Definition - What does extension of the shoulder mean?
Extension of the shoulder relates to the free movement of the upper arm lowering from a raised position in front of the body allowing the entire extremity to return to a normal resting posture at the waist and continuing behind the body permitting limited movement of the arm behind the back. Extension of the shoulder occurs at the glenohumeral joint, also referred to as the shoulder joint, incorporating coordinated action from various muscles connecting the shoulder girdle in order to execute smooth and fluid range of motion.
SureHire explains extension of the shoulder
Extension of the shoulder refers to lowering the entire arm from a flexed, or raised position, until the limb is in alignment with the hips and beyond the body, which permits the arm to perform limited range of motion behind the back.
Shoulder extension involves the interrelated function of several muscles including the latissimus dorsi, teres major, posterior deltoid, triceps trachii, and teres minor attached at the glenohumeral joint (shoulder joint) contracting simultaneously to bring the arm downward.
Although, the shoulder joint is demonstrably versatile in terms of executing multi-directional action, it is highly susceptible to injuries, in particular, biceps tendon tears. This type of injury is relatively common, especially among men, often resulting from one of two primary causes including lifting cumbersome objects or people reflexively catching themselves with extended arms (arms behind their body) to cushion a hard fall.
Consequently, the biceps brachii tendon, which unites muscles and bones separates either partially or totally, inducing moderate to severe pain while imposing range of motion constraints which, in turn, minimizes physical activity. A trained clinician can assess shoulder extension via standardized measurements to determine its normal range of motion throughout the recuperation process.