Activity Analysis of Opening a Cabinet

        Everyday I open cabinets in my bathroom and in the kitchen. This activity is mainly accomplished by the elbow joint. The elbow starts in extension, the hand grasps the knob, and the elbow moves into flexion which opens the cabinet. The elbow is moving in the sagittal plane along the frontal axis. The osteokinematics of the elbow would be from extension to flexion in an open kinematic chain. The arthrokinematics of the elbow would include the convex surface of the humerus and concave surface of the trochlear notch on the ulna. During flexion the concave trochlear notch on the ulna rolls and glides anteriorly on the convex humerus. The agonist of this action is the biceps brachii as it is eccentrically contracting during elbow extension and concentrically contracting during elbow flexion.