This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Shoulder and arm injuries, Subject name: Orthopaedics
Lift -off test is done to assess the function of 
Select and explain. 
A. Supraspinatus muscle, B. Infraspinatus muscle, C. Teres minor, D. Subscapularis muscle
D: Subscapularis muscle
Answer: D: Subscapularis muscle 
Explanation: In this test,the patient is asked to stand and place one arm behind his her back with the dorsum of the hand resting against the mid-lumbar spine. The examiner then lifts the patient&;s hand off the back and the patient is told to hold it there. Inability to do this signifies subscapularis weakness,possibly due to rupture. A drawback is that the test calls for full passive internal rotation,so it cannot be used if internal rotation is painful or restricted. Ref: Maheshwari and Mhaskar 6e pg 95