Reduce Injury Risk when rock-climbing

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External Rotation. This simple exercise, done with a 2.5 or 4.5kg  (5 or 10 lb)  dumbbell, will help strengthen your rotator cuff...and perhaps make you more bullet-proof on shoulder-wrenching climbing moves. While climbing provides a rigorous workout for the pull muscles, it demands much less of the antagonist push muscles of the chest, shoulders, and upper arms. In the long term this could lead to tendinitis or other injuries, as these stabilizing push muscles may fall out of balance with their opposing pull muscles. The two most common problem spots are the elbows and shoulders. Let’s take a quick look at each. First, consider how climbing ceaselessly works the finger-flexor muscles of the forearms, yet does little to strengthen the extensor muscles on the outside of your forearms. As a result, climbers tend to develop a significant muscular imbalance and a susceptibility to lateral epicondylitis—a painful tendinitis on the outside portion of the elbow (also known as tenni...

Beginning End The most effective is the side-lying external rotation, which activates the supraspinatus, subscapularis, infraspinatus and teres minor. Lie on a bench sideways, with the arm next to the side and flexed about 90 degrees at the elbow. Rotate the upper arm, raising the dumbbell towards the ceiling to a 45 degree angle. Keep the elbow flexed, and the upper arm close to the body. Pace at  two  seconds up and  four  seconds down. This is an excellent all-around shoulder exercise. (from  http://en.wikipedia.org/wiki/Rotator_cuff#Muscles_composing_rotator_cuff , Read its discussion also.)

Beginning End This propped external rotator targets the infraspinatus and teres minor. Sit perpendicular to the barbell with arm flexed at 90 degrees at the elbow, and the forearm resting parallel on the barbell. Raise the dumbbell up until the forearm points up. Slowly lower the dumbbell and repeat, exercising both arms. The posterior deltoid also aids in external rotation. Like the posterior deltoid, both the infraspinatus and teres minor also contribute to transverse extension of the shoulder, such as during a bent over row to the chest. They can be trained in this way besides isolating the external rotation action.

Beginning End The lateral raise with internal rotation (LRIR) primarily targets the supraspinatus. Grasping a dumbbell in each hand, internally rotate the arms so that the thumbs point towards the floor when extended (as if emptying a drink into a bin). Raise the arms sideways, keeping the thumbs pointing downwards, until the dumbbells are just below the shoulders. This exercise is sometimes called a lateral raise.