**17. Shoulder injuries**

The shoulder itself is made up of three bones, namely the humerus, the scapula and the clavicle. The rotator cuff is made up of four different muscles: the supraspinatus, infraspinatus, subscapularis and biceps muscles. Each muscle is intimately involved in the golf swing and is liable to injury. Outside of the rotator cuff, the strong deltoid muscle stabilises the shoulder and is an essential component in creating normal shoulder abduction during the golf swing. The pectoral muscles are also particularly involved in the golf swing in both the takeaway and downswing motion. The latissimus dorsi muscle is also a critical muscle for the initiation of the downswing. Each structure can be injured directly or in combination during the golf swing and this joint accounts for 10% of professional injuries and 12% of amateur golf-related injuries.

Elbow injuries are particularly common among amateur golfers where they account for a third of all injuries but less than 10% in the professional ranks. The elbow joint is a hinge joint formed between the humerus, the radius and the ulna. It can only be flexed and extended. During the golf swing it also pronates and supinates. Extensor and flexor tendons are inserted to the elbow. The extensor apparatus is located on the outside or lateral aspect of the elbow and the extensor tendon can frequently be injured. This injury is known as a tennis elbow but is in fact more common in the golfing population than its counterpart, the golfer's elbow. The flexor tendon is inserted into the inside or medial aspect of the elbow and inflammation of this area is referred to as a medial epicondylitis or Golfer's elbow. Unusually, a tennis elbow is more common than a golfer's elbow in the golfing population.

Other tendons can also be injured around the elbow and the triceps tendon can be injured directly due to trauma from poor impact with the ground or from overuse. In cases of chronic medial epicondylitis, the ulnar nerve can be compromised resulting in pins and needles into the 4th and 5th digit of the hand. In cases of poor playing technique, the supinator muscle can become inflamed. This lies just below the elbow joint. The radial nerve runs through this structure and if the muscle becomes hypertrophied or injured it can result in local entrapment of the radial nerve. This often results in sensory alteration in the 1st webspace of the hand and weakness in wrist extension. When the radial nerve and its branch (the posterior interosseous nerve) become involved the condition can mimic tennis elbow. In these instances, surgical release of the nerve is often required. This condition is often

referred to as "resistant tennis elbow" as the symptoms mimic the classical tennis elbow which is inflammation of the extensor tendon.
