The infraspinatus is one of those muscles that often gets neglected and misused, but needs great attention and care. Originating at the infraspinous fossa of the scapula and inserting at the middle facet on the greater tuberosity of the humerus, the infraspinatus does the important job of laterally rotating the arm at the shoulder while holding the humeral head in the glenoid cavity of the scapula.
This important rotator cuff muscle is a prime mover (the agonist or muscle that contracts) in adduction and external rotation, which means that if there is too much adduction and external rotation, this muscle will be overworked and literally be in agony. If there is too much abduction and internal rotation, this muscle can be overstretched and can lead to injury and overuse. So, what is the solution? “Balance” and “everything in moderation” may sound cliché, but they are mantras when it comes to keeping your infraspinatus healthy and vibrant.
Before we get into fun ways to Tune Up your infraspinatus, here’s some serious information you need to know for optimal care of this essential muscle. When the infraspinatus does its job well and externally rotates the humerus, it draws the greater tuberosity away from the acromion. This prevents a condition called impingement, which involves compression of the subacromial bursa between the greater tuberosity of the humerus and the acromion, resulting in shoulder pain.
Our electronically charged society where texting anytime, anywhere, is the thing to do, along with driving (not to mention texting while driving) and sitting endlessly at a computer, brings the shoulders in a position of prolonged internal rotation. The last time I got my hair cut at the salon, I was surprised to see so many women holding their iPhones overhead and texting while they were having their hair washed. Prolonged internal rotation while the arms shoulders are in flexion is not a happy position for the infraspinatus. Maybe if these women read this blog post they will try to care as much for their muscles as their hair.
On Friday I’ll share a Yoga Tune Up® pose that will help you build a strong and supple shoulder!