In-depth coverage of all of the possible posture deviations could be an entire book (and might just be) so for the purpose of this article series, I’m going to cover the most common two problems I see on a daily basis. That being said, without a personal evaluation, it is impossible to pinpoint exact problems, so think of this as a cursory screening to point you and or your clients in the right direction.

And the first deviation is…

1. Internally Rotated Humerus

The Problem

The head of the humerus bone should sit in the shoulder socket (glenoid cavity) in such a way that causes the palm to face directly towards the illiotibial tract in a relaxed position. Although this proper alignment is uncommon in today’s society of desk jobs and poor exercise habits, it is necessary for optimal shoulder health.

Internal rotation causes faulty neural recruitment patterns during pulling and pressing movements which can lead to chronic degeneration of external rotators (the rotator cuff musculature) and a perpetual chain of muscular imbalances.

So what the hell are faulty neural recruitment patterns? Using the Overhead Press as an example, most would consider it an exercise to train the “shoulders”. Some of the kinesiology savvy folks will take it a step further and realize that most of the tension will be on the medial deltoid, followed by the anterior deltoid (dependant on degree of arm abduction during the press), and to a lesser extent- the triceps, serratus anterior, and traps (the latter three contribute mostly from 90 degrees up).

A healthy shoulder girdle will fire not only the aforementioned prime movers in the proper order and force allocation, but it will also contract the smaller supporting musculature at the exact right time in conjunction with the bigger muscles to carry out the movement in the safest, most efficient manner. When a person has an internally rotated humerus, he/she will tend to perform an overhead press in an oblique plane, sliding saggitally anywhere from 5-20 degrees out of the proper coronal alignment (the press will terminate slightly in front of the body, instead of directly over the head). This is because the pecs and subscapularis muscles are chronically tight and shortened, and the rotator cuff (specifically the infraspinatus in this instance) lacks the strength and unimpaired innervation to pull the humerus back into proper coronal alignment.