Flashcards GPT: Lower Limb Muscles: Actions, Innervations, and Visual Cues

Comprehensive vocabulary flashcards covering the lower limb muscles, including their compartments, actions, segmental innervations, and visual or mnemonic identification cues.

Gluteal Compartment (Pattern)

Main action: Hip extension/abduction/rotation; Typical innervation: Gluteal nerves; deep-rotator branches.

Anterior Thigh Compartment (Pattern)

Main action: Knee extension; hip flexion; Typical innervation: Femoral nerve.

Medial Thigh Compartment (Pattern)

Main action: Hip adduction; Typical innervation: Obturator nerve; pectineus variable.

Posterior Thigh Compartment (Pattern)

Main action: Hip extension/knee flexion; Typical innervation: Sciatic divisions.

Anterior Leg Compartment (Pattern)

Main action: Dorsiflexion/toe extension; Typical innervation: Deep fibular.

Lateral Leg Compartment (Pattern)

Main action: Eversion; Typical innervation: Superficial fibular.

Posterior Leg Compartment (Pattern)

Main action: Plantarflexion/inversion/toe flexion; Typical innervation: Tibial.

Intrinsic Foot Compartment (Pattern)

Main action: Toe movements/arch support; Typical innervation: Medial and lateral plantar.

Gluteus maximus

Action: Hip extension, lateral rotation. Nerve: Inferior gluteal (L5–S2). Visual cue / mnemonic: Large superficial buttock muscle; cue: Max powers rising/climbing.

Gluteus medius

Action: Abduction; anterior fibers medially rotate; stabilizes pelvis. Nerve: Superior gluteal (L4–S1). Visual cue / mnemonic: Fan-shaped lateral hip; cue: keeps pelvis level in single-leg stance.

Gluteus minimus

Action: Abduction, medial rotation, pelvic stabilization. Nerve: Superior gluteal (L4–S1). Visual cue / mnemonic: Deep to medius; medius + minimus maintain pelvic level.

Tensor fasciae latae

Action: Hip flexion, abduction, medial rotation; tensions IT tract. Nerve: Superior gluteal (L4–S1). Visual cue / mnemonic: Anterolateral hip blending into IT band; TFL = Tenses Fascia Lata.

Piriformis

Action: Lateral rotation of extended hip; abducts flexed hip. Nerve: Nerve to piriformis (S1–S2). Visual cue / mnemonic: Deep posterior hip; part of deep lateral rotator group.

Obturator internus

Action: Lateral rotation; abducts flexed hip. Nerve: Nerve to obturator internus (L5–S2). Visual cue / mnemonic: Tendon turns around lesser sciatic notch.

Superior gemellus

Action: Assists lateral rotation and abduction of flexed hip. Nerve: Nerve to obturator internus (L5–S2). Visual cue / mnemonic: Small muscle above obturator internus tendon.

Inferior gemellus

Action: Assists lateral rotation and abduction of flexed hip. Nerve: Nerve to quadratus femoris (L4–S1). Visual cue / mnemonic: Small muscle below obturator internus tendon.

Quadratus femoris

Action: Lateral rotation; weak adduction. Nerve: Nerve to quadratus femoris (L4–S1). Visual cue / mnemonic: Rectangular deep muscle; a strong lateral rotator.

Obturator externus

Action: Lateral rotation; stabilizes femoral head. Nerve: Obturator (L3–L4). Visual cue / mnemonic: Deep muscle around external obturator membrane.

Iliacus

Action: Hip flexion. Nerve: Femoral (L2–L3). Visual cue / mnemonic: Fills iliac fossa; joins psoas as iliopsoas.

Psoas major

Action: Hip flexion; trunk flexion if femur fixed. Nerve: Anterior rami L1–L3 (sometimes L4). Visual cue / mnemonic: Along lumbar vertebrae; iliopsoas is powerful hip flexor.

Sartorius

Action: Hip flexion, abduction, lateral rotation; knee flexion. Nerve: Femoral (L2–L3). Visual cue / mnemonic: Long diagonal strap ASIS to medial tibia; helps sit cross-legged.

