LOWER LIMBS OVERVIEW

Lower limb attachment

Connects to axial skeleton via sacroiliac joint and pelvic ligaments.

Boundary from abdomen

Pubic tubercle → ASIS → iliac crest → PSIS.

Boundary from back

PSIS → dorsolateral sacrum → coccyx.

Boundary from perineum

Sacrotuberous ligament → ischial tuberosity → ischiopubic ramus → pubic symphysis.

Gluteal region

Posterolateral area from iliac crest to gluteal fold.

Anterior thigh

Inguinal ligament to knee joint.

Posterior thigh

Gluteal fold to knee.

Leg region

Knee to ankle.

Foot region

Distal to ankle.

Femoral triangle

Passageway for femoral nerve, artery, vein.

Popliteal fossa

Posterior knee passage for major nerves/vessels.

Tarsal tunnel

Posteromedial ankle tunnel for flexors, vessels, nerves.

Center of gravity

Slightly anterior to S2 vertebra.

Line of gravity

Posterior to hip, anterior to knee, anterior to ankle.

Knee locking

Small rotation stabilizes knee in extension.

Hip movements

Flexion, extension, abduction, adduction, rotation, circumduction.

Knee movements

Flexion and extension (+ slight rotation).

Ankle movements

Dorsiflexion and plantarflexion.

Walking efficiency

Pelvic tilt, pelvic rotation, slight knee flexion, knees inward.

Hip joint

Ball-and-socket between pelvic bone and femur.

Femur distal articulations

Tibia (knee) + patella.

Patella

Largest sesamoid bone in quadriceps tendon.

Tibia

Medial weight-bearing bone.

Fibula

Lateral non

Interosseous membrane

Connects tibia and fibula.

Talus recess

Tibia + fibula form socket for talus.

Ankle stability

Most stable in dorsiflexion.

Tarsal bones

Seven bones allowing inversion/eversion.

Metatarsals

Five long foot bones.

Phalanges

Three per toe except big toe (two).

Foot arches

Longitudinal (medial high) + transverse arches.

Gluteus maximus

Main hip extensor.

Gluteus medius/minimus

Hip abductors + pelvis stabilizers.

Deep gluteal muscles

Hip rotators.

Iliopsoas

Primary hip flexor.

Quadriceps femoris

Main knee extensor.

Medial thigh muscles

Hip adductors.

Hamstrings

Hip extension + knee flexion.

Anterior leg compartment

Dorsiflexes ankle + extends digits.

Lateral leg compartment

Everts foot.

Posterior leg compartment

Plantarflexes foot + flexes digits.

Intrinsic foot muscles

Support arches + assist push-off.

Inguinal gap

Passage for iliopsoas, femoral nerve, femoral vessels, lymphatics.

Greater sciatic foramen

Piriformis, sciatic nerve, gluteal nerves/vessels.

Obturator canal

Obturator nerve + vessels.

Lesser sciatic foramen

Obturator internus tendon + pudendal nerve.

Lumbar plexus

L1

Sacral plexus

L4

Dermatome L1

Inguinal ligament.

Dermatome L2

Lateral thigh.

Dermatome L3

Lower medial thigh.

Dermatome L4

Medial great toe.

Dermatome L5

Medial digit II.

Dermatome S1

Little toe.

Dermatome S2

Back of thigh.

Dermatome S3

Gluteal fold.

Dermatomes S4

S5

Hip flexion myotome

L1

Knee extension myotome

L3

Knee flexion myotome

L5

Plantarflexion myotome

S1

Toe adduction myotome

S2

Patellar reflex

L3

Achilles reflex

S1

Femoral nerve motor

Anterior thigh muscles.

Obturator nerve motor

Medial thigh muscles.

Superior gluteal nerve

Gluteus medius/minimus + TFL.

Inferior gluteal nerve

Gluteus maximus.

Tibial division of sciatic

Posterior thigh, posterior leg, sole.

Common fibular division

Anterior leg, lateral leg, dorsum foot.

TFL exception

Innervated by superior gluteal nerve.

Pectineus exception

Innervated by femoral nerve.

Adductor magnus exception

Hamstring part by tibial nerve.

Short head biceps femoris

Common fibular nerve.

Femoral nerve sensory

Anterior thigh, medial leg, medial ankle.

Obturator nerve sensory

Medial thigh.

Tibial nerve sensory

Lateral ankle, foot.

Common fibular nerve sensory

Lateral leg, dorsum foot.

Common fibular nerve injury

Vulnerable at fibular neck → foot drop.

Great saphenous vein

Medial vein draining to femoral vein.

Small saphenous vein

Posterior leg vein draining to popliteal vein.