Ankle-foot Muscles Flashcards
Dorsal Foot Muscles:
Extensor Digitorum Brevis:
O: distal part of the superior & lateral surfaces of the calcaneus, lateral talocalcaneal ligament & apex of the inferior extensor retinaculum
I: by 4 tendons to the 1-4 digits, the most medial slip, also known as the extensor hallucis brevis, inserts into the dorsal surface of the base of the proximal phalanx of the great toe. The other 3 tendons join the lateral sides of the tendons of the extensor digitorum longus to the 2, 3 & 4 digits.
A: extends toes 01-4 at the metatarsophalangeal joints, assists in extension of interphalangeal joints of 2-4
N: deep peroneal (fibular) nerve (L4, L5, S1)
Muscle Testing:
Extensor Digitorum Longus & Brevis:
Patient: supine or sitting
Fixation: examiner stabilizes the foot in slight plantar flexion
Test: extension of all joints of the 2-5 digits
Pressure: against the dorsal surface of the toes
Dorsal Foot Muscles:
Extensor Hallucis Brevis:
O: distal part of the superior & lateral surfaces of the calcaneus, lateral talocalcaneal ligament & apex of inferior extensor retinaculum
I: dorsal surface of the base of the proximal phalanx of the great toe
A: Extends the metatarsophalangeal joint of the great toe
N: deep peroneal (fibular) nerve (L4, L5, S1)
Muscle Testing:
Extensor Hallucis Longus & Brevis:
Patient: supine or sitting
Fixation: examiner stabilizes the foot in slight plantar flexion
Test: extension of the metatarsophalangeal and interphalangeal joints of the big toe
Pressure: against the dorsal surface of the big toe
Plantar Foot Muscles - Layer 1:
Abductor Hallucis:
O: medial process of the tuberosity of the calcaneus, flexor retinaculum, plantar aponeurosis and adjacent intermuscular septum
I: medial side of the base of the proximal phalanx of the great toe, some fibers attached to the medial sesamoid bone and a tendinous slip may extend to the base of the proximal phalanx of the great toe
A: abducts and assists in flexion of the metatarsophalangeal (MTP) joint of the great toe and assists with adduction of the forefoot
N: medial plantar nerve via tibial nerve (L4, L5, S1)
Muscle Testing: Abductor Hallucis:
Patient: supine or sitting
Fixation: examiner grips the heel firmly
Test: abduction of the big toe from the axial line of the foot
Pressure: against the medial side of the first metatarsal and proximal phalanx
Plantar Foot Muscles - Layer 1:
Abductor Digiti Minimi:
O: calcaneal tuberosity, flexor retinaculum & plantar aponeurosis
I: base of proximal phalanx of little toe (lateral plantar side)
A: abduction of little toe
N: lateral plantar nerve via tibial nerve (S1, S2)
Plantar Foot Muscles - Layer 1:
Flexor Digitorum Brevis:
O: medial process of the tuberosity of the calcaneus, central part of the plantar aponeurosis & adjacent intermuscular septa
I: middle phalanx of the 2-5 digits
A: flexes the proximal interphalangeal joints and assists in flexion of the metatarsophalangeal joints of the 2-5 digits
N: medial plantar nerve via tibial nerve (L4, L5, S1)
Muscle Testing: Flexor Digitorum Brevis:
Patient: supine or sitting
Fixation: examiner stabilizes the proximal phalanges and maintains neutral foot
Test: flexion of the proximal interphalangeal joints of 2-5 digits
Pressure: against the plantar surface of the middle phalanges of 2-5 digits
Plantar Foot Muscles - Layer 2:
Quadratus Plantae:
O: medial head: medial surface of the calcaneus and medial border of the long plantar ligament
O: lateral head: lateral border of the plantar surface of the calcaneus and lateral border of the long plantar ligament
I: lateral margin and the dorsal plantar surfaces of the tendon of the flexor digitorum longus
A: modifies the line of pull of the flexor digitorum longus tendons, and assists in flexing the 2-5 digits
N: lateral plantar nerve via tibial nerve (S1, S2)
Plantar Foot Muscles - Layer 2:
Lumbricals (4):
