Experience the Quality With Free MBLEx Exam Questions That Helps Candidates Pass

Kinesiology objectives on the MBLEx include prime movers, synergists, and joint actions. The middle deltoid and supraspinatus are primary abductors of the shoulder from 0–90°. Supraspinatus initiates abduction and contributes through the range while also stabilizing the humeral head in the glenoid. The middle deltoid provides the bulk of the torque as the arm rises. Scapular upward rotation (serratus anterior and upper/lower trapezius) complements humeral abduction via scapulohumeral rhythm but occurs at the scapulothoracic articulation. Option A lists adductors/internal rotators, not abductors. Option B’s sternal pectoralis major is a horizontal adductor/shoulder extender from flexed positions, not a primary abductor; the anterior deltoid assists flexion and horizontal adduction. Option D lists external rotators that stabilize but do not primarily abduct. Understanding prime movers guides targeted soft-tissue work—e.g., addressing tight adductors (latissimus, teres major, pectoralis major) that may limit abduction and supporting rotator cuff stability to maintain pain-free range. This knowledge informs assessment-driven treatment planning.