Biomechanics AA for Drinking Coffee

     Each morning I wake up and I drink a cup of coffee. My starting position for this is my elbow fully extended, shoulders adducted as my arms are hanging to my side and I am standing at the counter. In order to grab my coffee cup from the counter my major joint will be my elbow joint. My elbow joint will move in the sagittal plane and frontal axis to produce flexion of the elbow to not only grab the cup but also to bring it to my mouth. The digits of my hand will also be in flexion to grasp the cup and my wrist slightly extended. My end position will be my elbow in full flexion or WFL to be able to drink and the digits of the hand in flexion and wrist slightly extended. The osteokinematics of the elbow from extension to flexion is an open kinematic chain because the distal end of the chain, the forearm and hand, are the segments that are moving. In terms of arthokinematics, the moving segment, the ulna, is concave and will roll and glide in the same direction anteriorly on the convex surface of the humerus. The prime mover for elbow flexion is the brachialis which performs a concentric contraction.