Leg Muscles Flashcards
Tibialis anterior IO Innervation
Origin:
* Upper 2/3 of lateral proximal tibia
* Lateral tibial condyle
* Interosseous membrane
Insertion:
* Medial and inferior surface of the medial cuneiform bone
* Adjacent surfaces on base of the 1st metatarsal bone
Innervation
Deep fibular nerve
Tibialis anterior Action
- Dorsiflexion of foot at ankle joint
- Inversion of foot at talar joints
- Dynamic support of medial longitudinal arch of foot
Extensor hallucis longus IO Innervation
Origin:
* Middle ½ of medial surface of fibula
* Adjacent surface of interosseous membrane
Insertion:
* Dorsal surface of base of the distal phalanx of 1st digit
Innervation
Deep fibular nerve
Extensor hallucis longus
- Dorsiflexion of foot at ankle joint
- Extension of 1st digit at MTP, IP joint
Extensor digitorum longus IO innervation
Origin:
* Proximal ½ of medial surface of fibula
* Lateral condyle of the tibia
* Interosseous membrane
Insertion:
* Bases of distal and middle phalanges of digits #2-5 via extensor expansions
Innervation
* Deep fibular nerve
Extensor digitorum longus Action
- Dorsiflexion of foot at ankle joint
- Extension of digits #2–5 at MTP, IP joints
Fibularis tertius IO Action Innervation
Origin:
* Medial surface of the distal fibula
Insertion:
* Dorsomedial surface of base of 5th metatarsal
Action
* Dorsiflexion of foot at ankle joint
* Eversion of foot at talar joints
Innervation
* Deep fibular nerve
Fibularis longus IO Innervation
Origin:
* Lateral surface of the proximal fibula
* Lateral tibial condyle
Insertion:
* Plantar aspect of lateral side of distal end of medial cuneiform bone and base of 1st metatarsal bone
Innervation
* Superficial fibular nerve
Fibularis longus Action
- Eversion of foot at talar joints
- Plantarflexion of foot at ankle joint
- Supports longitudinal and transverse arches of the foot
Fibularis brevis IO Action Innervation
Origin:
* Lower 2/3 of lateral surface of the fibula
* Intermuscular septum
Insertion:
* Tuberosity of the base of the 5th metatarsal
Action
* Eversion of foot at talar joints
* Plantarflexion of foot at ankle joint
Innervation
* Superficial fibular nerve
Gastrocnemius IO Action Innervation
Origin:
* Lateral head: Posterior surface of femur on upper posterolateral surface of lateral femoral condyle
- Medial head: Posterior surface of distal femur just superior to medial femoral condyle
Insertion:
* Posterior surface of the calcaneus via the calcaneal tendon
Action
* Plantarflexion of foot at ankle joint
* Flexion of leg at knee joint
Innervation
* Tibial nerve
Soleus IO Action Innervation
Origin:
* Soleal line and medial border of the tibia
* Posterior surface of the proximal fibula (head, neck, and proximal shaft)
* Fibrous arch between tibia and fibula
Insertion:
* Posterior surface of the calcaneus via the calcaneal tendon
Action:
* Plantarflexion of foot at ankle joint
Innervation:
* Tibial nerve
Plantaris IO Action Innervation
Origin:
* Lateral supracondylar line of femur
* Oblique popliteal ligament of knee
Insertion:
* Posterior surface of the calcaneus via the calcaneal tendon
Action
* Plantarflexion of foot at ankle joint
* Flexion of leg at knee joint
Innervation
* Tibial nerve
Tibialis posterior IO Innervation
Origin:
* Posterior surfaces of interosseous membrane
* Adjacent margin of the tibia and fibula
Insertion:
* Medial portion: Navicular tuberosity; Medial cuneiform (main insertion)
- Lateral portion: Intermediate and lateral cuneiforms; Bases of 2nd-4th metatarsal bones (and sometimes cuboid)
- Recurrent portion: Sustentaculum tali of the calcaneus
Innervation:
Tibial nerve
Tibialis posterior Action
- Plantarflexion of foot at ankle joint
