Muscles of the Lower Limb Flashcards
What is the proximal attachment of Gluteus maximus?
Ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; sacrotuberous ligament
This muscle is the largest in the gluteal region and plays a crucial role in hip extension.
What is the distal attachment of Gluteus maximus?
Most fibers end in iliotibial tract, which inserts into lateral condyle of tibia; some fibers insert on gluteal tuberosity
The iliotibial tract is important for stabilizing the knee during activities.
Which nerve innervates Gluteus maximus?
Inferior gluteal nerve (L5, S1, S2)
This nerve is essential for the motor function of the muscle.
What is the main action of Gluteus maximus?
Extends hip joint (especially from flexed position) and assists in lateral rotation; fixes hip joint and assists in rising from sitting position
Its function is critical for movements like standing up and climbing.
What is the proximal attachment of Gluteus medius?
External surface of ilium between anterior and posterior gluteal lines
This muscle is located on the side of the hip.
What is the distal attachment of Gluteus medius?
Lateral surface of greater trochanter of femur
This position allows it to effectively influence hip movement.
Which nerve innervates Gluteus medius?
Superior gluteal nerve (L5, S1)
This nerve is responsible for the muscle’s function in hip movements.
What is the main action of Gluteus medius?
Abduct and medially rotate hip joint; keep pelvis level when ipsilateral limb is weight bearing and advance opposite (unsupported) side during its swing phase
This action is vital for walking and maintaining balance.
What is the proximal attachment of Gluteus minimus?
External surface of ilium between anterior and inferior gluteal lines
This muscle lies beneath the Gluteus medius.
What is the distal attachment of Gluteus minimus?
Anterior surface of greater trochanter of femur
It assists in the stabilization of the hip.
What is the proximal attachment of Tensor fasciae latae?
Anterior superior iliac spine; anterior part of iliac crest
This muscle contributes to the stability of the pelvis.
What is the distal attachment of Tensor fasciae latae?
Iliotibial tract, which attaches to lateral condyle of tibia
This connection aids in knee stability during movement.
What is the proximal attachment of Piriformis?
Anterior surface of sacrum; sacrotuberous ligament
It is a key muscle for hip rotation.
What is the distal attachment of Piriformis?
Superior border of greater trochanter of femur
This muscle plays a role in lateral rotation of the hip.
Which nerves innervate Piriformis?
Branches of anterior rami of S1 and S2
These branches are important for the muscle’s function.
What is the main action of Piriformis?
Laterally rotate extended hip joint and abduct hip joint when flexed; stabilize hip joint
Its role is important during various hip movements.
What is the proximal attachment of Obturator internus?
Pelvic surface of obturator membrane and surrounding bones
This muscle is involved in the rotation of the hip.
What is the distal attachment of Obturator internus?
Medial surface of greater trochanter (trochanteric fossa) of femur
This attachment allows it to exert its rotational force.
Which nerve innervates Obturator internus?
Nerve to obturator internus (L5, S1)
This nerve is crucial for its motor function.
What is the proximal attachment of Superior and Inferior gemelli?
Superior: ischial spine; Inferior: ischial tuberosity
These muscles assist in hip rotation.
What is the distal attachment of Superior and Inferior gemelli?
Medial surface of greater trochanter (trochanteric fossa) of femur
Their attachment allows them to assist in the action of Obturator internus.
Which nerves innervate Superior and Inferior gemelli?
Superior gemellus: same nerve supply as obturator internus; Inferior gemellus: same nerve supply as quadratus femoris
This relationship highlights their functional connection.
What is the proximal attachment of Quadratus femoris?
Lateral border of ischial tuberosity
This muscle plays a role in hip stabilization.
What is the distal attachment of Quadratus femoris?
Quadrate tubercle on intertrochanteric crest of femur and area inferior to it
This position enhances its mechanical advantage in hip rotation.
Which nerve innervates Quadratus femoris?
Nerve to quadratus femoris (L5, S1)
This nerve is essential for the muscle’s function.
What is the main action of Quadratus femoris?
Laterally rotates hip joint; stabilizes hip joint
Its action is crucial during activities requiring hip movement.
What is the proximal attachment of the Semitendinosus muscle?
Ischial tuberosity
The ischial tuberosity is a bony prominence on the inferior part of the pelvis.
What is the distal attachment of the Semitendinosus muscle?
Superior part of medial surface of tibia (as part of pes anserinus)
Pes anserinus is a conjoined tendon of three muscles on the medial side of the knee.
Which nerve innervates the Semitendinosus muscle?
Tibial division of sciatic nerve (L5, S1, S2)
This nerve supplies the muscles in the posterior compartment of the thigh.
What is the main action of the Semitendinosus muscle?
