What does the "lift off test" assess specifically?

The "lift off test" specifically assesses the integrity and function of the subscapularis muscle, which is one of the four rotator cuff muscles located in the shoulder. This test evaluates the ability of the patient to internally rotate the arm behind their back and lift it off, which largely depends on the subscapularis muscle's strength and integrity.

When the subscapularis is functional, a patient should be able to perform the lift off maneuver, indicating that the muscle is intact and capable of creating the necessary force. If there is a tear or significant dysfunction, the individual will likely be unable to lift the arm off the back, which supports the diagnosis of a subscapularis tear.

Other options may assess different conditions but do not specifically correlate with the lift off maneuver. For example, rotator cuff tears would involve a broader set of tests to assess overall rotator cuff function, and ankle stability or wrist fractures would involve entirely different examinations. Thus, the lift off test is particularly focused on identifying issues with the subscapularis, making it the right answer.