Serratus anterior dysfunction examination: wall push-up or shoulder flexion resistance test?

Area of Science:

• Orthopedics
• Sports Medicine
• Physical Therapy

Background:

• Scapular winging, often due to serratus anterior dysfunction, is commonly diagnosed using the wall push-up test (WPUT).
• The WPUT may lack specificity in differentiating causes of scapulothoracic abnormal motion (STAM).
• A novel maneuver, the shoulder flexion resistance test (SFRT), is proposed to improve diagnostic accuracy.

Purpose of the Study:

• To evaluate the diagnostic accuracy and specificity of the novel shoulder flexion resistance test (SFRT) for serratus anterior dysfunction.
• To compare the efficacy of SFRT against the traditional wall push-up test (WPUT) in diagnosing STAM.
• To determine if SFRT can reliably identify serratus anterior dysfunction as the cause of STAM.

Main Methods:

• Fifty patients with STAM underwent clinical scapular examination using both WPUT and SFRT.
• SFRT involves resisting shoulder flexion at specific degrees (30°, 60°, 100°) with the elbow extended.
• Preoperative electromyography and intraoperative stimulation of the serratus anterior were performed, correlating findings with clinical tests.

Main Results:

• The WPUT showed 100% sensitivity but 0% specificity for serratus anterior deficiency, with 45 false positives.
• The SFRT demonstrated 100% sensitivity and 100% specificity for serratus anterior dysfunction as the cause of STAM.
• Receiver operating characteristic (ROC) analysis indicated excellent accuracy (AUC 1.0) for SFRT versus clinically insignificant accuracy (AUC 0.5) for WPUT.

Conclusions:

• The shoulder flexion resistance test (SFRT) is a specific and accurate diagnostic tool for serratus anterior dysfunction causing STAM.
• SFRT should be considered the preferred physical examination method over WPUT for evaluating serratus anterior muscle dysfunction.
• Accurate diagnosis with SFRT can better guide operative management strategies for STAM.