1. Muscles of the legs

2. Superficial Muscles of the Body – Anterior View
Figure 11.7a

3. Superficial Muscles of the Body – Posterior View
Figure 11.7b

4. Muscle Compartments of the Thigh
Posterior compartment muscles
Extend the hip and flex the knee
Innervation is the tibial branch of the sciatic nerve
Anterior compartment muscles
Flex the hip and extend the knee
Innervation is the femoral nerve
Medial compartment
Adduct the thigh
Innervation is the obturator nerve

5. Compartments of the Leg
Posterior compartment muscles
Contains digital and plantar flexors
Innervation is the tibial nerve
Anterior compartment muscles
Contains digital extensors and dorsiflexors
Innervation is the deep fibular nerve
Lateral compartment muscles
Plantar flex and evert the foot
Innervation is the superficial fibular nerve

6. Muscle Compartments of the Thigh and Leg
Figure 11.6a

7. Muscle Compartments of the Thigh and Leg
Figure 11.6b

8. Muscles Crossing the Hip and Knee Joints
Thigh and leg movements
Anterior muscles
Flex the thigh and extend the leg at the knee
Posterior muscles
Extend the thigh and flex the leg

9. Muscles Crossing the Hip and Knee Joints
Thigh and leg movements
Adductor muscles – on medial aspect of thigh
Adduct the thigh only
Deep fascia of the thigh
Surrounds and encloses all three groups

10. Muscles Crossing the Hip and Knee Joints
Movements at the hip joint
Muscles that flex the thigh
Originate on vertebral column or pelvis
Muscles that extend the thigh
Arise posterior to the hip joint
Adductors originate medial to the hip joint
Abductors originate lateral to the hip joint

11. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg
Anterior and Medial Muscles (Pelvis or Backbone origin)
ATTACHMENT
MUSCLE ACTION (prime movers)
Muscle
Origin
Insertion
Action
Nerve Supply
Iliacus
Iliac fossa, sacral ala
Lesser trochanter of femur (via iliopsoas tendon)
Thigh and trunk flexion
Femoral n.
Psoas major
Transverse processes (fleshy strips), bodies; disc of Lumbar vert. & T12
Thigh and trunk flexion; and flexion of vertebral column
Ventral rami (L1 – L3)
Sartorius
Ant. Sup. Iliac spine
Medial knee & proximal tibia
Flex abducts and laterally rotates thigh; flexes knee
Iliopsoas

12. Anterior and Medial Muscles
Origin on pelvis or vertebral column
Iliacus
Psoas major
Sartorius
Muscles of the medial compartment
Adductor longus
Adductor brevis
Adductor magnus
Pectineus
Gracilis

13. Anterior and Medial Muscles
Figure 11.20a

14. Muscles of the Anterior Compartment of the Thigh
Quadriceps femoris
Has four separate heads
Has a common insertion at the quadriceps tendon
Powerful knee extensors
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Tensor fasciae latae

15. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg (Medial Thigh Muscles)
ATTACHMENT
MUSCLE ACTION (prime movers)
Muscles
Origin
Insertion F
Nerve Supply
Adductor longus
Pubis (near symphysis pubis)
Linea aspera
Adducts, flexes, and medially rotates thigh
Obturator n. (L2 – L4)
Adductor brevis
Body & inf. Pubic rami
Linea aspera (above adductor longus)
Adducts and medially rotates thigh
Obturator n.
Adductor magnus
Ischial and pubic rami & ischial tuberosity
Linea aspera; medial supracondylar line, adductor tubercle of femur
Anterior part- adducts and medially rotates and nflexes.
Posterior part- synergist with hamstring muscles in thigh extension
Obturator n. and Sciatic n. (L2 – L4)
Pectineus
Pectineal line of pubis and sup. ramus
From lesser trochanter to linea aspera
Femoral n. (sometimes Obturator n.)
Gracilis
Inf. Ramus & body of the pubis (and adjacent ischial ramus)
Medial tibial surface (inf. To medial condyle)
Adducts thigh, flexes, & medially rotates leg
Adductors

