Ankle, subtalar, and foot anatomy and function - Lab 6

Each lab group needs:
  1. Palpable structures

    Locate on yourself and on a partner the palpable structures listed in your text (Smith, Weiss, & Lehmkuhl, 1996, pp. 333-336).

    • medial and lateral malleoli
    • sustentaculum tali (on the calcaneus)
    • navicular tuberosity
    • anterior portion of talus
    • deltoid ligament
    • first cuneiform
    • first metatarsophalangeal (MTP) joint line
    • calcaneus
    • cuboid
    • first through fifth metatarsals
    • lateral collateral ligaments
      • anterior talo-fibular
      • posterior talo-fibular
      • calcaneo-fibular

  2. Extrinsic muscles of the foot

    Extrinsic foot muscles are so named because each has an attachment that is located outside the foot. Extrinsic foot muscles are multi-articular; they cross and, therefore, produce movement at more than one articulation or joint. Each extrinsic foot muscle either dorsiflexes or plantar flexes the ankle (talocrural) joint, and either pronates or supinates the subtalar joint.

    Use skin pencils to draw lines of application, local to the ankle and subtalar joint, for each extrinsic foot muscle.

    Based on the relationship of the relevant line of application, local to the axes of the ankle and subtalar joints (Smith, Weiss, & Lehmkuhl, 1996, Fig. 10-2, p. 337), predict each muscle's action at either joint.

    Extrinsic muscles of the foot

    Muscle's action at ankle (talocrural) joint (either DF or PF)
    Muscle's action at subtalar joint either pronation or supination

    1. tibialis posterior
    2. flexor digitorum longus
    3. flexor hallucis longus
    4. tibialis anterior
    5. extensor digitorum longus
    6. extensor hallucis longus
    7. peroneus longus and brevis
    8. gastrocnemeus and soleus

  3. To produce certain movements, extrinsic muscles must act in synergies. List a pair of muscles that, acting in synergy, produce each specific movement.

    Ankle dorsiflexion without subtalar pronation or supination

    ____________________ and _______________________

    Ankle plantar flexion without subtalar pronation or supination:

    ____________________ and ________________________

    Subtalar pronation without ankle dorsiflexion or plantar flexion

    _____________________ and ________________________

    Subtalar supination without ankle dorsiflexion or plantar flexion

    _____________________ and ________________________

Last updated 9-19-01 Dave Thompson PT
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