Reflection 1 - Movements

Each day I wake up in the morning and straighten my hair for class. When I reach for the straightener, my elbow is in an extended position and my wrist and should are in a flexed position. After I have picked up my straightener, my elbow moved into a flexed position. My wrist and shoulder remain in a flexed position. Extension of my elbow occurs in the sagittal plane about a frontal axis. Flexion of my shoulder and wrist also occur in the sagittal plane about the frontal axis. The osteokinematics of the shoulder, elbow, and wrist are in a open kinematic chain. In terms of arthrokinematics, the moving ulna is the concave segment which glides in the same direction on the humerus. The prime mover for elbow extension is the triceps brachii, which performs an eccentric contraction. The prime movers for when the elbow flexes are the biceps brachii, brachialis, and brachioradialis, which perform concentric contractions. The prime mover for shoulder flexion is the anterior deltoid, which performs a concentric contraction.