The Four Rotator Cuff Muscles
The four rotator cuff muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis. The infraspinatus and teres minor muscles are placed on the back of the scapula, whereas the supraspinatus muscle is on the upper half of the scapula. The subscapularis muscle is situated below the subscapular fossa on the anterior aspect of the scapula.
The Rotator Cuff Muscle Most Commonly Injured
The supraspinatus muscle is most likely the rotator cuff muscle injured, according to the case study’s descriptions of the symptoms and orthopedic testing. Due to the supraspinatus muscle’s passage through a restricted area between the humerus (upper arm bone) and the acromion (part of the shoulder blade), a bony protrusion on the scapula, injuries to this muscle are particularly common.
Functional Actions of the Four Rotator Cuff Muscles
While the infraspinatus and teres minor muscles are in charge of the arm’s external rotation, the supraspinatus muscle starts the arm’s abduction motion. The subscapularis muscle helps stabilize the shoulder joint and is responsible for internal rotation of the arm.
Ligaments Connecting the Humerus and Scapula
The glenohumeral ligaments and the coracohumeral ligament are the two main ligaments that connect the humerus to the scapula. The humerus is joined to the glenoid fossa of the scapula by a trio of glenohumeral ligaments. The larger tubercle of the humerus and the coracoid process of the scapula are joined by the coracohumeral ligament. These ligaments keep the humerus from dislocating by stabilizing the shoulder joint.
Case Summary and Analysis
One can review the following case example: while playing catch with his son, Jason, a former baseball player, felt a severe ache in his right shoulder. Over the weekend, the discomfort persisted and worsened, so he visited the doctor. A moderate to severe right rotator cuff strain and a moderate shoulder sprain resulted from the sports medicine physician’s assessment.
If symptoms persist beyond two to three weeks, the physician recommends proceeding with physical therapy and obtaining an MRI scan. Based on the symptoms and the results of orthopedic examinations, the supraspinatus muscle is the most probable site of injury within the rotator cuff. This is because its anatomical position—in a confined space between the humerus and the acromion—makes it particularly vulnerable to damage.
Reference
Longo, U. G., Candela, V., Berton, A., Salvatore, G., Guarnieri, A., DeAngelis, J., & Denaro, V. (2019). Genetic basis of rotator cuff injury: A systematic review. BMC Medical Genetics, 20(1), 1-6. Web.