Relationship of Scratch Test and Glenohumeral Internal Rotation and Horizontal Adduction Range of Motion

Limitation of shoulder range of motion (ROM) is associated with various shoulder injuries.1-3 Limited shoulder ROM is caused by tightness of muscles surrounding shoulder joint and glenohumeral (GH) joint capsule tightness.3-5 Especially, it has been reported limited GH internal rotation (IR) ROM due to tightness of posterior shoulder tissues leads to shoulder impingement and shoulder labrum lesion.1-3 In addition, tightness of posterior shoulder tissues induce anterior translation of humeral head during GH horizontal adduction (HA), that leads to abnormal arthrokinematics of GH joint.6 So, GH IR and HA passive ROM (PROM) is often measured to identify causes of shoulder injuries in clinical settings. Measures of GH IR PROM are generally performed in supine position with fixation of scapula for accurate measures.4,7-9 Similarly, GH HA PROM is measured while fixing scapular lateral boarder to limit unnecessary scapular movement.10,11 These methods facilitate measurement of shoulder ROM accurately; however, these methods could lead to difference in measured value depending on expertise of examiners. The scratch test is another way to measure combined shoulder IR ROM.12 During the scratch test, both hands are placed on upper and lower regions of the back, respectively, so combined shoulder IR, adduction, and extension in the lower arm side are measured.12 This maneuver has the advantage of facilitating quick and easy Relationship of Scratch Test and Glenohumeral Internal Rotation and Horizontal Adduction Range of Motion