肩試験 II
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Q1: What are the four rotator cuff muscles and what do they do?
The rotator cuff consists of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. These muscles function as compressors, holding the humeral head firmly in place against the glenoid. Together, they stabilize the shoulder joint and enable controlled arm movement during physical activity.
Q2: How does strength testing help identify rotator cuff problems?
Strength testing involves applying resistance to specific shoulder motions while the examiner observes the patient's response. Pain during resisted motions suggests tendonitis, while weakness indicates a possible rotator cuff tear. This differentiation helps clinicians determine whether the problem is inflammatory or structural.
Q3: Why is bilateral comparison important in shoulder examination?
Comparing both shoulders allows clinicians to establish a baseline and identify abnormalities more accurately. The uninjured shoulder serves as the standard for evaluating the injured shoulder, provided it has not been injured as well. This side-to-side comparison improves diagnostic accuracy and helps detect subtle differences in strength or range.
Q4: What conditions does the shoulder exam II assess beyond rotator cuff strength?
After rotator cuff strength testing, the examiner tests for subacromial pain syndrome, shoulder instability, and labrum injury. These additional assessments provide a comprehensive evaluation of shoulder pathology. Together with strength testing, they help identify the specific source of shoulder pain and dysfunction.
Q5: Why are rotator cuff injuries the most common source of shoulder pain?
Injury and degeneration of the rotator cuff tendons are the most common sources of shoulder pain because these muscles are essential for stabilizing and moving the shoulder joint. The rotator cuff endures significant stress during daily activities and sports. Overuse, aging, and trauma can damage these tendons, leading to pain and functional limitations.
Q6: What is the difference between pain and weakness in resisted shoulder motions?
Pain with resisted motions typically indicates tendonitis, an inflammatory condition of the rotator cuff tendons. Weakness during the same motions suggests a rotator cuff tear, representing structural damage to the muscle or tendon. This distinction guides treatment decisions and prognosis for the patient.
Q7: How does the shoulder exam II build on the initial shoulder examination?
Shoulder Exam II focuses on strength testing and specific pathology assessment, following the foundational shoulder exam palpation and range of motion evaluation. This progression allows clinicians to systematically assess shoulder function and identify dysfunction. The comprehensive two-part approach ensures thorough evaluation of all shoulder structures.