There are many different muscles, bones, and ligaments that create the shoulder joint. The bone structures that create the shoulder joint are the scapula, clavicle, and the humerus. It is important to consider that every muscle that passes over a joint, then plays a role in moving and stabilizing that joint. There are many muscles of the shoulder that are commonly known to play an imperative role in shoulder stability such as the rotator cuff muscles, but there are a few that are less commonly regarded when discussing shoulder stability such as the long head of the triceps.
The primary action of the long head of the triceps is to extend the lower arm at the point of the elbow, and they are often only known for this action. However, if you look for carefully at triceps, you can identify the point of origin falls on the scapula, causing it to play a role in stabilizing the shoulder. The long head of the triceps
originates right above the connection between the humerus and the glenoid fossa in a spot called the infraglenoid tubercle. The origin of the long head of the triceps is imperative in understanding why an undiagnosed triceps injury may lead to a shoulder problem down the road.
Pain that comes from a certain region of the body, without the appearance of acute trauma, is often the residual effect of a compensation. For example, shoulder pain or weakness can be cause due to an abnormality or injury at the elbow. Due to the triceps origin at the shoulder and insertion below the elbow, an elbow injury can caused substantial inhibition and pain in the shoulder.
Another muscle that plays a minute but important role in stabilizing the shoulder is the long head of the biceps brachii. The biceps brachii serve as the antagonist, the opposing muscle, to the triceps. The long head of the biceps plays a role in shoulder stability due to its point of origin being located in the shoulder at the supraglenoid tubercle. The long head of the biceps prevents the humerus from moving too far posteriorly with the force produced by different muscles such as the posterior deltoid, rhomboids, and triceps. Meanwhile, in contrast to the biceps, the triceps make sure that the humerus is not able to move too far anteriorly due to the force of muscles such as pectoralis major, pectoralis minor, latissimus dorsi, and many more.
Taking a deeper look into shoulder stability illuminates the way that, more often than not, tissue damage is not localized to where a patient may feel pain. An issue may arise in one location, but cause inhibition somewhere else triggering a compensative injury to transpire. Furthermore, shoulder stability identifies the crucial role smaller muscles play in maintaining proper movement such as the rotator cuff muscles and the often overlooked long head of the biceps and triceps.