Lower Limbs

Quadriceps femoris

• Anterior compartment of thigh

• Four separate muscles: distal tendon unites to envelop the patella and attach to the tibial tuberosity

• Most muscles are flexors of the thigh and extensors of the knee (squats)

• Muscles will atrophy very quickly with disuse

• Quadriceps tendon envelopes patella inserts on the tibial tubersity

  • Q angle of VMO

  • Women have wider pelvises → puts outside of femur at stronger angle (Q angle) to the patella, where pulling causes lateral tracking of the patella

  • ACL injuries more common in women

• Rectus femoris

  • Actions

    • Flexes hip

    • Extends knee

  • Innervation → femoral nerve

  • Only quad to cross two joints (hip and knee)

• Vastus lateralis

  • Actions

    • Extends and stabilizes knee

  • Innervation → femoral nerve

• Vastus medialis

  • Actions

    • Patellar tracking on the patellar surface of the femur (can strengthen vastus medialis to assist in patella tracking)

    • Extends and stabilizes knee

  • Innervation → femoral nerve

• Vastus intermedius

  • Actions

    • Extends and stabilizes knee

  • Innervation → femoral nerve

Tensor fascia lata

• Anterior compartment of thigh (lateral)

• Anterior part of shared iliotibial track

• Only superior: continuation is iliotibial band

• Actions

  • Abducts and medially rotates thigh

  • Flexes the thigh a bit (crosses over the hip joint)

  • Continues as iliotibial track

• Innervation → superior gluteal nerve

Psoas major

• Anterior thigh compartment lateral

• With iliacus → iliospoas (goes onto lesser trochanteric)

• Only muscle attached to spine, pelvis, and femur

• Actions

  • Major hip flexor

  • Hip stabilizer when going down stairs/big inclines

  • Flexes and rotates trunk because of piece in the abdomen

• Innervation → anterior rami L1-3

Sartorius

• Anterior thigh compartment superficial

• Comes across anterior thigh and attaches distally at medial tibia

• Mostly a synergist: not a primary mover

• Actions

  • Abducts hip

  • Flexes hip

  • Laterally rotates hip

  • Flexes knee

  • Figure 4/Tailor muscle

• Innervation → femoral nerve

Pectineus

Anterior thigh compartment medial

Smallest of adductors

Goes from pubis over to the proximal femur

Actions

• Adduction of thigh

• Flexion of thigh

• Medial rotation of thigh

Innervation → femoral nerve (some obturator nerve)

• Dual innervation due to embryology

Adductor Longus

Anterior compartment of the thigh medial

Medial to pectinous

Attached to the line aspera

Actions

• Adducts hip

Innervation

• Obturator nerve

Adductor brevis

Anterior compartment of the thigh medial

Actions

• Adducts hip

Innervation

• Obturator nerve

Adductor magnus

Posterior compartment of the thigh medial (seen from the posterior view)

Thought of as fourth hamstring

Piece that goes to ischial tuberosity

Actions

• Adductor part: adducts and flexes hip

• hamstring part: extends hip

Innervation

• Obturator nerve → adductor

• Tibial nerve (posterior nerve) → hamstring

Gracilis

Anterior compartment of the thigh medial (can see from posterior view sometimes)

Runs from way up top to way beyond the knee and medial tibia

Crosses two joints

Actions

• Adducts thigh

• Flexes and medially rotates knee

  • Cruciate ligaments try to stop medial rotation

Innervation

• Obturator nerve

Femoral Triangle

Used to get into femoral artery and femoral vein

Bounded by

• Inguinal ligament superiorly

• Sartorius laterally

• Adductor longus laterally

Floor

• Iliopsoas lateral

• Pectineus medial

• Forms a V

  • Between the V have cluster of femoral artery, nerve, and vein

Contains: NAV L (from lateral to medial)

• Femoral nerve: find a broom

• Femoral artery

  • May see artery just a little bit more superficial

• Femoral vein (receives great saphenous vein)

• Femoral lymphatics

Femoral sheath

Contains

• Femoral artery and branches

• Femoral vein

Hamstrings

Posterior compartment of the thigh

Attach proximally to ischial tuberosity

Contains

• Semitendinosis

  • Medial

  • Most superficial

  • Ends in long tendon

  • Sometimes used for ACL repair

• Semimembranosis

  • Medial

  • Immediately deep to semitendinosis

• Long head of biceps femoris

  • Lateral hamstring

Actions

• Hip extension

• Knee flexion

Innervation

• Tibial branches of sciatic nerve

Short head of biceps femoris

Posterior compartment of the thigh

Not a hamstring

Comes off of shaft of femur and attaches to head of the fibula

Action

• Flexion of knee (does assist in long head thigh extension)

