Patient is able to abduct, internally rotate and take his arm upto lumbosacral spine but not able to lift off. What is the probable diagnosis
**Core Concept**
The patient's inability to lift their arm off the lumbar spine, despite being able to abduct and internally rotate it, suggests an issue with the shoulder joint's function, particularly the relationship between the glenohumeral joint and the scapula. This scenario points towards a problem with the scapulothoracic movement and possibly a deficiency in the serratus anterior muscle.
**Why the Correct Answer is Right**
The patient's symptoms indicate a weakness in the muscles responsible for upward rotation and scapular protraction, which are primarily the function of the serratus anterior muscle. This muscle plays a crucial role in the scapulothoracic movement, allowing for the scapula to rotate upward and move forward, enabling the arm to be lifted off the lumbar spine. The inability to perform this movement suggests a probable diagnosis of Serratus Anterior Palsy.
**Why Each Wrong Option is Incorrect**
**Option A:** This option might be considered if the patient had difficulty with abduction or internal rotation, but the patient's ability to perform these movements suggests that the issue lies elsewhere.
**Option B:** A rotator cuff injury would more likely result in pain and weakness with abduction, rather than a specific inability to lift the arm off the lumbar spine.
**Option C:** A frozen shoulder would result in pain and stiffness in the shoulder joint, but it would not specifically cause an inability to lift the arm off the lumbar spine.
**Option D:** This option might be considered if the patient had difficulty with shoulder flexion or extension, but the patient's ability to abduct and internally rotate the arm suggests that the issue is more specific to scapular movement.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that a patient's inability to lift their arm off the lumbar spine, despite being able to abduct and internally rotate it, is a classic sign of Serratus Anterior Palsy. This condition often results from a nerve injury, such as a long thoracic nerve palsy, which can be caused by trauma, surgery, or even a minor injury.
**Correct Answer:** C.