by Dr. Richard Beauchamp, M.D., FRCSC
Among runners and walkers, arm injuries are much less common than leg injuries. Even so, an injury to the arm or shoulder can be debilitating—anyone who has experienced the pain of inflammation around the shoulder knows what I mean. An athlete can cope with a leg injury by limping, using crutches, elevating, sitting, or lying down. In contrast, it is very difficult to “rest” an arm joint such as the shoulder or elbow. Even standing and sitting can require the arm musculature to contract, often resulting in pain. You just can’t “get away” from arm pain quite as easily.
Since runners pound the pavement so hard and so repetitively, it is a natural assumption that injuries would be confined to their legs. Runners’ legs have to contend with an inordinate amount of force—up to three or four times their body weight. These forces have to be absorbed by the body, thus injuries can occur in the legs, as well as up the skeletal structure to the back, neck and arms.
Arm injuries, however, are not simply confined to the transmission of forces from running and landing on the ground. The arms provide other functions during the running cycle, such as providing momentum for the runner. This action to generate force can be responsible for arm injuries in runners, as seen in other sports such as swimming, javelin, baseball and archery.
The part of the arm most affected in sports injuries is the shoulder, which is a potentially unstable joint. Unlike the ball-and-socket joint of the hip, the shoulder relies mainly on ligaments and tendons to provide stability, which means it can be more easily dislocated.
Shoulder dislocations and fractures usually occur with macro-trauma—for example, when a runner trips and instinctively uses his arm(s) to break the fall. The force transmission through the arm pushes the shoulder out of its joint, resulting in either a shoulder dislocation or a broken bone. Unless shoulder dislocations have occurred frequently in the past, the runner will usually require medical attention to put the shoulder back in the joint (also called “reducing”).
The more frequent injury sustained by the shoulder, however, is not from major trauma, but rather from inflammation or degeneration. Tendonitis, bursitis, impingement syndromes, and rotator cuff tears are all examples of repetitive movements that result in “wear and tear” of the joint structures, leading to inflammation, pain and disability. Various terms such as bicipital tendonitis, sub-acromial bursitis and calcific tendonitis refer to the actual anatomical and pathological effects at the shoulder. These injuries produce shoulder pain, which may occur with arm swing while running. Just as the legs go through 25 to 30 thousand steps during a marathon, the arms also swing the same number of times. Often, the pain is felt after running has ceased and daily activities are resumed. Movements such as overhead reaching can produce immediate pain around the shoulder if it is inflamed. The runner may have a “painful arc” syndrome where they have to rotate their arm in a peculiar fashion in order to raise or lower it without pain. There may be situations where the rotator cuff is so damaged that it is impossible to raise the arm more than a few degrees from the side of the body.
Treatment for “runner’s arm” starts with the individual runner. The amount of pain and disability found in the shoulder usually dictates which treatment options to pursue. Minor aches and pains may only require a period of rest and the application of ice to the shoulder several times a day for 15 to 20 minutes per session. Strengthening the shoulder girdle muscles through arm exercises (including weight lifting) may also be part of the solution.
When there is more significant pain and limited movement (or when there is a lot of shoulder pain at night), further investigation and treatment may be required. An x-ray may reveal a bony injury, which may require surgery. Calcification in the tendons around the shoulder may also be seen on an x-ray. Sometimes this calcification can be from inflammation or from tissue degeneration. In either case, a steroid injection administered by a doctor may be beneficial to diminish the inflammation and allow the shoulder to be exercised, stretched and strengthened with less discomfort. The goal here is to stop the continuing cycle of lack of movement, resulting joint stiffness, and pain.
Thoracic outlet syndrome occurs from excessive pressure on the nerves and blood vessels as they leave the neck and run over the ribs to descend down the arm. The runner can complain of numbness in some of the fingers of the hand with a feeling of heaviness or discomfort in one or both of the upper extremities around the base of the neck and shoulder girdles. The symptoms can sometimes be relieved, at least temporarily, by supporting the arms on a chair railing or by just resting. In these cases, an exercise program to strengthen the shoulder girdle and neck muscles is needed. Sometimes, further tests of the nerves and blood vessels are required and may reveal the need for surgery.
Carpal tunnel syndrome (CTS) occurs when a nerve to the hand, the median nerve, gets compressed as it passes through an anatomical tunnel at the wrist. The runner may complain of finger numbness, and may be especially prone to CTS if running causes the hands and fingers to swell with arm swing. There may also be pain and finger tingling that awakens the runner at night. Sometimes a wrist splint supports the hand to avoid excessive compression of the median nerve. Occasionally, surgical release of the tunnel is required.
These examples of arm disorders or injuries can occur in non-runners as well as runners. Maintaining adequate strength and flexibility in the arms should be considered as important as for the legs. As with all injuries, if the symptoms do not improve after a few weeks of self-treatment or rest, the athlete should seek further assistance in managing the condition. A visit to your physiotherapist or family doctor is then indicated.
Dr. Richard Beauchamp is an orthopedic surgeon based in Vancouver. He is the medical director of the Shriner’s Gait Lab at Sunny Hill Health Centre and a clinical professor in the Department of Orthopedics at the University of British Columbia. He is an avid runner and walker who has completed seven marathons.