An OT is preparing to use a goniometer to measure active flexion of a patients shoulder. The patient is positioned in supine with his knees flexed and his shoulder in no abduction, adduction or rotation. Where should the OT align the axis of the goniometer to accurately measure this motion?
A) Aligned with the midline of the humerus
B) At the head of the humerus
C) On the mid-axillary line
D) On the lateral epicondyle of the humerus