What does the arm do?

1. Flexion and extension:

The arm allows for flexion (bending) and extension (straightening) movements at the elbow joint, which is made up of the humerus (upper arm bone) and the ulna and radius (forearm bones). This enables us to bring our hand towards the shoulder or straighten it in various positions.

2. Rotation:

The arm allows for rotation, both inward and outward, at the shoulder joint where the humerus meets the scapula (shoulder blade). Inward rotation (turning the palm face down) and outward rotation (turning the palm face up) are essential movements for many daily activities.

3. Abduction and adduction:

Abduction is the movement of the arm away from the body, while adduction is the movement towards the body. These movements are made possible by the muscles surrounding the shoulder joint and are important for reaching, pointing, and hugging, among other tasks.

4. Raising and lowering:

The arm can be raised (upward movement) or lowered (downward movement) at the shoulder joint. These actions involve the coordinated work of several muscles, enabling us to lift objects overhead or reach down to the ground.

5. Fine motor control:

The arm plays a crucial role in fine motor control, which involves the precise movements of the hand and fingers. This is enabled by the numerous small muscles and complex interactions between the bones, joints, muscles, and nerves in the arm and hand.

6. Support and stability:

The arm provides support and stability for the hands, allowing us to perform tasks such as holding objects, pushing or pulling, and maintaining balance.

The arm's range of motion and flexibility allow us to perform countless movements and activities with precision and strength, making it an integral part of our daily interactions with the environment and our ability to carry out various tasks.