Rectus femoris

Action: Knee extension and hip flexion. Nerve: Femoral (L2–L4). Visual cue / mnemonic: Quadriceps member crossing both hip and knee.

Vastus lateralis

Action: Knee extension. Nerve: Femoral (L2–L4). Visual cue / mnemonic: Large lateral quadriceps.

Vastus medialis

Action: Knee extension; medial patellar stability. Nerve: Femoral (L2–L4). Visual cue / mnemonic: Medial quadriceps; distal fibers help guide patella.

Vastus intermedius

Action: Knee extension. Nerve: Femoral (L2–L4). Visual cue / mnemonic: Deep to rectus femoris, between vasti.

Articularis genus

Action: Pulls suprapatellar bursa upward during extension. Nerve: Femoral (L2–L4). Visual cue / mnemonic: Small deep muscle above patella.

Pectineus

Action: Hip adduction and flexion. Nerve: Usually femoral (L2–L3); variable obturator contribution. Visual cue / mnemonic: Upper medial thigh; remember variable innervation.

Adductor longus

Action: Hip adduction; assists flexion. Nerve: Obturator, anterior division (L2–L4). Visual cue / mnemonic: Superficial triangular adductor.

Adductor brevis

Action: Hip adduction; assists flexion. Nerve: Obturator, anterior division (L2–L4). Visual cue / mnemonic: Deep to adductor longus.

Adductor magnus (adductor part)

Action: Powerful adduction; assists flexion. Nerve: Obturator, posterior division (L2–L4). Visual cue / mnemonic: Large broad medial muscle.

Adductor magnus (hamstring part)

Action: Hip extension. Nerve: Tibial division of sciatic (usually L4). Visual cue / mnemonic: Two parts, two nerve supplies.

Gracilis

Action: Hip adduction; knee flexion; medial rotation of flexed leg. Nerve: Obturator, anterior division (L2–L3). Visual cue / mnemonic: Thin medial strap; joins pes anserinus.

Biceps femoris, long head

Action: Hip extension; knee flexion; lateral rotation of flexed leg. Nerve: Tibial division of sciatic (L5–S2). Visual cue / mnemonic: Lateral hamstring; crosses hip and knee.

Biceps femoris, short head

Action: Knee flexion; lateral rotation; no hip extension. Nerve: Common fibular division of sciatic (L5–S2). Visual cue / mnemonic: Hamstring exception: common fibular division.

Semitendinosus

Action: Hip extension; knee flexion; medial rotation of flexed leg. Nerve: Tibial division of sciatic (L5–S2). Visual cue / mnemonic: Superficial medial hamstring; long distal tendon.

Semimembranosus

Action: Hip extension; knee flexion; medial rotation of flexed leg. Nerve: Tibial division of sciatic (L5–S2). Visual cue / mnemonic: Deep medial hamstring; broad proximal tendon.

Tibialis anterior

Action: Dorsiflexion and inversion; medial arch support. Nerve: Deep fibular (L4–L5). Visual cue / mnemonic: Beside tibial crest. Cue: toes up, foot inward.

Extensor hallucis longus

Action: Great-toe extension; dorsiflexion. Nerve: Deep fibular (L5). Visual cue / mnemonic: Tendon to distal phalanx of hallux.

Extensor digitorum longus

Action: Extends toes 2–5; dorsiflexion; assists eversion. Nerve: Deep fibular (L5–S1). Visual cue / mnemonic: Four tendons to toes 2–5.

Fibularis tertius

Action: Dorsiflexion and eversion. Nerve: Deep fibular (L5–S1). Visual cue / mnemonic: Small distal anterior muscle to fifth metatarsal.

Fibularis longus

Action: Eversion; weak plantarflexion; supports arches. Nerve: Superficial fibular (L5–S2). Visual cue / mnemonic: Tendon passes behind lateral malleolus and under foot.

