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Updated: Jan 12, 2026
Manual Muscle Testing: A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients
Published on: April 12, 2011
Zero vs. 30: a diagnostic manual muscle testing technique for detecting full- or partial-thickness supraspinatus
Misty Suri1, Arjun Verma1, Justin Kim1
1Department of Orthopedics and Sports Medicine, Ochsner Hospital for Orthopedics & Sports Medicine, New Orleans, LA, USA.
Background:
Rotator cuff tears (RCTs), either full-thickness (FT) or partial-thickness (PT), are a common pathology encountered in clinical practice. Magnetic resonance imaging is the imaging modality of choice to evaluate rotator cuff pathology but can lead to overdiagnosis. A thorough physical examination is necessary, supplemented by an magnetic resonance imaging to confirm diagnosis. This study describes an empty can (EC) test with scaption at 0°. Our hypothesis that this method has a higher diagnostic value compared to the conventional EC test in diagnosis of RCTs.
Methods:
A retrospective review of evaluation of patients presenting with rotator cuff symptoms by a single fellowship-trained surgeon was done. A total of 117 shoulders presenting between August 2020 and March 2021 were included. Using the standard Medical Research Council Manual Muscle Testing scale, EC test was graded at 0° and 30° scaption. Sensitivity, specificity, and overall accuracy were calculated for the EC test at scaption 0° and 30°.
Results:
For FT-RCT, sensitivity and specificity were 88.9% and 24.7% for EC-scaption 0°, and 38.9% and 62.9% for EC-scaption at 30°. For PT-RCT, sensitivity and specificity were 82.5% and 23.5% for EC-scaption 0°, and 38.6% and 63.2% for EC-scaption 30°. For either thickness, sensitivity and specificity were 92.5% and 59.4% for EC-scaption 0°, and 47.3% and 90.6% for EC-scaption 0°.
Conclusion:
This study highlights that the EC at 0° scaption is more sensitive compared to the EC at 30° scaption for diagnosing RCTs. The EC test at 0° scapular plane shows higher sensitivity and overall accuracy than EC at 30° scaption for FT-RCTs and/or PT-RCTs.
