The human body is all about moving forwards! The majority of our powerful muscles at the back of the body, the triceps is no exception. A tripartite muscle, the triceps has a longer middle portion (the long head) and shorter side portions – the medial and lateral heads. All of these positions unite together to form a common tendon which inserts into the olecranon process of the Ulna bone.
The long head starts at the infraglenoid tubercle of scapula. The lateral head: begins upper half of posterior surface of shaft of the humerus (above and lateral to radial groove). The medial head originates in the lower half of posterior surface of shaft of humerus (below and medial to radial groove). Trigger points can develop in any or all of the three heads of the triceps muscle. Trigger point pain maps for the triceps muscle varies according to which of the heads is mainly affected. (a) Long head: pain at superolateral border of shoulder, radiating diffusely down posterior upper extremity with strong zone of pain around olecranon process, and then vaguely into posterior forearm; (b) medial head: 5cm patch of pain in medial epicondyle, radiating along medial border of forearm to 4th and 5th digits; (c) lateral head: strong midline pain into upper extremity, radiating vaguely into posterior forearm.
MUSCLE COMMENT
The Triceps is the only muscle at the back of the arm. The long head passes between the Teres minor and Teres major muscles on its course. Long head triceps tendinopathy does not appear extensively in the literature BUT we commonly find trigger points in the Triceps in certain presentations of adhesive capsulitis (frozen shoulder syndrome) that have an onset of reaching above the head (putting a bag in an overhead locker for example) or having an onset after pulling down weights from above the head. Trigger points in the Triceps muscle are also common after repetitive activities such as hammering, throwing or heavy lifting.