Extend hip joint; flex knee joint and medially rotate it when flexed
When both hip and knee joints are flexed, Semitendinosus can assist in extending the trunk at the hip joint.
What is the proximal attachment of the Semimembranosus muscle?
Posterior part of medial condyle of tibia
The semimembranosus muscle has a reflected attachment forming the oblique popliteal ligament.
What is the distal attachment of the Semimembranosus muscle?
Forms oblique popliteal ligament (to lateral femoral condyle)
This ligament provides stability to the knee joint.
What is the main action of the Semimembranosus muscle?
Extend hip joint; flex knee joint and medially rotate it when flexed
Similar to Semitendinosus, it can also extend the trunk when both joints are flexed.
What are the proximal attachments of the Biceps femoris muscle?
Long head: ischial tuberosity; Short head: linea aspera and lateral supracondylar line of femur
The long head originates from the ischial tuberosity, while the short head originates from the femur.
What is the distal attachment of the Biceps femoris muscle?
Lateral side of head of fibula
The tendon of the biceps femoris is split at this site by the fibular collateral ligament of the knee.
Which nerves innervate the Biceps femoris muscle?
Long head: tibial division of sciatic nerve (L5, S1, S2); Short head: common fibular division of sciatic nerve (L5, S1, S2)
The long head is innervated by the tibial nerve, while the short head is innervated by the common fibular nerve.
What is the main action of the Biceps femoris muscle?
Flexes knee joint and laterally rotates it when flexed; long head extends hip joint
This muscle plays a crucial role in activities such as walking and rising from a seated position.
What is the proximal attachment of Tibialis anterior?
Lateral condyle and superior half of lateral surface of tibia and interosseous membrane
Tibialis anterior is crucial for ankle dorsiflexion and subtalar joint inversion.
What is the distal attachment of Tibialis anterior?
Medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
This attachment is essential for the muscle’s action in foot movement.
What is the innervation of Tibialis anterior?
Deep fibular nerve (L4, L5)
The deep fibular nerve is responsible for the motor function of this muscle.
What is the main action of Tibialis anterior?
Dorsiflexes ankle joint and inverts subtalar joint
This muscle plays a key role in walking and balance.
What is the proximal attachment of Extensor digitorum longus?
Lateral condyle of tibia and superior three quarters of medial surface of fibula and interosseous membrane
This attachment allows the muscle to extend the toes effectively.
What is the distal attachment of Extensor digitorum longus?
Middle and distal phalanges of lateral four digits
This is where the muscle exerts its action to extend the toes.
What is the innervation of Extensor digitorum longus?
Deep fibular nerve (L5, S1)
The deep fibular nerve enables the muscle’s function in toe extension.
What is the main action of Extensor digitorum longus?
Extends lateral four digits and dorsiflexes ankle joint
This muscle is important for activities that involve toe movement.
What is the proximal attachment of Extensor hallucis longus?
Middle part of anterior surface of fibula and interosseous membrane
This positioning aids in extending the great toe.
What is the distal attachment of Extensor hallucis longus?
Dorsal aspect of base of distal phalanx of great toe (hallux)
This attachment is crucial for the extension of the great toe.
What is the main action of Extensor hallucis longus?
Extends great toe and dorsiflexes ankle joint
This muscle is vital for proper gait and balance.
What is the proximal attachment of Fibularis tertius?
Inferior third of anterior surface of fibula and interosseous membrane
This unique attachment allows for its action in foot movement.
What is the distal attachment of Fibularis tertius?
Dorsum of base of 5th metatarsal
This attachment assists in the muscle’s role in foot eversion.
What is the main action of Fibularis tertius?
Dorsiflexes ankle joint and aids in eversion of subtalar joint
It supports lateral stability of the ankle.
What is the proximal attachment of Fibularis longus?
Head and superior two thirds of lateral surface of fibula
This attachment is essential for eversion actions.
What is the distal attachment of Fibularis longus?
Base of 1st metatarsal and medial cuneiform
This allows the muscle to contribute to foot stabilization.
What is the innervation of Fibularis longus?
Superficial fibular nerve (L5, S1, S2)
The superficial fibular nerve is critical for the muscle’s function.
What is the main action of Fibularis longus?
Everts subtalar joint and weakly plantarflexes ankle joint
This action is important for lateral stability during walking.
What is the proximal attachment of Fibularis brevis?
Inferior two thirds of lateral surface of fibula
This attachment supports the muscle’s role in foot eversion.
What is the distal attachment of Fibularis brevis?
Dorsal surface of tuberosity on lateral side of base of 5th metatarsal
This is where the muscle exerts its action for eversion.
What is the origin of the Abductor hallucis muscle?
