Final answer:
Angular movements like bending the arm at the elbow involve muscles, with the biceps brachii and triceps brachii being the primary muscles for flexion and extension at this joint.
Step-by-step explanation:
Angular movements, such as bending the arm at the elbow, require the use of muscles. When you bend your arm, muscles such as the biceps brachii are contracting to decrease the angle at the elbow joint, a process known as flexion. Conversely, when you straighten your arm, the triceps brachii muscle extends the forearm. Ligaments, such as the ulnar and radial collateral ligaments, provide support to joints but do not facilitate movement. Tendons attach muscle to bone and do transmit the force created by muscles to bones to create movement, but they are not the primary movers. Cartilage, on the other hand, reduces friction and absorbs shock within the joint and does not contribute directly to movement.