Course Instructor (P10)

0 313

Shoulder Injury

Biomechanics

The shoulder girdle is one of the most mobile anatomical structures in the body. The shoulder girdle moves in multiple directions, allowing the upper arm to assure an unlimited number of positions. The more positions it can assume will increase the number of possibilities for directional injury. It is the most frequently dislocated joint. Both over use and under use can lead to injury. Disuse will lead to adhesive capsulitis, while the rotator cuff injuries are increased with age (usually after 40). Impingement syndrome impacts those individuals who perform heavy duties, while women and adolescents can be more susceptible to instability, due to reduced upper body strength.

Anatomy

The sternum, the clavicle, the humerus and the scapula comprise the shoulder girdle. The four joints of each shoulder are the sternoclavicular joint, the acromioclavicular joint, the coracoclavicular joint and the glenohumeral joint.
The shallow glenoid fossa of the scapula accommodates the spherical head of the humerus adding to mobility and also structural weakness. The ligament support is comprised of the costoclavicular, acromioclavicular and coracoclavicular, acromion, sternoclavicular and glenohumeral ligaments.

Muscular control is vast. The biceps provide flexion and supination of the arm. The triceps extends the forearm and upper arm. The coracobrachialis adducts and assists in flexion and pronation of the arm. The rotator cuff provides rotational movements. The supraspinatus assists in abduction, the infraspinatus in external rotation; the teres minor also in external rotation and the subscapularis performs internal rotation and adduction. The rhomboids retract and rotate the scapula. The pectoralis major flexes, adducts, and internally rotates the arm. The pectoralis minor raises the ribs, draws the scapula forward, downward and inward causing shoulder depression The latissimus dorsi extends adducts posteriorly and rotates internally the arm and rotates the scapula downward. The levator scapula elevates the scapula, extends and allows lateral flexion of the neck and assist the downward rotation of the scapula. Serratus anterior rotates the scapula for abduction and flexion of the arm, while protracting the scapula. The teres major assists in extension, abduction and internal rotation of the arm. Finally, the trapezius retracts, rotates upward and elevates the scapula; it also rotates the scapula downward based on the fibers engaged.

Shoulder InjuryCommon Injuries

Violent rotation and pulling injuries are the most common shoulder injuries in golf.

  • Rotator Cuff – in golf, acute trauma is less common than chronic irritation due to repetition. Symptoms range from minimal pain with no weakness to severe pain and decreased range of motion and weakness. The latter suggests a tear of the rotator cuff. The diagnosis is based on stress testing the isolated muscles as described previously. Conservative care is almost always the first treatment approach. Unlike the greater weight bearing hip, the shoulder should not be drastically restricted by supports unless severe tears are present. Stabilization can lead to greater restriction and longer periods of rehabilitation. When inflammation is controlled, gradual progressive resistance muscle-toning exercises should be implemented. The exercises must be directed at preventing the existing range of motion limitation.
  • Glenohumeral Subluxation or Dislocation – 95% of these displacements are anterioward. Remember the glenohumeral joint is bound solely by soft tissue in the anterior structure. A coexisting rotator cuff injury should be suspected in any one over the age of 45. We will discuss two techniques for reduction of the subluxation/dislocation of the glenohumeral joint. The Simpson technique requires placing the patient prone on a table with the affected arm hanging free. Then the clinician would apply weight or gentle traction downward, expecting that muscular relaxation will permit the humerus head to slide back into place. The other technique is known as the Milch technique, this technique has the clinician abducting the arm overhead then externally rotating it. The head of the humerus is then pushed posteriorly back into the glenohumeral joint. In either case, a period of 2 to 3 weeks of immobilization is standard. The use of a daytime sling to prevent overstress is common, but will likely extend the rehabilitation period. This condition will also require analysis of neurovascular compromise.

The return to play may require a glenohumeral joint wrap as the patient returns gradually to competition. Using a 6 inch wide wrap, loop the affected arm with the bandage material, then wrap anteriorly across the chest, then under the arm and around the back, then finally over the affected shoulder and re-anchor it on the upper arm of the affected side.

You might also like

Leave A Reply

Your email address will not be published.