Ankle Joint

Hinge joint = talus / tibia / fibula
Talus broader anteriorly wedged between malleoli during dorsiflexion , maximum stability of
the ankle is achieved during initial part of push off phase. Makes a Rigid lever arm that is
longer (pfl) for propulsion.


Transverse Tarsal (Midtarsal ) Joint

Composed of Talonavicular and Calcaneocuboid Joints
Also called Chopart's Joint. Synovial gliding joints. Medially = Talus and Navicular;
Laterally = Calcaneus and cuboid ; Two midtarsal axis (oblique and longitudinal)
Oblique axis allows combined saggital / transverse movement of the forefoot. ( ie. dfl comined with abd) Longitudinal axis allows inversion / aversion which permits the forefoot to adapt to the ground. A supinated subtalar joint decreases midtarsal joint motion.
A pronated subtalar joint does the opposite.


The First Ray

Composed of the first cuneiform and the first metatarsal. Peronrus Longus stabilizes the first ray against the vertical ground reaction force, before push off or propulsion phase of the gait cycle.
Axis located in transverse plane, 45 degrees to the saggital and frontal planes .
This produces inversion with dorsiflexion and eversion with plantarflexion.


-
Figures 26-Evaluation of range of motion of first ray

The normal first ray dorsiflexes and plantarflexes equally above and below the lesser rays (a). To evaluate for restricted range of motion, the thumb and index finger of one hand (right) stabilize the lesser metatarsal heads, while the thumb and index finger of the other hand (left) dorsiflex the first ray. If the first ray planterflexes (b1)
more than dorsiflexes (b2) (as indicated by the level of fingernails of the index fingers), a plantarflex first ray axists. If the first ray dorsiflexes (c2) more than plantarflexes (c1) a dorsiflexed first ray is presented.


The First Metatarsophalangeal Joint (MTPJ 1)

This is an articulation between the 1st metatarsal head and the base of the proximal phalanx of the hallux (big toe). The two sesamoid bones are included in this. Dorsiflexion of the 1st MTPJ is very important for normal locomotion. Minimum ROM is 65-75 degrees.
For the First 20-30 degrees the hallux rotates on the first MT head, after this the first metatarsal plantarflexes and glides in a planter direction. Any restriction (stopping) of this movement leads to joint subluxation and pain.