Interphalangeal joints of the foot

The primary function of the interphalangeal joints is to allow for the flexion and extension of the toes, which is essential for walking, running, and maintaining balance. During the push-off phase of walking, the toes need to flex downward to provide propulsion. Conversely, during the swing phase, the toes extend to clear the ground. This dynamic movement enables stability and mobility, facilitating an upright posture and the ability to navigate various terrains. The positioning and structure of these joints also contribute to the foot's overall biomechanics, keenly affecting gait and weight distribution across the foot during locomotion.

The interphalangeal joints are located in the foot at the connections between the toe bones. Each toe, except for the big toe, consists of three phalanges: the proximal phalanx, the middle phalanx, and the distal phalanx. The proximal interphalangeal joints are found between the proximal and middle phalanges, while the distal interphalangeal joints are positioned between the middle and distal phalanges. The joints of the big toe are slightly different, consisting of only two phalanges and hence having just one interphalangeal joint. This arrangement is crucial for the foot's mechanical function and agility.

• The foot has 14 phalanges, with the big toe typically featuring two and each of the other toes featuring three.
• Interphalangeal joints can sustain various injuries and ailments, such as arthritis, which can impair mobility.
• The stability of interphalangeal joints is maintained by ligaments and tendons, providing support during activity.
• The range of motion in these joints varies among individuals and can be influenced by footwear and activity level.