Medial tubercle of tuberosity of calcaneus; flexor retinaculum; plantar aponeurosis
The Abductor hallucis is important for the movement of the great toe.
Where does the Abductor hallucis insert?
Medial side of base of proximal phalanx of 1st digit
This insertion allows for its function in toe movement.
Which nerve innervates the Abductor hallucis?
Medial plantar nerve (L5, S1)
Nerve innervation is crucial for muscle function.
What is the primary action of the Abductor hallucis?
Abducts and flexes 1st digit (great toe, hallux) at metatarsophalangeal (MTP) and interphalangeal (IP) joints
This action is essential for balance and walking.
What is the origin of the Flexor digitorum brevis muscle?
Medial tubercle of tuberosity of calcaneus; plantar aponeurosis; intermuscular septa
The origin contributes to its function in flexing the toes.
Where does the Flexor digitorum brevis insert?
Both sides of middle phalanges of lateral four digits
This allows it to flex multiple toes.
Which nerve innervates the Flexor digitorum brevis?
Medial plantar nerve (L5, S1)
Appropriate nerve supply is vital for muscle contraction.
What is the primary action of the Flexor digitorum brevis?
Flexes lateral four digits at MTP and IP joints
Important for gripping and balance.
What is the origin of the Abductor digiti minimi muscle?
Medial and lateral tubercles of tuberosity of calcaneus; plantar aponeurosis; intermuscular septa
The origin facilitates its role in little toe movement.
Where does the Abductor digiti minimi insert?
Lateral side of base of proximal phalanx of 5th digit
This insertion is crucial for its function.
Which nerve innervates the Abductor digiti minimi?
Lateral plantar nerve (S1–S3)
This innervation is essential for the muscle’s activity.
What is the primary action of the Abductor digiti minimi?
Abducts and flexes little toe (5th digit) at MTP and IP joints
This action aids in foot stability and balance.
What is the origin of the Quadratus plantae?
Medial surface and lateral margin of plantar surface of calcaneus
What is the insertion of the Quadratus plantae?
Posterolateral margin of tendon of flexor digitorum longus
Which nerve innervates the Quadratus plantae?
Lateral plantar nerve (S1–S3)
What is the function of the Quadratus plantae?
Assists flexor digitorum longus in flexing lateral four digits at MTP and IP joints
What is the origin of the Lumbricals?
Tendons of flexor digitorum longus
Where do the Lumbricals insert?
Medial aspect of expansion over lateral four digits
Which nerve innervates the medial Lumbrical?
Medial plantar nerve (L5–S1)
Which nerves innervate the lateral three Lumbricals?
Lateral plantar nerve (S1–S3)
What is the function of the Lumbricals?
Flex proximal IP joint; extend middle and distal IP joints of lateral four digits
What is the origin of the flexor hallucis brevis?
Plantar surfaces of cuboid and lateral cuneiforms
The flexor hallucis brevis is a muscle located in the foot.
Where does the flexor hallucis brevis insert?
Both sides of base of proximal phalanx of 1st digit
This muscle plays a role in the movement of the big toe.
Which nerve innervates the flexor hallucis brevis?
Medial plantar nerve (L5, S1)
This nerve is crucial for the sensory and motor functions of the foot.
What is the primary function of the flexor hallucis brevis?
Flexes proximal interphalangeal (IP) joint of 1st digit
This action is important for activities like walking and running.
What is the origin of the adductor hallucis oblique head?
Bases of metatarsals 2–4
This head contributes to the adduction of the first digit.
Where do the tendons of both heads of the adductor hallucis attach?
Lateral side of base of proximal phalanx of 1st digit
This attachment aids in the function of the muscle.
Which nerve innervates the adductor hallucis?
Deep branch of lateral plantar nerve (S1–S3)
This nerve is involved in the motor supply of the foot’s intrinsic muscles.
What is the traditional function of the adductor hallucis?
Adducts 1st digit; assists in maintaining transverse arch of foot
This function is critical for foot stability.
What is the origin of the transverse head of the adductor hallucis?
Plantar ligaments of metatarsophalangeal (MTP) joints
This head works alongside the oblique head for foot mechanics.
What is the origin of the flexor digit minimi brevis?
Base of 5th metatarsal
This muscle is specifically involved in the movement of the little toe.
Where does the flexor digit minimi brevis insert?
Base of proximal phalanx of 5th digit
This insertion allows for flexion of the little toe.
Which nerve innervates the flexor digit minimi brevis?
Superficial branch of lateral plantar nerve (S1–S3)
This nerve is responsible for the motor supply to the muscle.
What is the primary function of the flexor digit minimi brevis?
Flexes proximal IP joint of 5th digit
This function aids in the flexion of the fifth digit.
