff can become damaged, and a cycle of cuff damage, impaired function, further impingement and worsening cuff damage is initiated.

Injury prevention

Shoulder injuries can often be prevented, by following simple guidelines. Pre-season screening of athletes by an experienced physiotherapist can help prevent common sports injuries. This should include assessment and management of the following key areas:

1. Sports-specific technique
2. Flexibility
3. Core stability
4. Rotator-cuff control
5. General strength

Sports-specific technique: poor performance and shoulder pain commonly originate in bad habits of technique. Often they are only clearly seen when muscle fatigue sets in. The variety of overhead movements required for each sport gives rise to very subtle and unique technique faults. These will depend on the type of sport and shoulder dominance.

Flexibility: flexibility varies for the different muscles around the shoulder. For the major power muscles, it is important that flexibility allows freedom of movement for the pelvis, trunk, scapula, and humerus. For the rotator cuff, the critical issue is the balance of forces centering the head of the humerus, and to a lesser degree, freedom of movement. It is more critical that the internal and external rotators are equally flexible, rather than how flexible they are.

Core stability: core stability is critical it is for the inner core of the body and providing a stable strong support for the shoulder to work off. A good shoulder needs a good foundation. The core also provides the kinetic chain for overhead activities, allowing the trunk muscles to transfer energy and momentum to the shoulder for overhead sports. For the shoulder, the critical areas are the lumbar and cervical spine and the scapulothoracic joint. If these areas are not stable, significant extra loading and strain is passed on to the shoulder joint

Rotator-cuff strength and control: the rotator-cuff muscles are dependent on the good positioning of the scapula for effective control. If the scapula is angled too far forward or downward, for instance, while the tennis player reaches overhead to smash, the rotator-cuff muscles are biomechanically disadvantaged and may result in failure of the prime mover muscles to generate power. The rotator cuff should be balanced throughout the overhead movement, centering the humeral head on the glenoid. This requires equal strength and flexibility of the force couples of the rotator cuff.

General muscle strength: once the essential issues of technique, flexibility, core stability, and rotator-cuff control are being implemented, we then should also look at the 'outer core'. What is the rest of your body like - does it help or hinder the performance of the shoulder?

Athletes often overwork and build up their 'mirror muscles' at the front of the shoulder, such as pec major, front deltoids, trapezius and rectus abdominis ("six pack"). What is often critically overlooked, however, is the imbalance that can develop between the front of the shoulder and the back. In those athletes that are carrying an overuse injury in the shoulder, nine times out of ten they have overdeveloped pecs and lats relative to their lower trapezius, rhomboids, posterior deltoids, and posterior rotator cuff.

Prevention strategies

Balance upper-body workouts: a good way to avoid shoulder injuries is to make sure upper-body strength sessions are balanced. Redressing the imbalance caused by strong front muscles and weaker back muscles is important for the prevention and rehabilitation of shoulder impingement injuries.

Limit range of movement and take it easy: rehabilitation from a shoulder impingement injury should focus on rotator-cuff strengthening. It is important to remember that when it comes to re-introducing weight-training exercises, you must progress slowly.

It's also important to avoid certain ranges of motion where the shoulder joint sub-acromial space is compressed the most.
Correct scapula positioning when performing exercises: the correct position for the scapula (shoulder blade) is back and rotated down. Essentially, this means maintaining a good 'military posture', with shoulders back and chest out. A round shouldered or hunched posture is to be avoided at all times.

To achieve the correct position, you need to use rhomboids, mid and lower trapezius muscles to retract the shoulder and pull the scapula down.

Sports-specific exercises - plyometrics for the shoulder: just as rehabilitation training for leg injuries requires a functional progression from simply strength exercises to sports-specific exercises, so does rehab for the shoulder.
This means that for the athlete, eg a thrower or tennis player, conventional resistance exercises in the gym may not be enough to allow a full return to competition. Often what are needed to bridge the gap are plyometric exercises for the shoulder that mimic sports-specific movements.

Plyometrics for the shoulder usually involve medicine balls of various weights. Plyometric exercises have two advantages. First, they are performed fast, and second, they involve stretch-shortening cycle movement patterns.
This means they are much more sports-specific than conventional resistance exercises. In particular, plyometric exercises for the rear-shoulder and external rotator muscles are very useful because they provide eccentric training for these muscles. This improves their ability to control the shoulder during the powerful concentric actions of the pectorals and anterior deltoid involved in throwing or serving.