Fingers are attached to the hand through a complex system of bones, ligaments, and tendons working together at the metacarpophalangeal (MCP) joints.
Here's a breakdown of how fingers are attached:
- Bones: Each finger (excluding the thumb) has three bones called phalanges: the proximal, middle, and distal phalanges. These bones articulate with each other and with the metacarpal bones of the hand at the MCP joint, forming the finger's skeletal structure.
- Ligaments: Ligaments are strong, fibrous tissues that connect bones to each other, providing stability to the joints. Key ligaments involved in finger attachment include:
- Collateral Ligaments: Located on the sides of each finger joint, these ligaments prevent excessive sideways movement and provide stability.
- Volar Plate: This is a thick, fibrocartilaginous structure on the palmar (palm) side of the finger joints. It connects the phalanges, preventing hyperextension and providing support. Volar plate ligaments specifically connect the first two finger bones (proximal and middle phalanges).
- Tendons: Tendons are tough, fibrous cords that connect muscles to bones, enabling movement. The tendons that control finger flexion (bending) and extension (straightening) pass through the wrist and hand, attaching to the phalanges. The flexor tendons are located on the palmar side, while the extensor tendons are on the dorsal (back) side.
- Joint Capsules: The MCP joint, like other synovial joints, is enclosed by a joint capsule. This capsule helps to stabilize the joint and contains synovial fluid, which lubricates the joint and reduces friction during movement.
In summary, fingers are not simply "glued" on. They are intricately connected to the hand through a network of bones, strong ligaments that prevent excessive movement, tendons that enable a wide range of motion, and supportive joint capsules. The Volar Plate Ligament specifically connects the first two bones in each finger.
