EFFICACY OF ADDING TRUNK INTEGRATED KINETIC CHAIN EXERCISES TO CONVENTIONAL EXERCISE THERAPY PROGRAM IN SUBACROMIAL IMPINGEMENT SYNDROME

Shoulder pain is the third most common musculoskeletal condition, affecting 67% of the general population . Shoulder impingement syndrome (SIS) is one of the most prevalent causes of shoulder pain, which is characterized by the compression of the rotator cuff and the subacromial bursa under subacromial space. Shoulder impingement syndrome is accounting for 44% to 65% of all shoulder complaints, with an estimated prevalence of 7% to 34%. In as many as 65% of SIS cases, shoulder pain is located in the anterolateral acromial region that may also spread to the lateral mid-humerus is the classic SIS symptom with a general decline in muscle strength.

New perspective for assessment and treatment of SIS is concentrating on movement-related mechanisms or biomechanical triggering factors. Exercises are effective at an early stage of SIS, which usually refers to stage I or early stage II according to Near's classification , such as training of the periscapular muscles (pectoralis minor, trapezius, serratus, and rhomboids) and strengthening of the rotator cuff (supraspinatus, infraspinatus, teres minor, and subscapularis), which acts as the shoulder joint stabilizers using concentric and eccentric exercises for the dynamic humeral centering effect and reduction of shoulder pain.). However, the best treatment strategy remains unknown If conservative treatment is failed operative treatment should be considered.

The scapula and glenohumeral joints are critical in allowing energy transfer from the trunk to lower limbs. According to Kibler et al, 1995, a 20% drop in kinetic energy transferred from the hip and trunk to the arm needs a 34% increase in shoulder rotational velocity to create the same amount of force to the hand. Deficiencies in the strength and mobility in these areas can have a negative impact on shoulder kinematics, increasing the risk of shoulder and elbow injury.

The defect at any link in the kinetic chain (Kc) will affect force transfer to subsequent segments and other components in the chain need to contribute more to compensate for the energy loss and this is explaining the risk factor for shoulder injury and pain. Recently, physical therapists typically recommend including lower extremity and trunk movements into shoulder rehabilitation protocols to maximize effective energy transfer throughout the entire KC. However, the importance of a KC approach over an isolated local shoulder treatment protocol during shoulder rehabilitation is not fully understood.

Previous studies investigated the efficacy of integrating the KC exercises into shoulder rehabilitation exercises and showed improvement of axio-scapular muscle recruitment, lower trapezius muscle ratios, and decrease the demands on the rotator cuff muscles.