FUNTIONAL HUMAN ANATOMY LAB #8 LOWER EXTREMITY MUSCULATURE The following tips will help you in naming the muscles of the leg and foot: The Tibia is located on the medial side of the leg. The Fibula is located on the lateral side of the leg. The anterior side of the leg and the dorsal side of the foot contain muscles that perform extension or dorsiflexion and may have extensor in the name. The posterior side of the leg and the plantar side of the foot contain muscles that perform flexion or plantarflexion and may have flexor in the name. Any muscle that attaches to the 1 st digit (hallux big toe) has Hallicus in the name Any muscle that attaches to the 2 nd digit (index finger) has Indicis in the name Any muscle that attaches to the 5 th digit (pinky finger) has Digiti Minimi in the name Any muscle that attaches to all of the digits (2-5) has Digitorum in the name Muscles that pass the malleoli posteriorly perform plantarflexion Muscles that pass the malleoli anteriorly perform dorsiflexion Muscles that pass the malleoli medially perform inversion Muscles that pass the malleoli laterally perform eversion GLUTEAL REGION: Gluteus maximus largest/strongest muscle in the body gluteal surface of ilium, dorsal side of sacrum and coccyx, sacrotuberous ligament superior 2/3 IT (iliotibial) band inferior 1/3 gluteal tuberosity Extension, hyperextension and external rotation of the thigh/trunk at the hip, Gluteus medius deep to gluteus maximus gluteal surface of ilium lateral surface of greater trochanter of femur Abduction of the thigh/trunk at the hip 1
Gluteus minimus deep to gluteus medius gluteal surface of ilium anterior surface of greater trochanter of femur Flexion and internal rotation of the thigh/trunk at the hip Piriformis hip stabilizer muscle (1 of 6); sciatic nerve may occasionally pierce this muscle; can be source of chronic sciatic pain; locate just superior to sciatic nerve as it emerges from greater sciatic foramen anterior surface of sacrum between S2 & S4 superior border of greater trochanter of femur Lateral rotation of the thigh/trunk at the hip Superior gemellus hip stabilizer muscle (2 of 6); locate just inferior to sciatic nerve as it emerges from greater sciatic foramen ischial spine trochanteric fossa of femur; common attachment point with inferior gemellus and obturator internus Lateral rotation of the thigh/trunk at the hip Obturator internus hip stabilizer muscle (3 of 6); located between superior and interior gemellus (only tendon is visible as it emerges from lesser sciatic foramen) posterior side of obturator foramen trochanteric fossa of femur; common attachment point with inferior gemellus and obturator internus Lateral rotation of the thigh/trunk at the hip 2
Inferior gemellus hip stabilizer muscle (4 of 6); locate just inferior to obturator internus tendon ischial tuberosity Lab 8 trochanteric fossa of femur; common attachment point with inferior gemellus and obturator internus Lateral rotation of the thigh/trunk at the hip Quadratus femoris hip stabilizer muscle (5 of 6); locate lateral border of ischial tuberosity just inferior to inferior gemellus intertrochanteric crest Lateral rotation of the thigh/trunk at the hip Obturator externus hip stabilizer muscle (6 of 6); locate on anterior side deep to pectineus; locate on posterior side deep to quadratus femoris anterior side of obturator foramen trochanteric fossa of femur Lateral rotation of the thigh/trunk at the hip POSTERIOR THIGH Biceps femoris hamstring muscle (1 of 3); lateral posterior thigh muscle; consists of long and short heads (anatomical) long head ischial tuberosity short head distal half of linea aspera both heads lateral side of head of fibula Extension, hyperextension and external rotation of the thigh/trunk at the hip. Flexion of the leg at the knee 3
