Final answer:
Weakness in shoulder abduction and ER, combined with a square shoulder deformity, are indicative of a potential rotator cuff or other shoulder injury. This condition requires an assessment of shoulder functionality which includes testing for abduction and external rotation, which involve muscles like the supraspinatus for abduction and the infraspinatus for lateral rotation. A personalized physical therapy plan can help in treating and restoring shoulder function.
Step-by-step explanation:
Shoulder injuries are commonly associated with activities that involve repetitive upper limb movements like throwing, swimming, or racquet sports, leading to varying degrees of pain, reduced mobility, and conditions such as adhesive capsulitis or "frozen shoulder". The rotator cuff is particularly susceptible to injury due to its crucial role in shoulder movement; involving the tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor which form a musculotendinous cuff around the shoulder joint, allowing for a broad range of motion. Shoulder dislocations often occur inferiorly because the humeral head is well supported by muscles and ligaments except at its inferior aspect. If someone is experiencing weakness of shoulder abduction and external rotation (ER) along with a square shoulder deformity, this could indicate a rotator cuff injury or another type of shoulder pathology, necessitating a thorough assessment by a healthcare provider and possible referral to physical therapy for a personalized treatment plan to restore shoulder function.
To assess shoulder functionality, including the ability to abduct and externally rotate, a physical therapist would start by evaluating the range of motion and muscle strength. For example, the supraspinatus muscle is responsible for the initial phase of arm abduction, whereas the deltoid muscle participates in abduction beyond that point. Lateral rotation is accomplished by the infraspinatus and teres minor. Any alterations in the normal strength or movement of these muscles could point to specific areas of concern within the shoulder complex. The therapist would then design an appropriate rehabilitation program to address the identified issues.