Interphalangeal joints
Commencing at the digits, the interphalangeal joints of each toe may be isolated quite simply. To isolate the distal interphalangeal joints of the lesser digits, stabilize the middle phalanx between the thumb and index finger of one hand, and with the other hand, grasp the distal phalanx and move it through a repetitive dorsiflexion/plantarflexion motion. To isolate the proximal interphalangeal joints of the lesser digits, repeat the process, this time stabilizing the proximal phalanx with one hand and moving the middle phalanx through a dorsiflexion/plantarflexion motion. Note that in the hallux, there are only two phalanges. Therefore, only one interphalangeal joint may be located. The interphalangeal joints are supported by medial and lateral collateral ligaments as well as plantar interphalangeal ligaments. The location of these ligaments and the shape of the articular surfaces allow only dorsiflexion and plantarflexion movements to occur at the interphalangeal joints.