Fingers don't actually move without muscles; the misconception arises because the muscles responsible for finger movement are located primarily in the forearm and palm, not within the fingers themselves.
The Role of Tendons
The key to finger movement lies in the tendon unit. Muscles in the forearm and hand contract, and their force is transmitted via long tendons to the bones of the fingers. These tendons act like strings pulling on the bones, causing the fingers to bend and straighten. This explanation is supported by Dr. Amith Reddy P, Senior Consultant Orthopaedic Surgeon. As stated in the Indian Express article, “Muscles in the forearm end up as tendons in the hand. These muscles initiate the movements which, in turn, are transmitted to the tendons…”
- Forearm Muscles: The primary muscles responsible for finger movement are located in the forearm.
- Tendons: These strong, fibrous cords connect the forearm muscles to the bones in the fingers and hand.
- Bone Movement: When the forearm muscles contract, the tendons pull on the finger bones, resulting in flexion (bending) or extension (straightening).
The NHS website further clarifies that, "They move the bone when the muscle contracts. In the hand, tendons run along the front and back of the bones in the fingers and are attached to the muscles in..."
Precise Finger Control
The intricate movements of individual fingers are possible due to the complex arrangement of muscles, tendons, and bones. Each muscle often controls multiple tendons, allowing for a wide range of motion and the ability to move fingers independently. This is elaborated in the article "Muscular production of individuated finger movements", which details the complex interplay of extrinsic muscles responsible for finger movement.
In Summary
Fingers move because of the coordinated action of forearm and hand muscles and their connected tendons, not because of muscles residing within the fingers themselves. The tendons act as intermediaries, transmitting the force of muscle contractions to the bones of the fingers, enabling a wide range of movements.