Fibularis brevis

Action: Eversion; weak plantarflexion. Nerve: Superficial fibular (L5–S2). Visual cue / mnemonic: Inserts at base of fifth metatarsal.

Gastrocnemius

Action: Plantarflexion; knee flexion. Nerve: Tibial (S1–S2). Visual cue / mnemonic: Two calf heads; crosses knee and ankle.

Soleus

Action: Powerful postural plantarflexion. Nerve: Tibial (S1–S2). Visual cue / mnemonic: Broad deep calf; standing muscle, does not cross knee.

Plantaris

Action: Weak plantarflexion and knee flexion. Nerve: Tibial (S1–S2). Visual cue / mnemonic: Small muscle with long thin tendon; may be absent.

Popliteus

Action: Unlocks knee; rotates tibia medially in open chain. Nerve: Tibial (L4–S1). Visual cue / mnemonic: Small triangular muscle behind knee.

Tibialis posterior

Action: Plantarflexion, inversion; medial arch support. Nerve: Tibial (L4–L5). Visual cue / mnemonic: Tendon passes behind medial malleolus.

Flexor hallucis longus

Action: Great-toe flexion; assists plantarflexion/push-off. Nerve: Tibial (S2–S3). Visual cue / mnemonic: Tendon to hallux; important in toe-off.

Flexor digitorum longus

Action: Flexes toes 2–5; assists plantarflexion. Nerve: Tibial (S2–S3). Visual cue / mnemonic: Tendons to distal phalanges of toes 2–5.

Extensor digitorum brevis

Action: Assists extension of toes 2–4. Nerve: Deep fibular (L5–S1). Visual cue / mnemonic: Small dorsolateral foot muscle.

Extensor hallucis brevis

Action: Extends great toe at MTP joint. Nerve: Deep fibular (L5–S1). Visual cue / mnemonic: Medial part of extensor digitorum brevis.

Abductor hallucis

Action: Abducts/flexes great toe; supports medial arch. Nerve: Medial plantar (S2–S3). Visual cue / mnemonic: Superficial medial sole; first layer.

Flexor digitorum brevis

Action: Flexes toes 2–5 at PIP joints. Nerve: Medial plantar (S2–S3). Visual cue / mnemonic: Central superficial sole; first layer.

Abductor digiti minimi

Action: Abducts/flexes fifth toe. Nerve: Lateral plantar (S2–S3). Visual cue / mnemonic: Superficial lateral sole; first layer.

Quadratus plantae

Action: Assists FDL; straightens its pull. Nerve: Lateral plantar (S2–S3). Visual cue / mnemonic: Second layer; FDL helper.

Lumbricals (4)

Action: Flex MTP and extend IP joints of toes 2–5. Nerve: 1st medial plantar; 2nd–4th lateral plantar. Visual cue / mnemonic: MTP flex, IP extend.

Flexor hallucis brevis

Action: Flexes great toe at MTP joint. Nerve: Medial plantar (S2–S3), usually. Visual cue / mnemonic: Third layer under first metatarsal.

Adductor hallucis

Action: Adducts great toe; supports transverse arch. Nerve: Deep lateral plantar (S2–S3). Visual cue / mnemonic: Oblique and transverse heads.

Flexor digiti minimi brevis

Action: Flexes fifth toe at MTP joint. Nerve: Superficial lateral plantar (S2–S3). Visual cue / mnemonic: Third layer under fifth metatarsal.

Plantar interossei (3)

Action: Adduct toes 3–5; assist MTP flexion/IP extension. Nerve: Deep lateral plantar (S2–S3). Visual cue / mnemonic: PAD = Plantar ADduct.

Dorsal interossei (4)

Action: Abduct toes 2–4; assist MTP flexion/IP extension. Nerve: Deep lateral plantar (S2–S3). Visual cue / mnemonic: DAB = Dorsal ABduct.

Pes anserinus

Anatomical convergence at the medial tibia consisting of three muscles: Sartorius, Gracilis, and Semitendinosus.