The teres major (L. teres, round and long ; major, larger.) is a thick, rounded muscle in the posterior shoulder region. It acts on the shoulder joint, with its main function as a synergist in shoulder adduction.
It is classified as a one of the scapulohumeral (intrinsic shoulder) muscles, and is visible on the surface of the physique…
Posterior surface of the inferior angle of the scapula
Medial lip of the intertubercular groove of the humerus
Shoulder internal rotation
Lower subscapular nerve (C5-C7)
Note: The following table includes the exercises that most directly target teres major. These are also latissimus dorsi exercises, since the teres major works synergistically with the lats when acting on the shoulder joint.
Overactive/Short Teres Major: The teres major is overactive and short in people with upper crossed syndrome (UCS). The shoulder internal rotation associated with UCS facilitates the teres major, which causes reciprocal inhibition of the external rotators. The overactive/short teres major can limit overhead range of motion, as its inability to stretch sufficiently will physically restrict the upper arm from elevating past a certain point. The initial cause of the teres major overactivity is often a combination of poor postural habits (i.e. arms in, hunching over) and an excessive focus on lat exercises and, to a lesser extent, chest exercises.
If your teres major is overactive/short, do the following:
Reduce your training volume on teres major exercises and lat exercises.
If your overhead range of motion is limited, avoid vertical push exercises like the overhead press. Do high-incline push exercises instead (e.g. shoulder press on 60-75° incline). This way, you can still train the front delts with heavy weight but avoid injury by staying within a safer range of motion.
Perform teres major releases/stretches on a daily basis, ideally as part of a more comprehensive mobility routine. These techniques should also be part of your warm up routine for workout involving any upper body lifts and lower body lifts that work the back or require shoulder mobility (e.g. deadlifts, squats, Olympic lifts).
Have good postural awareness. Avoid slouching over and internally rotating your shoulders. If you’re sitting down for long periods, get up for a quick break at least every half hour to split up the time spent in that posture. Walk around or stretch out your teres major (and any other tight muscles if you have time).
Do more exercises that involve shoulder external rotation, as opposed to shoulder internal rotation. Examples include: face pulls, prone cobra, any YTWL variations, Cuban press and shoulder external rotations.
If upper crossed syndrome is the cause of your teres major dysfunction, then you’ll need to address that with a more comprehensive approach than what is outlined above. See how to fix upper crossed syndrome (article coming soon) for a detailed plan.
If you want bigger teres major muscles, consider the following:
Although the teres major may be an important part of an aesthetic physique, it’s impossible to isolate them. It will grow incidentally from doing any horizontal or vertical pull exercise (i.e. any row or pull up/pulldown variations).