16. Muscles of the Anterior Compartment of the Thigh
Figure 11.20a

17. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg (Anterior Thigh Muscles)
ATTACHMENT
MUSCLE ACTION (prime movers)
Muscles
Origin
Insertion F
Nerve Supply
Rectus femoris
Ant. Inf. Iliac spine; & Sup. Margin of acetabulum
Patellar ligament (Patella and tibial tuberosity
Extends knee & flexes thigh at hip
Femoral n. (L2 – L4)
Vastus lateralis
Greater trochanter, intertrochanteric line, linea aspera
Patellar ligament (Patella and tibial tuberosity)
Extends and stabilizes thigh
Vastus medialis
Linea aspera, medial supracondylar line, intertrochanteric line
Extends knee
Vastus intermedius
Anterior and lateral surface of femur
Tensor fasciae latae
Anterior iliac crest & ant. sup. Iliax spine
Iliotibial tract (ensheaths all muscle of the thigh)
Steadies trunk on thigh (makes the iliotibial tract taut)
Superior gluteal n. (L4 – L5)
Quadriceps femoris

18. Posterior Muscles Origin on pelvis or sacrum Gluteus maximus
Gluteus medius
Gluteus minimus
Lateral rotators
Piriformis
Obturator externus
Obturator internus
Superior and inferior gemellus
Quadratus femoris
PLAY
Movement at the hip joint: an overview

19. Posterior Muscles
Figure 11.21b

20. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg (Posterior Muscles, Gluteal muscles)
POSTERIOR MUSCLES
ATTACHMENT (Origin on Pelvis or Sacrum)
MUSCLE ACTION (prime movers)
Gluteal Muscles
Origin
Insertion
Action
Nerve Supply
Gluteus maximus
Dorsal Ilium, sacrum, and coccyx
Gluteal tuberosity (femur); Iliotibial tract
Major extensor of thigh
Inferior gluteal n. (L5, S1, S2)
Gluteus medius
Between ant. And post. Gluteal lines (lateral ilium)
Lateral aspect of greater trochanter (femur)
Abducts and medially rotates thigh
Superior gluteal n. (L5, S1)
Gluteus minimus
Between ant. & inf. Gluteal lines on external surface of ilium
Ant. Border of greater trochanter of femur
As for gluteus medius

21. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg (Posterior Muscles, Lateral Rotators)
POSTERIOR MUSCLES
ATTACHMENT (Origin on Pelvis or Sacrum)
MUSCLE ACTION (prime movers)
Lateral Rotator Muscles
Origin
Insertion
Action
Nerve Supply
Piriformis
Anterolateral surface of sacrum
Sup. Border greater trochanter (femur)
Rotates extended thigh laterally
S1 and S2, L5
Obturator externus
Outer surface of obturator membrane; External surface of pubis and ischium and margins of obturator foramen
By a tendon into trochanteric fossa of posterior femur
As for piriformis
Obturator n.
Obturator internus
Inner surface of obturator membrane; greater sciatic notch; margins of obturator foramen
Greater trochanter (in front of piriformis)
L5 and S1
Gemellus
Superior- Ischial spine
Inferior- Ischial tuberosity
Greater trochanter (femur)
Quadratus femoris
Iscial tuberosity
Intertrochanteric crest (femur)
Rotates thigh laterally and stabilizes hip joint

22. Muscles of the Posterior Compartment of the Thigh
Hamstrings
Biceps femoris
Semitendinosus
Semimembranosus
Figure 11.21a

23. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg (Posterior Thigh Muscles)
ATTACHMENT
MUSCLE ACTION (prime movers)
Muscles
Origin
Insertion
Action
Nerve Supply
Biceps femoris
Long head- ischial tuberosity
Short head- Linea aspera, lateral supracondylar ridge, & distal femur
Common tendon at lateral border of popliteal fossa to insert into head of fibula and lateral condyle of tibia
Extends thigh and flexes knee
Sciatic n. (Tibial n. to long head; Common fibular n. to short head)
Semitendinosus
Ischial tuberosity (common w/ long head of biceps femoris)
Medial aspect of upper tibial shaft
Extends thigh at hip; flexes knee
Sciatic n. – tibial n. portion (L5 – S2)
Semimembranosus
Ischial tuberosity
Medial condyle of tibia
Hamstrings

24. Muscles of the Leg Fascia lata of the leg surrounds muscles
Tightly binds muscles
Prevents swelling during exercise
Aids venous return
Divides leg into three compartments
Tendons are held in place by
Extensor, fibular, and flexor retinacula
Muscle movement at ankle and intertarsal joints

25. Muscles of the Anterior Compartment
Tibialis anterior
Extensor digitorum longus
Fibularis (peroneus) tertius
Extensor hallucis longus
PLAY
Muscles of the ankle and foot (b)
Figure 11.22a