Innervation

• Common fibular nerve of sciatic

Popliteal fossa

Posterior

Bounded by

• Semitendinosis/membranosis: medial

• Biceps femoris: lateral

• Lateral head gastrocnemius: inferior

• Medial head gastrocnemius: inferior

Base

• Femur and tibia

• Posterior capsule of knee

• Popliteus muscle

  • Attaches to lateral meniscus and goes from lateral to medial

  • Rotates femur laterally or tibia to medially unlock the knee to flex

  • Innervated by branch to common fibular nerve that is going anteriorly

  • Can pull the muscle in hyperextended position → pain behind the knee

Contents

• Fat

• Small saphenous vein

• Popliteal artery and vein: can palpate pulse

• Tibial nerve with common fibular nerve branch

• Cutaneous nerves

• Lymph nodes

Can have deep venous thrombosis

Gastrocnemius, soleus, and plantaris

Posterior compartment of leg superficial

Gastrocnemius

• Lateral and medial head with vessel going in between them → small saphenous vein

• Crosses the knee

• Fabella

  • Sesmoid bone at origin of lateral head

  • In up to 5% of people

Soleus

• Deep to gastrocnemius

Plantaris

• Leg equivalent to palmaris longus

• Used for tendon transplant

• In between

All three cross the ankle → common tendon is achilles tendon

Actions

• Plantar flexion

• Gastrocnemius: flexes knee

Innervation

• Tibial nerve

Artery

• Posterior tibial branches

  • Fibular aa

Tibialis posterior

Posterior compartment of leg deep

Immediately posterior to tibia and attaches to naviculum

Most anterior of the three

Actions

• Plantar flexion

• Works with tibialis anterior to invert

• Arch maintenance during weight bearing

Innervation

• Tibial nerve

Artery

• Fibular artery

• Posterior tibial artery

Flexor hallucis longus

Posterior compartment of leg deep

Make sure that there is a tendon going to plantar aspect of great toe and first muscle to see in the deep posterior compartment

• Big because it is used every time we ambulate: push off muscle

• Tibial nerve and posterior tibial artery very close by

• Immediately next to: flexor digitorum and then tibialis posterior

Attaches to base of distal of great hallus

Actions

• Plantar flexion

• Flexes great toe

Innervation

• Tibial nerve

Artery

• Fibular artery

• Posterior tibial artery

Flexor digitorum longus

Posterior compartment of leg deep

Attaches to bases of lateral distal phalanges

Actions

• Plantar flexion

• Flexes digits 2-5

Innervation

• Tibial nerve

Artery

• Fibular artery

• Posterior tibial artery

Tibialis anterior

Anterior compartment of the leg

Inserts onto base of first metatarsal

Actions

• Dorsiflexion (strongest)

• Synergistic inversion

• Important in arch formation

Indicated in shin splints

• Muscle filled with blood and compartment cannot account for it: temprary compartment syndrome

• Test → stand on heels

Innervation

• Deep fibular (peroneal) nerve

Artery

• Anterior tibial artery

Extensor digitorum longus

Anterior compartment of the leg

Most lateral in compartment

Actions

• Dorsiflexion

• Extension of digits 2-5

Innervation

• Deep fibular nerve

Artery

• Anterior tibial artery

Extensor hallicus longus

Anterior compartment of the leg

Deep between TA and EDL: follow it to great toe

Actions

• Dorsiflexion (strongest)

• Extension of great toe

Innervation

• Deep fibular nerve

Artery

• Anterior tibial artery

Fibularis tertius

Anterior compartment of the leg

Not always present

Actions

• Dorsiflexion

Innervation

• Deep fibular nerve

Not always present

Fibularis brevis and longus

Lateral compartment of the leg

Brevis

• Lie over fibula

• Attaches to base of 5th metatarsal

  • When we sprain our ankle we invert → everters on stretch → fracture base of the 5th metatarsal (most common fracture: avulsion because it was pulled off)

Longus

• Lie over fibula

• Most lateral

• Attaches on the medial side on the base of the 1st metatarsal

• Usually do not see avulsion

Actions

• Eversion

• Plantar flexion

• Maintains arch of foot

  • Injury → some loss of arch

Innervation

• Superficial peroneal nerve

Artery

• Branches of posterior and fibular arteries

Foot

• Four layers of muscles

• Support arches

• Minimal intrinsic function

• Nerves

  • Medial and lateral plantar (tibial)

    • Sensory and motor

  • Sural

    • Sensory and lateral

• Plantar fascia

  • From calcaneus to PIP joints

  • Support arches

  • Site of plantar fasciitis