The big toe is referred to as the first digit, and the pinky toe is the 5th digit.
Major Weight Bearing Areas
Distal aspect of the metatarsals.
Inferior portion of the calcaneus.
Arches of the Foot
Longitudinal Arch
Medial longitudinal arch.
Lateral longitudinal arch.
Runs from the calcaneus to the distal metatarsal heads.
Metatarsal Arch
Runs across the distal metatarsal heads.
Transverse Arch
Runs across the proximal metatarsal heads.
Energy-sparing spring theory: Central to understanding the foot’s mechanical function and evolution; the longitudinal arch saves elastic energy during running.
Clinical Applications - Flat Feet (Pes Planus)
Fallen arches result in ‘flat feet’ and is clinically termed Pes Planus.
Tibialis posterior dysfunction (trauma).
Calcaneonavicular ligament fails to support the head of the talus
Results in inferomedial displacement of the talar head.
Medial longitudinal arch flattens along with deviation of the forefoot.
Causes:
Weight gain
Prolonged standing
More common in older adults
Joints and Ligaments of the Ankle
Talocrural (Tibiotalar) Joint
Hinge joint allowing sagittal plane movement: dorsiflexion and plantarflexion.
Articulation between the medial malleolus of the tibia to the lateral malleolus of the fibula with the talus.
Lateral Ligaments (3)
Anterior talofibular ligament.
Calcaneofibular ligament.
Posterior talofibular ligament.
Medial (Deltoid) Ligaments (4)
Tibionavicular ligament.
Calcaneotibial (Tibiocalcaneal) ligament.
Posterior talotibial ligament.
Anterior talotibial ligament.
Note: Ligament names indicate the bones the ligament is connecting.
Tibiofibular Joint
Distal articulation between the tibia and fibula.
Held together by:
Interosseus ligament: between medial border of fibular shaft and lateral border of tibial shaft.
Anterior tibiofibular ligament.
Posterior tibiofibular ligament.
Clinical Application - Ankle Sprains
Inversion
Anterior Talofibular ligament is most commonly sprained.
Places stress on all lateral ligaments.
High Ankle Sprain (Syndesmosis Sprain)
Talus forces against the fibula causing widening of the talofibular joint.
Syndesmosis is an immovable joint in which two adjacent bones are linked by ligament(s).
Joints and Ligaments of the Foot
Subtalar Joint
Located between the calcaneus and talus.
Allows inversion and eversion.
Interphalangeal Joints
Metatarsophalangeal Joints
Intermetatarsal Joints
Tarsometatarsal Joints
Intertarsal Joints
Five groups of ligaments are associated with these joints:
Intertarsal ligaments.
Tarsometatarsal ligaments.
Intermetatarsal ligaments.
Metatarsophalangeal ligaments.
Interphalangeal ligaments.
Proximal Interphalangeal Joints (PIP)
Articulation of the proximal phalanges with the distal phalanx (1st digit) or middle phalanx (digits 2-5).
Distal Interphalangeal Joints (DIP)
Articulation of the middle phalanges (digits 2-5) with the distal phalanges (digits 2-5).
Clinical Applications Involving the Foot
Turf Toe
Hyperextension of the ligaments of the first metatarsophalangeal joint.
Plantar Fasciitis
Straining and inflammation of the plantar aponeurosis.
Symptoms:
Pain on the plantar surface of the heel and on the medial aspect of the foot.
Increased pain with passive extension of the great toe, as well as dorsiflexion and weight bearing.
Results from:
Running
High impact aerobics
Inappropriate footwear
Plantar fascia is a thick, tough band of tissue on the sole of the foot that supports the arch and helps with shock absorption during walking and running.
Movements of the Lower Leg, Ankle, and Foot
Ankle Movements
Dorsiflexion: toes up.
Plantarflexion: toes down.
Inversion: plantar aspect of the foot faces medial.
Eversion: plantar aspect of the foot faces lateral.
Foot Movements
Flexion and Extension
Tarsometatarsal, metatarsophalangeal, proximal interphalangeal, interphalangeal, and distal interphalangeal joints.
Abduction and Adduction
Metatarsophalangeal joints.
Muscles of the Lower Leg
12 muscles located in 4 compartments:
Anterior compartment
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Peroneus (fibularis) tertius
Lateral compartment
Peroneus longus
Peroneus brevis
Superficial posterior compartment
Gastrocnemius
Soleus
Plantaris
Deep posterior compartment
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus
Anterior Compartment
Tibialis Anterior
Origin: Lateral surface of tibia and interosseous membrane
Insertion: Inferior medial cuneiform and inferior base of 1st metatarsal
Action: Ankle dorsiflexion and inversion
Innervation: Deep fibular nerve
Extensor Digitorum Longus
Origin: Lateral tibial condyle and proximal ½ of fibula
Insertion: Dorsal side of middle and distal phalanges of toes 2-5
Action: Ankle dorsiflexion and extension of toes 2-5
Innervation: Deep fibular nerve
Extensor Hallucis Longus
Origin: Middle ½ of fibula and interosseous membrane
Insertion: Dorsal side of distal phalanx of digit 1
Action: Ankle dorsiflexion and extension of digit 1
Innervation: Deep fibular nerve
Peroneus (Fibularis) Tertius
Origin: Distal medial fibula
Insertion: Dorsal side of base of metatarsal 5
Action: Ankle dorsiflexion and eversion
Innervation: Deep fibular nerve
Considered in the anterior compartment despite its name (peroneus) meaning lateral
Clinical Application - Shin Splints
Inflammation of tendons of anterior and posterior tibialis muscles
Stress fractures: tibia and/or fibula
Inflammation of ligaments between tibia and fibula
Tears in the periosteum covering tibial shaft
Causes:
Footwear, longitudinal arch issues, surfaces, repetitive training
Lateral Compartment
Peroneus (Fibularis) Longus
Origin: Head of fibula and upper lateral fibula
Insertion: Plantar sides of medial cuneiform and base of metatarsal 1
Action: Ankle Eversion and some Plantarflexion
Innervation: Superficial fibular nerve
Peroneus means ‘lateral lower leg’
Peroneus (Fibularis) Brevis
Origin: Lower 2/3 of lateral fibula
Insertion: Lateral tubercle at base of metatarsal 5