Our fingers move because of a complex interaction between muscles, tendons, and bones. Muscles in the forearm, called extrinsic muscles, are responsible for initiating most finger movements. These muscles connect to the bones of the fingers through long tendons that run through the hand. When a muscle contracts, the tendon pulls on the bone, causing the finger to bend or straighten.
The intrinsic muscles, located within the hand itself, provide fine-tuning control for more precise movements. They are responsible for tasks like gripping, pinching, and opposition of the thumb.
Here's a simplified breakdown:
- Muscles contract: When you want to move your finger, the muscles in your forearm contract.
- Tendons pull: The contracted muscles pull on the tendons that are attached to your finger bones.
- Bones move: The tension in the tendons causes the finger bones to move, resulting in the desired movement.
The hand can grasp and move objects in two different ways: with a power grip or precision grip. The type of grip used depends on the object's size, shape, weight, and ease of manipulation.
