The triceps muscle connects to the shoulder via its long head, which originates from the infraglenoid tubercle of the scapula.
The triceps brachii, as the name implies, is a three-headed muscle located on the posterior aspect of the upper arm. Only one of these heads, the long head, crosses the shoulder joint. The other two heads, the lateral and medial heads, originate from the posterior humerus and only act on the elbow joint.
Here's a more detailed breakdown:
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Long Head Origin: The long head of the triceps originates from the infraglenoid tubercle of the scapula. This tubercle is a small bump located just below the glenoid fossa (the socket that articulates with the head of the humerus to form the glenohumeral joint, or shoulder joint). Because the long head originates from the scapula, it is able to influence movement at both the shoulder and elbow joints.
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Triceps Function: While all three heads of the triceps extend the elbow, the long head also contributes to shoulder extension and adduction due to its origin on the scapula.
In summary, the triceps muscle connects to the shoulder through the long head, which originates from the infraglenoid tubercle of the scapula. This allows the triceps to influence both shoulder and elbow joint movements.
