Throwing places a lot of stress on the shoulder and elbow joints in particular. Throwing is a major component of many sports such as baseball, netball and basketball as well as a number of athletic events such as discus, shot putt, javelin and hammer.
The strength of the shoulder joint and shoulder girdle as a whole is important in avoiding shoulder injuries when throwing. All shoulder, chest and back muscles should be strengthened in their respective groups, but should also be strengthened together as a unit, as this is how they work whilst throwing. Exercises using medicine balls are great for increasing a players throwing strength. The muscles should also be strengthened eccentrically (a contraction where the muscle lengthens to control a movement) as eccentric contraction occurs when decelerating the arm during follow through. Catching medicine balls in various ways and the use of resistance bands are excellent for this.
The flexibility of the upper limb muscles can be important in avoiding injury. The shoulder must pass through a full range of motion when throwing and so being flexible will help with being an efficient thrower. The more efficient the throw, the less chance of injury.
Warming the arm, shoulder girdle, chest and back is important before beginning a throwing session. A cardio warm-up should be performed to increase core body temperature and heart rate. This should be followed by active stretches for the upper limb, such as shoulder circles and shrugs. Always start with the smallest movement and gradually increase the range as the muscles warm-up and increase in elasticity. Static stretches for the shoulder, upper back and chest can also be used. Once a warm-up is completed, do not go full out on your first throw! Start with low effort throws with an emphasis on technique.
Rotator cuff injuries
The rotator cuff are a group of four muscles which attach to the scapula (shoulder blade) and help to stabilise the shoulder joint and produce rotation movements. Any of the rotator cuff muscles can be torn during a strong twisting motion, although the most common are the supraspinatus and infraspinatus. Other problems include tendonitis which is an overuse injuries that develops gradually over a period of time. It presents as pain in the shoulder, especially when lifting the arm out to the side or rotating the shoulder. If left untreated this can cause the tendon to rupture. Learn more about rotator cuff injuries.
Glenoid labrum injuries
The glenoid labrum is a ring of cartilage which surrounds the socket of the shoulder joint. It acts to increase the depth of the socket and so stability of the shoulder joint. The Bicep tendon attaches in part to the labrum and so when throwing, a strong contraction of the biceps causes a pull on the labrum which can result in a tear. Pain usually presents on the 'cocking' phase and the follow through phase, at the back of the shoulder. A torn labrum can place extra strain on the rotator cuff and result in another tear to one of these muscles. Find out more about labrum injuries.
Repeated throwing year after year can cause the ligaments surrounding the shoulder to stretch. If the rotator cuff muscles are not strong enough to support the shoulder it becomes lax and unstable. The symptoms of pain and a lack of speed during the throw are symptoms which are caused by the humerus slipping slightly off centre during the throw. Rehabilitation to strengthen the rotator cuff may be effective in less severe cases, but surgery may be required. Learn more about shoulder instability.
Collateral ligament injury
The medial collateral ligament is the ligament which runs on the inside of the joint, connecting the humerus (upper arm bone) and ulna (larger of the two forearm bones). Injuries to this ligament sustained through throwing are normally overuse injuries, caused by the repetitive throwing action, as opposed to a direct rupture caused by a force to the elbow. The ligament tends to become stretched and then gradually tear a little more with each throw, almost like a rope fraying. Pain will gradually increase until throwing is no longer possible. Find out more about collateral ligament injuries.
The muscles of the forearm which act to flex the wrist and fingers attach to the medial epicondlye on the inside of the elbow. Repetitive wrist flexion, pronation and gripping are all important features of throwing activities. With repetitive use, the common tendon of these muscles can become inflamed and painful at the point where it attaches to the bone. In severe cases the tendon may develop small tears, although it rarely ruptures completely. Learn more about golfers or throwers elbow.