Triceps Long Head Proximal Tendon

tendo proximalis capitis longi musculi tricipitis brachii

The long head of triceps has a proximal tendinous origin from the infraglenoid tubercle of the scapula, passing through the posterior axilla between teres major and teres minor before joining the triceps muscle belly in the posterior upper arm. This long intramuscular tendon is the proximal tendon of the long head.

Region: Upper Arm

Clinical Relevance

Clinical Notes

The long head triceps proximal tendon is vulnerable to injury during posterior shoulder dislocation and after proximal humeral fractures that extend to the infraglenoid region. Quadrilateral space syndrome involves compression of the axillary nerve and posterior circumflex humeral artery in the space bounded by the long head of triceps medially. MRI demonstrates proximal tendon signal change in triceps long head strain from overhead throwing.

Pathology

Common Injuries & Conditions

Triceps Long Head Proximal Strain

Traction injury at the infraglenoid origin producing posterior shoulder and upper arm pain reproduced by resisted elbow extension from the overhead position, identified by MRI as signal change at the proximal long head tendon.