The teres major muscle runs from your shoulder blade to your arm bone and lies directly beneath the teres minor. An injured teres major muscle makes it difficult to pull objects toward you, close the trunk of your car or to do pull-down exercises in the gym. To strengthen the teres major after an injury, begin with flexibility exercises once pain and swelling of your injury have subsided.
The first thing you should do prior to beginning your flexibility exercises for the teres major muscle is to apply a hot pack on the posterior border of your underarm. The hot pack should cover the most lateral aspect of your shoulder blade, and the posterior and inferior bend of your shoulder. Heat increases the temperature of your teres major muscle, which makes it more flexible and in turn, decreases pain. The less pain you experience during your rehabilitation exercises, the more likely you are to complete your program and strengthen your muscle.
Repetition and Time
There are passive and active flexibility exercises you can do to strengthen your teres major. A passive stretch uses simply the weight of your arm to stretch your teres major while you are otherwise relaxing. Active stretches require you to pull or push on your arm to stretch your muscle. You should perform just one passive stretch per stretching session, but hold the stretch up to 15 minutes. You can perform active stretches for up to four repetitions, holding each stretch for 15 seconds per repetition. You should include two to three stretching sessions in your daily routine, every other day.
The function of the teres major muscle is to pull your arm back down when it is raised above you. To passively stretch the teres major, you must move your arm in the opposite direction. To perform the lying abduction stretch, lie on your uninjured side with your head close to the end of a bed or flat exercise bench. This enables you to hang your arm to stretch your teres major. Place a pillow underneath your head for comfort. Perform this stretch by resting comfortably on your uninjured side, and then drape your injured arm over your head, keeping your upper arm near your ear. You should feel the stretch across the back side of your shoulder joint, directly across your teres major muscle. Hold the stretch for five minutes initially, adding five more minutes for subsequent sessions.
The horizontal flexion stretch is an active stretch, which you may perform either standing up or sitting down. To complete this stretch, draw the straightened arm of your injured teres major across the front of your body. Your arm should run at a diagonal from your shoulder joint, across the front of your neck with your elbow between the level of your uninjured shoulder and your chin. Hold the stretch for 15 seconds then relax and repeat.