MUSCLES OF THE LEG AND FOOT Flashcards
WK 7 (22 cards)
muscles of the leg
Anterior compartment
Anterior to malleolus
1. tibialis anterior (TA):
dorsi, inversion, M longit arch
2. extensor digitorum lognus (EDL):
dorsi, ext digits 2-5
3. extensor hallus longus (EHL):
dosri, ext digit 1
4. fibrialias (peroneous) teritus (FT/PT):
dorsi, eversion, L longit arch
muscles of the leg
Lateral compartment
Posterior to L mallelous
1. fibularis (peroneus) longus:
planatar, eversion, L longit arch
2. fibularis (peroneus) brevis:
planatar, eversion, L longit arch
muscles of the leg
Posterior compartment - superficial + deep
Posterior to malleloli
superficial:
1. gastrocnemuis (triceps surae):
plantar
2. soleus (triceps surae):
plantar
3. plantaris:
plantar
deep:
1. tibialis posterior (TP):
plantar, inversion, M + L long arch
2. flexor digitorum longus (FDL):
plantar, flex digits 2-5, M long arch
3. flexor hallus longus (FHL):
plantar, flex digit 1, M longit arch
4. popliteus:
unlock knee
Acessory features of the leg
- Retinacula
types, function
1. sup extensor retinaculum:
- hold tensons of ANT leg muscles
- horiz band to TC joint
2. inf extensor retinaculum:
- hold tendons of ANT leg muscles
- Y shaped
3. flexor retinaculum
- post to M malleolus
- hold tendons of TP, FDL, FHL
- creates a tarsal tunnnel - tendons, tib nerve, P tib vessels
4. sup + inf (peroneal) retinaculum:
- post to L malleolus
- hold down LAT leg muscles
Accessory features of the leg
- Synovial sheaths
structure, function
structure:
- dble layer syn membrane
- surr ea tendon
- pass under retinacula
fucntion:
- sliding + gliding of tendons
Accessory structures of the foot
- Plantar aponeurosis / plantar fascia
structure, function
structure:
- most superficial layer
- traingular shape
- attach to base of MT heads
function:
- bind to foot’s skin
- maintain foot arch
- attachment site for foot muscles
Accessory features of the Foot
- Dorsal digital expansion
structure:
- expansion of extensor digitorum longus tendon
function:
- simulataneous joint extension -> digital sweep
Normal toe flexion - Digital Sweep
what:
- longest muscular pathway for digit flexion
how:
- intrinsic muscles (interossei and lumbricals) insert into the DDE on the extensor side
process:
- they activate to cause ->
- flex @ MTP joint
- ext @ PIP and DIP joint therefore:
- ↓ Dysfunctional patterns during gait (e.g., toe clawing = excessive IP joint flexion)
Abnormal toe flexion - Toe clawing
1. Flexor Digitorum Longus (FDL):
Pulls the IP joints into flexion
→ Causes the toes to curl under
2. Extensor Digitorum Longus (EDL):
Pulls the MTP joints into hyperextension
→ Lifts the base of the toes too much
Intrinsic muscles (lumbricals, interossei) aren’t working properly to stabilize the toes
Movements of the foot
Inversion:
- iPADS
Eversion:
- eversion, abd, pronation
Muscles of the foot
intrinsic vs extrinsic
Intrinsic:
- O + I w in foot
Extrinsic:
- O outside foot (leg)
- I w in foot
Muscles of the foot
Dorsal
- extensor digitum brevis (EDB) - ext digits 2,3,4
- extensor hallucus brevis (EHB) - ext 1st digit
muscles of the foot
Plantar - Layer 1
one flexor bw 2 abd
1. abductor hallucis - abd 1st dig
2. flexor digitorium brevis (FDB) - flex digits 2-5
3. abductor digiti minimi (AbDM) - abd 5th digit
muscles of the foot
Plantar - Layer 2
two in layer 2
1. quadratus plantae (extrinsic):
- I into flexor digitorum longus tendon
- toe flexion
2. lumbricals:
- flex + add L 4 toes @ MTP joints
- ext 4 L toes @ IP joints
muscles of the foot
Plantar - Layer 3
one add bw 2 flexors
1. flexor hallucis brevis (FHB):
- 2 slips
- flex hallus @ MTP joints
2. Adductor hallucis:
- transverse and oblique head
- add hallucis
3. Flexor digitimini brevis (FDB) (no longus component)
- flex 5th digit
muscles of the foot
Plantar - Layer 4
1. Dorsal interossei x4:
- DAB (abd 2nd-4th digits)
2. Plantar Interossei x3:
- PAD (addd 3rd-5th digits)
*w reference to axis of foot
Arches of the Foot
types, helps to maintain
Types:
- medial arch:
⬆️ cruve, ⬆️ elastic
calcaneus, talus, navicular, all 3 cuneiforms, MT1,2,3
- lateral arch:
flatter, ⬆️ rigid
calcaneus, talus, cuboid, MT4 + 5
helps to maintain:
- bone congurency
- joint integrity
- tautness of ligaments
- muscle tension
Rigid vs Flexible
Step-off
- plantarfl ankle, extended MTP joints
- taut plantar aponeurosis
- ⬆️ M longitudinal foot arch
- talus head = superior
- ST joint = supinates
- mid-tarsal joint = locked
- foot = rigid -> ⬆️ Propulsion
Rigid vs Flexible
Heel Strike
- ST joint = pronate
- mid-tarsal joint = unlocks
- foot = flexible -> ⬆️ ability to pass forces thru foot
foot arches
Functions of Foot arches
rigid foot, flexible foot, in general
Rigid: Toe off
- ↑ force thru skeleton, ↑ propulsion
Flexible: Heel strike
- absorb forces sent thru skeleton
In General:
- absorb WB force / shock
- ↑ efficiency of WB (hindfoot/forefoot)
- ↑ eff propulsion (elastic recoil of arch when weight lifted off)
- adjust to uneven ground
foot arch
Maintenance of foot arches
1. Static Support (Passive)
- shape of the foot bones
2. Dynamic Support (Active)
a) Ligament Support – Plantar Aponeurosis
- Thick, triangle-shaped tissue under the foot
- During propulsion (toe-off):
toes extend → ↑ tension in the aponeurosis → ↑ tautness of long arch
b) Muscle Support
Bow Strings:
- Pull front + back of arch together
- ↑ stability of arch
Slings:
- Pull the top of the arch upward
- Keep the arch curved in the middle
Arches
Supports of the:
1. medial arch
2. lateral arch
3. transverse arch
1. Medial arch:
- plantar calcaneonavicular ligament
- I/O ligs w in M arch
- FHL
- FDL
- TP
- TA
- AbDH
2. Lateral arch:
- long planatar lig
- short plantar lig (CC lig)
- FL
- FB
- FT
- TP
- AbDM
- Longitudinal arch:
prox:
- MT bases
- cuboid
- prox end all 3 cuneiforms
distal:
- head of MT’s
