"The thumb is critically important due to its opposable nature, which allows it to touch and oppose the other fingers, enabling a wide range of precise and powerful movements. This unique ability is fundamental to grasping, pinching, and manipulating objects, from holding a pen to using tools, writing, crafting, and even throwing weapons. The thumb's saddle joint and two-phalange structure provide a greater range of motion than the other fingers, making it essential for dexterity.

Anatomically, the thumb is distinct: it has only two bones (phalanges) compared to the three in each finger, and its carpometacarpal joint allows for rotation, flexion, and opposition. This specialized structure supports over 40% of hand functions, and its loss results in a 40% impairment to the entire hand—equal to losing three other fingers."