Semitendinosus hamstring muscle (2 of 3); medial posterior thigh muscle; locate superficial to semimembranosus ischial tuberosity medial surface of proximal end of tibia Extension, hyperextension and internal rotation of the thigh/trunk at the hip. Flexion of the leg at the knee Semimembranosus hamstring muscle (3 of 3); medial posterior thigh muscle; locate deep to semitendinosus ischial tuberosity posterior side of medial condyle of tibia Extension, hyperextension and internal rotation of the thigh/trunk at the hip. Flexion of the leg at the knee ANTERIOR THIGH Iliacus locate in the abdomen in the iliac fossa; passes under inguinal ligament iliac fossa and iliac crest body of femur inferior to lesser trochanter, common attachment with psoas major Flexion of the thigh/trunk at the hip Psoas major locate in the abdomen medial to iliacus; passes under inguinal ligament lateral sides of bodies of T12 - L5 body of femur inferior to lesser trochanter, common attachment with iliacus Flexion of the thigh/trunk at the hip 4
Psoas minor locate in the abdomen medial to iliacus; distal attachment does not extend to the femur lateral sides of bodies of T12 L1 iliopectineal eminence Flexion of the lumbar vertebre Rectus femoris quadracep muscle (1 of 4); only quadracep muscle that spans 2 joints anterior inferior iliac spine patellar (quadraceps) tendon to patella to patellar (quadraceps) ligament to tibial tuberosity; common to all 4 quadracep muscles Flexion of the thigh/trunk at the hip. Extension of the leg at the knee Vastus lateralis quadracep muscle (2 of 4); locate lateral to rectus femoris lateral side of body of femur patellar (quadraceps) tendon to patella to patellar (quadraceps) ligament to tibial tuberosity; common to all 4 quadracep muscles Extension of the leg at the knee Vastus medialis quadracep muscle (3 of 4); locate medial to rectus femoris medial side of body of femur patellar (quadraceps) tendon to patella to patellar (quadraceps) ligament to tibial tuberosity; common to all 4 quadracep muscles Extension of the leg at the knee 5
Vastus intermedius quadracep muscle (4 of 4); locate deep to rectus femoris anterior surface of body of femur patellar (quadraceps) tendon to patella to patellar (quadraceps) ligament to tibial tuberosity; common to all 4 quadracep muscles Extension of the leg at the knee Tensor fasciae latae marks the division between anterior and posterior thigh muscles anterior superior iliac spine; anterior part of iliac crest IT band to anterior surface of lateral condyle of tibia Abduction and flexion of the thigh/trunk at the hip. Sartorius longest muscle in the body; characteristic S shape anterior superior iliac spine anterior surface of medial condyle of tibia; common attachment with gracilis Flexion and lateral rotation of the thigh/trunk at the hip. Flexion of the leg at the knee MEDIAL THIGH Pectineus locate just medial to the anterior thigh vasculature superior pubic ramus pectineal line of femur (proximal end of linea aspera) Adduction and lateral rotation of the thigh/trunk at the hip 6
Adductor longus locate medial to pectineus body of pubis middle of linea aspera of femur Adduction and lateral rotation of the thigh/trunk at the hip Adductor brevis locate deep to pectineus and adductor longus inferior pubic ramus proximal part of linea aspera of femur Adduction and lateral rotation of the thigh/trunk at the hip Adductor magnus largest muscle in the thigh inferior pubic ramus and ischial tuberosity length of linea aspera of femur (hamstring part) and adductor tubercle of femur (adductor part) Adduction and lateral rotation of the thigh/trunk at the hip Gracilis most medial thigh muscle; division between anterior and posterior thigh muscles inferior pubic ramus anterior surface of medial condyle of tibia; common attachment with sartorius Adduction and medial rotation of the thigh/trunk at the hip 7
GENERAL INNERVATION OF THE THIGH/GLUTEAL REGION Muscles of ANTERIOR thigh - Femoral N. Muscles of GLUTEAL thigh Superior/Inferior Gluteal N. Muscles of MEDIAL thigh - Obturator N. Muscles of POSTERIOR thigh - Sciatic N. (tibial & fibular divisions) ANTERIOR LEG Tibialis anterior locate on lateral side of shin lateral condyle of tibia and lateral suface of tibia base of 1 st metatarsal Dorsiflexion and inversion of the foot at the ankle Extensor hallucis longus passes anterior to the malleoli; locate deep to tibialis anterior anterior surface of body of fibula base of distal phalanx of hallux Dorsiflexion and inversion of the foot at the ankle. Extension of the 1 st digit Extensor digitorum longus passes anterior to the malleoli; locate deep to tibialis anterior head of fibula middle and distal phalanges of 2 nd - 5 th digits Dorsiflexion of the foot at the ankle. Extension of digits 2-5 8
