Foot and Ankle Anatomy

Resources: Getbodysmart.com http://www.getbodysmart.com/

Bones The foot is made up of 26 bones The lower leg is comprised of 2 bones Forming the foot and ankle mortise of 28 bones

Bones of the foot

Muscles There are 19 muscles and tendons (tendon attaches muscle to bone)  muscles acting on the foot can be classified into extrinsic muscles, those originating on the anterior or posterior aspect of the lower leg, and intrinsic muscles, originating on the dorsal (top) or plantar (base) aspects of the foot.

Anterior compartment Muscle Origin Insertion Action tibialis anterior shaft of tibia and interosseous membrane medial cuneiform & base of first metatarsal extends the foot; inverts foot; supports medial longitudinal arch extensor digitorum shaft of fibula and interosseous membrane extensor expansion of lateral four toes extends toes; dorsiflexes (extends) foot extensor hallucis longus shaft of fibula & interosseous membrane base of distal phalanx of big toe extends big toe; dorsiflexes (extends) foot; inverts foot at subtalar and transverse tarsal joints

base of 1st MT & medial cuneiform Lateral Compartment peroneus longus shaft of fibula base of 1st MT & medial cuneiform plantar flexes foot; everts foot at subtalar & transverse tarsal joints; supports lateral longitudinal and transverse arches of foot peroneus brevis base of 5th metatarsal bone plantar flexes foot; everts foot at subtalar & transverse tarsal joints; supports lateral longitudinal arch

Posterior Compartment gastrocnemius medial and lateral condyles of femur by way of Achilles tendon to calcaneum plantar flexes foot; flexes leg plantaris lateral supracondylar ridge of femur calcaneum soleus shafts of tibia and fibula by way of achilles tendon into calcaneum with gastrocnemius & plantaris is powerful plantar flexor of foot; provides main propulsive force in walking & running popliteus lateral condyle of femur shaft of tibia flexes leg; unlocks full extension of knee by laterally rotating femur on tibia flexor digitorum longus distal phalanges of lateral four toes flexes distal phalanges of lateral four toes; plantar flexes foot; supports medial and lateral longitudinal arches of foot flexor hallucis longus shaft of fibula base of distal phalanx of big toe flexes distal phalanx of big toe; plantar flexes foot; supports medial longitudinal arch

Dorsum of foot extensor digitorum brevis calcaneum by four tendons into the proximal phalanx of big toe and long extensor tendons to 2nd, 3rd and 4th toes extends toes

1st layer of sole abductor hallucis medial tubercle of calcaneum; flexor retinaculum medial side, base of proximal phalanx of big toe flexes, abducts big toe; supports medial arch flexor digitorum brevis medial tubercle of calcaneum middle phalanx of four lateral toes flexes lateral four toes; supports medial & lateral longitudinal arches abductor digiti minimi medial & lateral tubercles of calcaneum lateral side base of proximal phalanx 5th toe flexes, abducts 5th toe; supports lateral longitudinal arch

Muscles of Lower leg

Muscles of foot

Ligaments The lateral and medial ligaments of the ankle support and strengthen the joint. The deltoid ligament is stronger than the lateral ligaments. The strength of the deltoid prevents most eversions.

Primary Primary ligaments of ankle include: medial lateral Deltoid ligament - This strong ligament attaches to the medial malleolus. It has four parts named for the bones that they attach to: the tibionavicular, the tibiocalcaneal, the anterior tibiotalar, and the posterior tibiotalar Calcaneonavicular ligament (Spring Ligament)  lateral Syndesmosis (includes AITFL, PITFL, TTFL, IOL, ITL) Anterior talofibular ligament (ATFL) Posterior talofibular ligament (PTFL) Calcaneal fibular ligament (CFL) Lateral talocalcaneal ligament (LTCL)

If you’ve ever sprained an ankle, you injured one or more of the ligaments that hold the joint together. The lateral ligaments are damaged more often than the stronger medial ligament.

Lateral View

Medial View

Simplified View (lateral)

Arches of the foot

Medial/Lateral

Medial/Lateral Medial arch is higher than the lateral longitudinal arch. It is made up by the calcaneus, the talus, the navicular, the three cuneiforms, and the first, second, and third metatarsals The lateral arch is composed of the calcaneus, the cuboid, and the fourth and fifth metatarsals

On a person

Problem with arches

Lower Leg

Putting it all together

In Class.. Begin Body Diagram… Draw foot bones Draw lateral and medial ligaments

Homework Color worksheet pages