- Inversion of foot at talar joints
- Supports medial longitudinal and transverse arches of the foot
Flexor digitorum longus IO Action Innervation
Origin:
* Middle 1/3 of the posterior surface of the tibia
Insertion:
* Plantar aspect of bases of the distal phalanges of digits #2-5
Action
* Flexion of digits #2 – 5 at IP, MTP joints
* Plantarflexion of foot at ankle joint
* Supports longitudinal arches of the foot
Flexion of DIP joints allows toes to grip the ground while walking
Innervation:
Tibial nerve
Flexor hallucis longus IO Action Innervation
Origin:
* Distal 2/3 of the posterior surface of the fibula
* Adjacent interosseous membrane
Insertion:
* Plantar surface of base of the distal phalanx of the 1st digit
Action
* Flexion of 1st digit at IP, MTP joint
* Plantarflexion of foot at ankle joint
* Supports longitudinal arches of the foot
Innervation
* Tibial nerve
Popliteus IO Action Innervation
Origin:
* Lateral condyle of the femur
Insertion:
* Posterior surface of the tibia above the soleal line
Action
* Flexion of the leg at knee joint
* Lateral rotation of femur on fixed tibia (“unlocks knee”)
* Medial rotation of tibia on unplanted limb
Innervation
* Tibial nerve
What muscle are innervated by Deep fibular nerve
Tibialis posterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius
What muscles are innervated by Superficial fibular nerve
Fibularis longus, brevis
What muscles are innervated by Tibial nerve
Gastrocnemius
Soleus
Flexor hallucis, digitorum longus
Plantaris
Popliteus
Difference between lateral and medial meniscus
*Lateral meniscus is smaller and shaped like the letter “O”4
*Lateral meniscus: not attached to collateral ligament and more mobile and less risk of injury
*Medial meniscus: more stationary and attaches to the collateral ligament
*Lateral meniscus attaches to the popliteus muscle
Where is the most common fracture site on tibia
*Junction of the inferior and middle two-thirds
*Tibial shaft at the site is the narrowest+close to the skin
*Most common location in the body for a compound fracture
Where is the common fibular nerve most susceptible to injury?
Neck of fibula
Common injury:
*Trauma or injury to the lateral aspect of the knee (laceration)
*Neck of fibula fracture (Bumper fracture)
*Use of tight plaster cast on the lower leg
*Crossing legs regularly
What muscles are innervated by common fibular nerve
Deep Fibular nerve
Anterior compartment:
Tibialis Anterior
Extensor Hallicus Longus
Extensor Digitorum Longus
Fibularis Tertius
Superficial Fibular nerve
Lateral Compartment:
Fibularis longus
Fibularis brevis
TEE F3
ACL and PCL IO, Uses
ACL
Origin:
tibial plateau between and anterior to the intercondylar eminences
Insertion:
Inner aspect of lateral femoral condyle
PCL
comprise of anterolateral bundle (larger) and posteromedial bundle (smaller)
Origin:
anterolateral aspect of the medial femoral condyle within the notch
Insertion:
posterior aspect of the tibial plateau
ACL resist:
*Anterior tibial translation
*IR loads
*valgus angulation
PCL resist:
*posterior tibial translation
*IR loads
*varus, valgus
LCL and MCL IO, Uses
Lateral Collateral Ligmanet:
Origin:
*Lateral epicondyle of the femur
Insertion:
*Fibula head
Function:
*resist varus stress
*ER of tibia
Medial Collateral Ligament:
Superficial
Origin:
*Medial epicondyle of the femur
Insertion:
*blends into semimembranosus tendon
*Posteromedial crest of the tibia
Deep(meniscofemoral)
Origin:
*femur just distal to the superficial medial collateral
Insertion:
*medial meniscus
Deep(meniscotibial)
Origin:
*medial meniscus
Insertion:
*distal edge of the articular cartilage of the medial tibial plateau
Function:
Resist valgus stress
*Resist
*rotational forces (IR+ER)