Fibularis tertius passes lateral malleolus anteriorly; will appear to be continuous with extensor digitorum longus anterior surface of body of fibula base of 5 th metatarsal Dorsiflexion and eversion of the foot at the ankle POSTERIOR LATERAL LEG Fibularis longus locate superficial to fibularis brevis; passes lateral malleolus posteriorly head of fibula base of 1 st metatarsal (after wrapping around 5 th metatarsal) Plantarflexion and eversion of the foot at the ankle Fibularis brevis locate deep to fibularis longus; passes lateral malleolus posteriorly lateral surface of body of fibula base of 5 th metatarsal Plantarflexion and eversion of the foot at the ankle POSTERIOR LEG Gastrocnemius most superficial posterior leg muscle; consists of medial and lateral heads (anatomical) superior to posterior surface of lateral and medial condyles of tibia tendo calcaneus (achilles tendon) to tuberosity of calcaneus Flexion of the leg at the knee. Plantarflexion of the foot at the ankle 9
Plantaris very small muscle located between gastrocnemius and soleus Lab 8 same as lateral head of gastrocnemius same as gastrocnemius Flexion of the leg at the knee. Plantarflexion of the foot at the ankle Soleus consists of primarily ST muscle fibers head of fibula same as gastrocnemius Plantarflexion of the foot at the ankle Popliteus deepest posterior leg muscle; helps unlock the knee lateral epicondyle of femur proximal end of tibia on the medial side Unlocks the knee from a fully extended position POSTERIOR MEDIAL LEG Tibialis posterior locate deep to soleus posterior surface of body of tibia and fibula base of 2 nd, 3 rd and 4 th metatarsals Plantarflexion and inversion of the foot at the ankle 10
Flexor digitorum longus locate deep to soleus posterior surface of tibia distal phalanges of 2 nd - 5 th digits Plantarflexion and inversion of the foot at the ankle. Flexion of the digits Flexor hallucis longus locate deep to soleus posterior surface of body of fibula base of distal phalanx of hallux Plantarflexion and inversion of the foot at the ankle. Flexion of the 1 st digit DORSAL FOOT Extensor digitorum brevis locate deep to extensor digitorum longus tendons Extension of digits 2-5 Extensor hallucis brevis locate deep to extensor digitorum longus tendons Extension of the 1 st digit Dorsal interosseus locate between 1 st - 5 th metatarsals Abduction of all of the digits 11
PLANTAR FOOT Abductor hallucis locate in medial plantar eminence; most medial muscle of the foot Abduction of the 1 st digit Flexor hallucis brevis locate in medial plantar eminence; just lateral to abductor hallucis Flexion of the 1 st digit Abductor digiti minimi locate in lateral plantar eminence; most lateral muscle of the foot Abduction of the 5 th digit Flexor digiti minimi locate in lateral plantar eminence; Flexion of the 5 th digit just medial to abductor digiti minimi Flexor digitorum brevis covered by plantar aponeurosis Flexion of digits 2-5 Adductor hallucis consists of oblique and transverse heads Adduction of the 1 st digit 12
Quadratus plantae locate proximal to the lateral side of flexor digitorum longus tendon Fixes the tracking of the flexor digitorum longus tendon so that the digits are flexed evenly Lumbrical locate along side tendons for flexor digitorum longus Flexion of the metatarsals while simultaneously extending or hyperextending the phlanges Plantar interosseus locate between the 2 nd - 5 th metatarsals Adduction of all of the digits GENERAL INNERVATION OF THE LEG REGION Muscles of ANTERIOR leg deep fibular N. Muscles of LATERAL leg superficial fibular N. Muscles of POSTERIOR leg tibial N. 13