Shoulder Anatomy; Shoulder Sprain and Shoulder Strain
The shoulder is formed where the humerus, collar bone (clavicle), and scapula join. The rotator cuff holds the humerus in place. The muscles that form the shoulder are the supraspinatus, infraspinatus, tres minor, subscapularis, and deltoid. There are four rotator cuff tendons and two biceps tendons that make up the shoulder. These tendons connect the deep layers of the muscles to the scapula and humerus and provide support to the glenohumeral joint. The supraspinatus tendon is the most affected tendon due to overuse and trauma. The supraspinatus muscle is responsible for lifting the arms out to the side. An injury to this muscle can result in a rotator cuff tear or tears. Overuse can lead to shoulder (subacromial) impingement.
Shoulder Sprain (Acromioclavicular (AC) Joint Separation)
Shoulder separation occurs after falling directly onto the shoulder with the arm either tucked or restrained to the body. This type of injury usually occurs in male athletes who play contact sports such as football, rugby, wrestling, and mixed martial arts. This type of fall canalso cause shoulder dislocations, which occurs when the acromion loses contact with the acromioclavicular (AC)joint. Shoulder separations can also be caused my motor vehicle accidents.This particular injury causes tears in the ligaments surrounding the AC joint, which is located between the acromion process and collar bone. When someone falls with his or her arm outstretched, the distal clavicle and acromion process may be fractured. Injury to the AC joint can damage the cartilage within the joint, which can later cause arthritis in the AC joint. However, a joint sprain is more common than a fracture.
Presentation for a shoulder sprain: Patients who have been diagnosed with a shoulder sprain will complain of pain in their upper shoulder (the outer collarbone area) after a fall. Patients may complain of decreased mobility, swelling, and tenderness in the affected shoulder. Patients who have a high pain tolerance may find it difficult to lift weights (bench press) or perform upper body exercises (dips and shoulder press) due to shoulder and clavicle pain. Patients with a separated shoulder injury will also complain of increased pain at night while sleeping or when they try to roll or push off the affected shoulder.
Treatment plan: Rest, ice, NSAIDS, a shoulder sling to keep the shoulder immobile, and physical therapy are standard treatments for a shoulder injury. A follow up with a healthcare physician or direct visit to the ER is advisable for a full shoulder, clavicle, and scapular assessment for severe pain and decline in mobility. X-rays of the shoulder, clavicle, scapular, upper thoracic area, and cross body adduction may be performed to assess for fractures. To assess difficulty breathing and rib pain, an X-ray of the ribs (rib series) and chest will be performed. Depending on the severity of the pain and X-ray results, an MRI may be needed to evaluate the tissue for possible ligament and cartilage tears. Recovery time, physical therapy, and possible surgery will depend on the imaging results.
Shoulder Strain
A shoulder strain presents with increased muscle spasms and decreased mobility, the same presentation as shoulder sprain. Recovery time depends on the person and type of muscle injury.
References
Harvard Health Publishing. (2019). Shoulder Sprain. Retrieved from https://www.health.harvard.edu/a_to_z/shoulder-sprain-a-to-z
Mercy Health. (2019). Shoulder Strains or Sprains. Retrieved from https://www.mercy.com/health-care-services/orthopedics-sports-medicine-spine/specialties/shoulder-upper-arm/conditions/shoulder-sprain-strain