26. Muscles of the Leg: Movements of the Ankle and Toes
LEG MUSCLES
ATTACHMENT
MUSCLE ACTION (prime movers)
Anterior Compartment Muscles
Origin
Insertion
Action
Nerve Supply
Tibialis anterior
Lateral condyle & upper 2/3 of tibial shaft; interosseous membrane
By tendon into inferior surface of medial cuneiform and metatarsal 1
Prime mover of dorsiflexion
Deep fibular n. (L4 & L5)
Extensor digitorum longus
Lateral condyle of tibia; proximal ¾ of fibula; interosseous membrane
Middle & distal phalanges 2-5 (via extensor expansion)
Prime mover of toe extension
Deep fibular n. (L5 & S1)
Fibularis (peroneus) tertius
Distal anterior surface of fibula and interosseous membrane
Tendon inserts on dorsum of metatarsal 5
Dorsiflexes and everts foot
Extensor hallucis longus
Anteromedial fibula shaft and interosseous membrane
Tendon inserts on distal phalanx of great toe)
Extends great toe

27. Muscles of the Lateral Compartment
Fibularis (peroneus) longus
Fibularis (peroneus) brevis
Flexor hallucis longus
Extensor hallucis longus
Fibularis tertius
PLAY
Muscles of the ankle and foot (c)
Figure 11.23a

28. Muscles of the Lateral Compartment
Figure 11.23b, c

29. Muscles of the Leg: Movements of the Ankle and Toes (Lateral Compartment)
LEG MUSCLES
ATTACHMENT
MUSCLE ACTION (prime movers)
Lateral Compartment Muscles
Origin
Insertion
Action
Nerve Supply
Fibularis (peroneus) longus
Fibular head; upper & lateral fibula
By long tendon (curves under the foot) to Metatarsal 1 & medial cuneiform
Plantar flexion & everts foot
Superficial fibular n. (L5 – S2)
Fibularis (peroneus) brevis
Distal fibular shaft
By tendon (behind lateral malleolus) to proximal end of Metatarsal 5
Superficial fibular n.

30. Muscles of the Posterior Compartment
Superficial muscles
Triceps surae
Gastrocnemius
Soleus
Plantaris
PLAY
Muscles that act on the ankle and foot: an overview

31. Muscles of the Posterior Compartment
Figure 11.24a, b

32. Muscles of the Leg: Movements of the Ankle and Toes (Posterior Compartment, Superficial)
LEG MUSCLES
ATTACHMENT
MUSCLE ACTION (prime movers)
Posterior Compartment (Superficial) Muscles
Origin
Insertion
Action
Nerve Supply
Gastrocnemius (medial and lateral head)
2 heads from medial & lateral femoral condyle
Posterior calcaneus (via calcaneal tendon)
Plantar flexes foot
Tibial n. (S1 and S2)
Soleus
(Cone shaped) Superior tibia, fibula, & interosseous membrane
As for gastrocnemius
Tibial n.
Plantaris
Posterior femur (above lateral condyle)
(Via a long thin tendon) into calcaneus (or calcaneal tendon)
Assist in knee flexion and plantar flexion of foot
Triceps Surae

33. Muscles of the Posterior Compartment
Deep muscles
Popliteus
Flexor digitorum longus
Flexor hallucis longus
Tibialis posterior
PLAY
Muscles of the ankle and foot (a)
PLAY
Muscles of the ankle and foot (d)
Figure 11.24c

34. Muscles of the Leg: Movements of the Ankle and Toes (Posterior Compartment, Deep)
LEG MUSCLES
ATTACHMENT
MUSCLE ACTION (prime movers)
Posterior Compartment (Deep) Muscles
Origin
Insertion
Action
Nerve Supply
Popliteus
Lateral condyle (femur); Lateral meniscus (knee)
Proximal tibia
Flexes and rotates leg medially to unlock knee from full extension when flexion begins
Tibial n. (L4 – S1)
Flexor digitorum longus
(Extensive) Posterior tibia
(Tendon behind medial malleolus) into distal phalanges 2 - 5
Plantar flexes and inverts foot; flexes toes (“grips ground”)
Tibial n. (L5 – S2)
Flexor hallucis longus
Middle fibular shaft; interosseous membrane
(Tendon runs under foot) to distal phalanx of great toe
Plantar flexes and inverts foot; flexes great toe at all joints (“push off muscle during walking”)
Tibialis posterior
Superior tibia and fibula; interosseous membrane
(Tendon passes behind medial malleolus & under arch of foot) into several tarsals and metatarsals 2 - 4
Prime mover of foot inversion
Tibial n. (L4 & L5)