While much more common in swimmers and triathletes due to overuse with the freestyle swim stroke, shoulder pain can affect anyone who performs a lot of overhead activities and is easily strained with awkward movements like lifting a child. Once present, pain can arise when pumping your arms while running or just sleeping on the effected side. Unfortunately, this is one problem that will not just "go away with rest" (are you listening men?) and requires the sufferer to take an active role for it to fully recover.

The shoulder joint has the greatest range of motion of any joint in the body. Anatomically speaking, when we gain mobility, we lose stability, and accordingly, the shoulder is the most unstable "joint" in the body. When I say "joint", I'm really talking about a complex unit made up of four joints or articulations which include movements of the humerus (upper arm bone), the shoulder blade, and the collar bone.

The "shoulder joint", where movement of the upper arm occurs, is a very shallow joint with very little stability created by bone to bone contact. Stability is produced primarily by a group of four small muscles called the "rotator cuff", and it's their job to keep the "head" of the humerus centered within its attachment to the shoulder blade (see figure 1).

The movements of these structures are complex and must be performed in a very coordinated fashion with all parts of the rotator cuff working together. As we move our arm overhead, a properly functioning rotator cuff pulls the humeral head down and into the joint, preventing it from rising up and making contact with the acromial arch (see figure 2). When this occurs it is called "Impingement Syndrome" and feels like a sharp pinching sensation at the top of the shoulder joint.

Typically, imbalances in the rotator cuff muscles allow the head of the humerus to ride forward and superiorly in the joint, towards that arch and subsequent impingement. This effect becomes more pronounced if we swim "flat", with too little body roll. Decreased body roll requires greater extension at the shoulder joint to allow the arm to clear the water. The longer this goes on, the tighter the posterior aspect (back) of the joint gets, so stretching out this area is where we need to concentrate our efforts.

Dr. Ken Sheridan is a local road and trail runner who competes in a variety of local events. He practices at Active Care Chiropractic and Rehab in Golden. To ask him your injury questions, call 303-279-0320.

1. Straighten your right arm and bring it across your chest, grabbing it under and just above the elbow with your left hand. Be sure to pull down and keep your shoulder blade from rising up towards your ear. You should feel the stretch right behind the shoulder joint. Repeat with the opposite side. (See figure 3)

2. With your thumb facing forward, bring your right arm straight up towards the side of your head, and bend your elbow, keeping your hand going straight backward. Reach over with your left hand and grab your right elbow, push backward. You should feel the stretch in the back of your armpit. (See figure 4 and 5)

Stretches should be performed four to six times per day, one repetition each time and held for 30 seconds. The following stretches have proven very effective in helping to rebalance the rotator cuff.