Infraspinatus

Above is the pain pattern for the Infraspinatus. Pain refers from the front side of the shoulder downwards along the outside of the arm and upwards toward the back of the head.

Activities Which Aggravate the Pain
Zipping a back zipper, reaching backwards to put your arm in a shirt or jacket, washing your hair, sports activities that involve shoulder motions, shaking hands, placing luggage on the airline weighing platform.

Positions that Aggravate Pain from this Muscle
Sitting for long periods in narrow seats such as with air travel. This figure shows where the muscle is located in the body and how it is attached to the bones of the body.

Anatomy Facts - Infraspinatus

Muscle Action
Shoulder external rotation.

Muscle Origin
Arises from the medial two-thirds of infraspinatus fossa.

Muscle Insertion
Inserts onto the middle impression on the greater tubercle of the humerus.

Muscle Innervation
From the suprascapular nerve.

Trigger Point Locations - Infraspinatus

You can find your own trigger points by using your thumb or finger to press on the spots shown in the picture. They are not difficult to find. Or you can ask a friend or family member to help you. Press firmly in a step-by-step manner until you find the exact spot that is tender. That is the trigger point.

By pressing firmly on the trigger point, and holding that pressure for several seconds, you will discover the pain lessens dramatically. In fact there are devices that can help you do this. We recommend a device called a "TheraCane" that can be purchased at many stores such as Sammons Preston Medical Equipment that has a mail order catalogue that can be contacted at 1 800 323-5547. The TheraCane is their item # 5244. The TheraCane can use be purchased at many local pharmacies.

Unfortunately this technique, known as acupressure, or shiatsu, provides only temporary relief. Some physicians inject drugs like Novocaine into trigger points, but these offer only temporary relief as well, and can cause scar tissue in the muscle.

Isometric Contraction Testing - Infraspinatus

A painful muscle will become more painful if it is forcefully contracted (flexed). Use this picture to test this for yourself with the help of a friend or family member.

Follow these Directions
Sit with the painful-side elbow raised out to the side at shoulder height and your hand dangling down in a "scarecrow" position, while your assistant places one hand under your elbow and the other against the back of your wrist and forearm. Attempt to swing your forearm frontward and upward toward the "under-arrest" position while your assistant prevents this movement.