10) Plantar Foot (Part II) Flashcards
The 2nd layer of the plantar aspect of the foot contains
5 muscles (4 lumbircals and quadratus plantae) 2 tendons (FDL and FHL) *all muscles attach to FDL*
Characteristics of Quadratus plantae (Flexor accessorius)
Deep to Flexor digitorum brevis 2 heads (origins)
Origins of Medial and Lateral head of Quadratus plantae
Medial surface of calcaneus (Medial)
Trigonum plantare and Inferior calcaneus distal to lateral tubercle
Origins of Quadratus plantae separated by
Long plantar ligament
Insertion of Quadratus plantae
Heads unit to insert onto FDL tendon
Blood supply to Quadratus plantae
Medial and Lateral plantar arteries
Innervation to Quadratus plantae
Lateral plantar nerve
Function of Quadratus plantae
Redirecting line of pull of FDL
Assisting in flexion of phalanges
Characteristics of lumbricals (Lumbricale muscles)
1 - Unipennate
2, 3, 4 - Bipennate
Origin of 1st lumbrical
Medial side of `1st tendon of FDL (which goes to 2nd digit)
Origin of 2nd-4th lumbrical
Adjacent tendons
For 3rd lumbrical (medial side of 3rd and lateral side of 2nd)
Path of tendons of lumbricals
Distally, they pass plantar to the transverse metatarsal ligament
Inesrtion of lumbricals
Medial aspect of extensor wing of extensor expansion at base of proximal phalanx of digits 2-5
(1st lumbrical to 2nd digit, etc.)
Blood supply to lumbricals
Respective plantar metatarsal arteries
Innervation to lumbricals
1st lumbrical (Medial plantar nerve) 2nd-4th lumbrical (Deep branch of lateral plantar nerve)
Function of lumbricals
Flexion of MTP joints
Extension of PIP and DIP joints
Origin of Flexor hallucis brevis (2 heads)
Lateral (Plantar surface of cuboid and lateral cuneiform)
Medial (Tibialis posterior tendon)
Insertion of Flexor hallucis brevis
Medial and lateral base of proximal phalanx
Invest respective hallux sesamoids before phalangeal insertion
Halux sesamoids and FHB
Sesamoids increase the mechanical advantage of FHB
Act as weightbearing structures and decrease friction
Blood supply to Flexor hallucis brevis
1st plantar metatarsal artery
Innervation to Flexor hallucis brevis
Medial plantar nerve
Function of flexor hallucis brevis
Plantarflexion of hallux MTP joint
Origin of Flexor digiti minimi brevis
Base of 5th metatarsal
Tendon sheath of fibularis longus
Insertion of Flexor digiti minimi brevis
Plantar/lateral aspect of base of proximal phalanx of 5th toe
Blood supply to Flexor digiti minimi brevis
Lateral plantar artery
Innervation to Flexor digiti minimi brevis
Superficial branch of Lateral plantar nerve
Function of Flexor digiti minimi brevis
Plantarflexion of 5th digit at MTP joint
Origin of Adductor hallucis heads
Transverse (Fibrous capsule, Plantar plates of digits 3-5, Deep transverse metatarsal ligament)
Oblique (Plantar aspect of metatarsal bases 2-4, Fibulari longus tendon sheath)
Insertion of Adductor hallucis
Lateral sesamoid
Lateral aspect of proximal phalanx base of 1st digit
Blood supply to Adductor hallucis
Plantar metatarsal arteries
Innervation to Adductor hallucis
Deep branch of lateral plantar nerve
Function of Adductor hallucis
Adduction of hallux
Origin of Opponens digiti minimi
Base of 5th metatarsal
Long plantar ligament
FDMB
Insertion of Opponens digiti minimi
Lateral shaft of 5th metatarsal and surrounding fascia
Function of Opponens digiti minimi
Abduction and flexion of 5th toe
The 4th layer of the Plantar aspect of the foot has how many muscle groups?
2
Dorsal and Plantar Interossei
Dorsal/plantar interossei are located
Within metatarsal spaces (no association with hallux)
Path of tendons of dorsal/plantar interossei
Dorsal to deep transverse metatarsal ligament
of interossei
3 Plantar
4 Dorsal
PAD DAB
Plantar ADducts
Dorsal ABducts
What tendons in 4th layer?
Tibialis posterior
Fibularis longus
Characteristics of Plantar Interossei muscles
3 in number
Assoc. with digits 3, 4, 5
Unipennate
Origin of Plantar interosseus muscles
Base and medial aspect of shafts of metatarsals 3, 4, 5
Inserion of Plantar interosseus muscles
Medial aspect of base of proximal phalanx
Extensor expansion of the same digit
How is the origin/ insertion of Plantar interossei organized?
