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Department
of Podiatry
Joints
of the lower limb
Ankle
Joint
Anatomy
- mortise formed by tibia and fibula and its articulation with the
talus
Axis
- 8° from transverse plane (roughly aligns tips of malleoli),
20° from frontal plane
Motion
- primarily dorsiflexion / plantarflexion, with abduction / adduction
Major muscles acting at ankle
- tibialis anterior, extensors, triceps surae
Motion during gait
- early contact plantarflexion, then dorsiflexion as tibia moves over
foot during stance, then plantarflexion during propulsion
Click
here for a link to learn more about lateral ankle sprains
First
Ray
Anatomy
- functional unit consisting of 1st met. and medial cuneiform
- 1st met. and medial cuneiform with 2nd met.
- medial cuneiform with navicular, intermediate cuneiform and 2nd
met.
Axis
- 45° to frontal and sagittal planes
Motion
- dorsiflexion with inversion
- plantarflexion with eversion
Major muscles acting at first ray
- tibialis anterior and peroneus longus
Motion during gait
- dorsiflexes with pronation
- plantarflexion during propulsion to enable normal MPJ dorsiflexion
Lesser
Rays
Anatomy
- 2nd met. and intermediate cuneiform
- 3rd met. and lateral cuneiform
- 4th met. alone
Axes
- have not been studied
- probably lie in transverse plane, proximal to tarsometatarsal joints
Motion
- act in concert in sagittal plane, ie: dorsiflexion / plantarflexion
Major muscles acting at lesser rays
- interossei and lumbricals
Motion during gait
- locked into dorsiflexion during stance
- plantarflex during propulsion to enable normal lesser MPJ dorsiflexion
Fifth
Ray
Anatomy
- 5th met. alone
Axis
- 20° to transverse plane
- 35° to sagittal plane
Motion
- triplanar pronation and supination
- mainly inversion / eversion and plantarflexion / dorsiflexion
Major muscles acting at fifth ray
- peroneus tertius and brevis
Motion during gait
- has not been studied
Metatarsophalangeal
Joints
Anatomy
- met. head and base of proximal phalanx
- 1st MPJ also articulates with sesamoids
Axes
- transverse axis
- vertical axis
Motion
- plantarflexion / dorsiflexion
- adduction / abduction
Major muscles acting at MPJs
- 1st MPJ: adductor and abductor hallucis, FHB, FHL, EHB, EHL
- lesser MPJs: lumbricals, interossei, FDB, FDL, EDB, EDL
Motion during gait
- transverse plane motion is insignificant
- dorsiflexion required for normal propulsion
 References
Michaud
TC (1993) Foot orthoses and other forms of conservative foot care.
Williams and Wilkins, Baltimore, pp.9-14.
Root ML, Orien WP and Weed JH (1971) Clinical biomechanics: normal
and abnormal function of the foot. Clinical Biomechanics Corp,
Los Angeles, pp. 26-62.
Valmassy RL (1996) Clinical biomechanics of the lower extremity.
CV Mosby, St. Louis, Chapter 1.
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