Monday, 31 March 2014

Infraspinatus : 1 of 4 rotator cuff muscles

INFRASPINATUS: the I in the rotator cuff acronym 'SITS':

Infra’ meaning ‘below’ and just like the last muscle Supraspinatus, SPINATUS referring to the spine of the scapula (shoulder blade)

So we now know that the INFRASPINATUS muscle lives below the spine of the scapula.

Official attachment points:   

originates at the infraspinatus fossa of the scapula * (crosses the shoulder joint) and inserts onto the MIDDLE facet of the greater tubercle of humerus.  (same attachment point as SUPRASPINATUS but just a different FACET**


ACTIONS:  Infraspinatus externally rotates your arm at the shoulder joint aka “lateral rotation (AWAY from the body) aka rotating your arm outwards (see video link for details!)

NOTE: INFRASPINATUS  muscle is often WEAK and OVER-STRETCHED on most people!  To strengthen them you simply need to do the action infraspinatus is responsible for: external rotation! Here is a video showing two ways you can do external rotation at the shoulder joint. 

To STRENGTHEN simply add a weight in your hand whilst doing the action!  No need to go out and buy a handweight, any ol' can in the cupboard will do! For strengthening move slowly to avoid injury. Try 10 reps for 3 sets or until you feel you've 'exhausted the muscle' REMEMBER: PAIN = BAD - SHAKING IS OKAY!

*once again an attachment point with the same name as the muscle yeah! It’s like Christine living on Christine Street!)

**You will soon see that all 3 out of 4 rotator cuff muscles’ attachment points INSERT at the same area; the greater tubercle of the humerus except just different FACETS (superior, middle,  & lesser)