1st plantar interossei originates from 3rd met Inserts onto proximal phalanx/extensor expansion of 3rd digit 2nd PI (4th digit) 3rd PI (5th digit)
Blood supply to Plantar interossei muscles
Plantar metatarsal arteries 2-4
Innervation to Plantar interossei muscles
Lateral plantar nerve Superficial branch (3rd PI) Deep branch (1st and 2nd PI)
Function of Plantar interossei muscles
Adduction of digits 3-5 toward foot midline
Plantarflexion 3-5 MTP joint
Ext (dorsiflexion) of IP joints 3-5
Characteristics of Dorsal interossei muscles
4 in number Assoc. with digits 2-4 Digit 2***** has two dorsal interossei inserting BIpennate Located within intermetatarsal space
Origin of Dorsal interossei muscles
Adjacent metatarsal shafts
How is the origin of Dorsal interossei organized?
1st DI originates at lateral aspect of 1st met shaft and medial aspect of 2nd
Insertion of Dorsal interossei
1st DI (medial aspect of base of proximal phalanx and extensor expansion of 2nd digit) 2nd-4th DI (lateral aspect of base of proximal phalanx and extensor expansion of corresponding digit)
How is the insertion of Dorsal interossei organized?
2nd DI inserts on lateral base of proximal phalanx and extensor expansion of digit 2
3rd - Digit 3
Etc.
Blood supply to Dorsal interossei muscles
Corresponding dorsal metatarsal artery
Innervation to Dorsal interossei muscles
Lateral plantar nerve
Deep branch of lateral plantar nerve innervates
1st, 2nd, 3rd DI
Superficial branch of lateral plantar nerve innervates
4th DI
1st and 2nd DI also receive innervation from
Deep fibular nerve
Function of Dorsal interossei muscles
Abduction of digits 2-4
Plantarflexion of MTP joints
Ext (dorsiflexion) of IP joints
IM spaces, DI, and PI
Write out on paper (too much for here)
What keeps the tendons anchored to the bone?
Fibrous flexor sheath
FHL, FDB, and FDL are surrounded by
Synovial sheath (to reduce friction)
Vincula brevia and Vincula longa???
idk
The Extensor Expansion is
A tendinofibroaponeurotic structure that is involved in the extensor function of the digits
The extensor expansion is formed by
Extrinsic muscles (EDL and EHL) Intrinsic muscles (EDB, lumbricals, interossei)
Other than providing the extensor function to digits, the Extensor expansion also
Stabilizes ligaments via
Sling and wing
Triangular lamina
The extensor sling is located
proximally
Fibers of the extensor sling
Transversely oriented
Pass around MTP joint
The extensor sling attaches
Plantar plate and deep transverse metatarsal ligament
What inserts into the extensor sling?
Interossei muscles
The extensor sling anchors
EDL (allows it to extend all digits)
The extensor wing makes up
The distal portion of the extensor expansion
Fibers of the extensor wing
Oriented obliquely (triangular shaped) Located at proximal phalanx
What inserts into the medial side of the extensor wing?
Lumbricals
EDL tendon characteristics
Form central axis of extensor expansion
Stabilized by sling at MTP joint
EDL tendons divide
Into 3 slips at MTP joint (some say proximal phalanx)
What are the slips of the EDL tendon?
Medial, Lateral, and Central
Path of Medial and Lateral slips of the EDL tendons
Extend over dorsum of middle phalanx
Insert into base of distal phalanx as a terminal tendon
Path of Middle slip of the EDL tendons
Inserts into base of middle phalanx
Location of Triangular lamina
Between lateral slips of EDL
Function of triangular lamina
Not known
The triangular lamina is believed to anchor
Medial and lateral slips (keeps them from sliding plantarward)
EDB tendons can take two paths:
Joining the EDL tendon
OR
Forming lateral slip instead
The EHB attaches
To the base of the proximal phalanx
Lumbrical tendons path
Tendons pass plantar to deep transverse metatarsal ligament
Inserts into wing
May form medial slip
Insertion of the lumbrical tendon into the wing allows for
Flexion of the MTP joint
Extension of the IP joints
Interosseus tendons path
Tendons pass dorsal to deep transverse metatarsal ligament
Insert into base of proximal phalanx at tubercle
Inserts into extensor apparatus at the sling (semi-disputed)