O: 1: from the medial side of the 1st flexor digitorum longus tendon
O: 2: from the adjacent sides of the 1st & 2nd flexor digitorum longus tendons
O: 3: from the adjacent sides of the 2nd & 3rd flexor digitorum longus tendons
O: 4: from the adjacent sides of the 3rd & 4th flexor digitorum longus tendons
I: medial side of the proximal phalanx & dorsal expansion of the extensor digitorum longus tendon of 2-5 digits
A: flexes the metatarsophalangeal joints and assists in extending the interphalangeal joints of the 2-5 digits
N: 1: medial plantar nerve via tibial nerve (L4, L5, S1)
N: 2-4: lateral plantar nerve via tibial nerve (L4, L5, S1, S2)
Muscle Testing: Lumbricals:
Patient: supine or sitting
Fixation: examiner stabilizes the midtarsal region and maintains neutral foot
Test: flexion of the metatarsophalangeal joints of 2-5 digits
Pressure: against the plantar surface of the proximal phalanges of 2-5 digits
Plantar Muscles - Layer 3:
Flexor Hallucis Brevis:
O: medial part of the plantar surface of the cuboid bone, adjacent part of the lateral cuneiform bone, and from prolongation of the tendon of the tibialis posterior
I: medial & lateral sides of the base of the proximal phalanx of the great toe
A: flexes the metatarsophalangeal joint of the great toe
N: medial plantar nerve via tibial nerve (L4, L5, S1)
Muscle Testing: Flexor Hallucis Brevis:
Patient: supine or sitting
Fixation: examiner stabilizes the foot proximal to the metatarsophalangeal joint and and maintains neutral foot
Test: flexion of the metatarsophalangeal joints of the big toe
Pressure: against the plantar surface of the proximal phalanx of the big toe
Plantar Muscles - Layer 3:
Flexor Digiti Minimi:
O: base of 5th metatarsal & distal tendon of peroneus longus?
I: base of proximal phalanx of little toe or the 5th
A: flexion of little toe at the metatarsophalangeal joint
N: lateral plantar nerve via tibial nerve (S2, S3)
Plantar Muscles - Layer 3:
Adductor Hallucis:
O: oblique head: from the bases of the 2-4 metatarsal bones and the sheath of the tendon of the peroneus longus
O: transverse head: from the plantar metatarsophalangeal ligaments of the 3-5 digits and the deep transverse metatarsal ligament
I: lateral side of the base of the proximal phalanx of the great toe
A: adducts and assists in flexing the metatarsophalangeal joint of the great toe
N: lateral plantar nerve via tibial nerve (S1, S2)
Plantar Muscles - Layer 4:
Plantar Interossei (3):
O: bases and medial sides of the bodies of the 3-5 metatarsal bones
I: medial sides of the bases of the proximal phalanges of the same digit
A: adducts 3, 4 & 5 digits toward the axial line through the 2nd digit, assists in flexion of the metatarsophalangeal joints, and may assist in extension of the interphalangeal joints of the 3, 4 & 5 digits
N: lateral plantar nerve via tibial nerve (S1, S2)
Muscle Testing: Lumbricals:
Patient: supine or sitting
Fixation: examiner stabilizes the midtarsal region and maintains neutral foot
Test: flexion of the metatarsophalangeal joints of 2-5 digits
Pressure: against the plantar surface of the proximal phalanges of 2-5 digits
Plantar Muscles - Layer 4:
Dorsal Interossei (4):
O: each by 2 heads from the adjacent sides of the metatarsal bones
I: side of the proximal phalanx and capsule of the metatarsophalangeal joint
I: 1: to the medial side of the 2nd digit
I: 2-4: to the lateral sides of the 2-4 digits
A: abducts the 2-4 digits from the axial line through the 2nd digit, assists in flexion of the metatarsophalangeal joints, and may assist in extension of the interphalangeal joints of the 2-4 digits
N: lateral plantar nerve via tibial nerve (S1, S2)
Muscle Testing: Lumbricals
Patient: supine or sitting
Fixation: examiner stabilizes the midtarsal region and maintains neutral foot
Test: flexion of the metatarsophalangeal joints of 2-5 digits
Pressure: against the plantar surface of the proximal phalanges of 2-5 digits
