Muscles Crossing Hip and Knee Muscles Crossing Hip and Knee JointsJoints

Most anterior compartment muscles of the hip Most anterior compartment muscles of the hip and thigh flex the femur at the hip and extend and thigh flex the femur at the hip and extend the leg at the kneethe leg at the knee

Posterior compartment muscles of the hip and Posterior compartment muscles of the hip and thigh extend the thigh and flex the legthigh extend the thigh and flex the leg

The medial compartment muscles all adduct the The medial compartment muscles all adduct the thighthigh

These three groups are enclosed by the fascia These three groups are enclosed by the fascia latalata

Movements of the Thigh at the Movements of the Thigh at the Hip: Hip:

Flexion and ExtensionFlexion and Extension The ball-and-socket hip joint permits flexion, The ball-and-socket hip joint permits flexion,

extension, abduction, adduction, extension, abduction, adduction, circumduction, and rotationcircumduction, and rotation

The most important thigh flexors are the The most important thigh flexors are the iliopsoas (prime mover), tensor fasciae latae, iliopsoas (prime mover), tensor fasciae latae, and rectus femorisand rectus femoris

The medially located adductor muscles and The medially located adductor muscles and sartorius assist in thigh flexionsartorius assist in thigh flexion

Movements of the Thigh at the Movements of the Thigh at the Hip: Hip:

Flexion and ExtensionFlexion and Extension Thigh extension is primarily effected by the Thigh extension is primarily effected by the

hamstring muscles (biceps femoris, hamstring muscles (biceps femoris, semitendinosus, and semimembranosus) semitendinosus, and semimembranosus)

Forceful extension is aided by the gluteus Forceful extension is aided by the gluteus maximusmaximus

Movements of the Thigh at the Hip: Movements of the Thigh at the Hip: Flexion and ExtensionFlexion and Extension

Figure 10.19a–c

Movements of the Thigh at the Movements of the Thigh at the Hip: Hip:

Other MovementsOther Movements

Abduction and rotation are effected by the Abduction and rotation are effected by the gluteus medius and gluteus minimus, and are gluteus medius and gluteus minimus, and are antagonized by the lateral rotatorsantagonized by the lateral rotators

Thigh adduction is the role of five adductor Thigh adduction is the role of five adductor muscles (adductor magnus, adductor longus, muscles (adductor magnus, adductor longus, and adductor brevis; the pectineus, and the and adductor brevis; the pectineus, and the gracilis)gracilis)

Movements of the Thigh at the Hip: Movements of the Thigh at the Hip: Other MovementsOther Movements

Figure 10.20a

Movements of the Thigh at the Movements of the Thigh at the Hip: Hip:

Other MovementsOther Movements

Figure 10.20b–c

Movements of the Knee JointMovements of the Knee Joint

The sole extensor The sole extensor of the knee is the of the knee is the quadriceps femorisquadriceps femoris

The hamstring The hamstring muscles flex the muscles flex the knee, and are knee, and are antagonists to the antagonists to the quadriceps femorisquadriceps femoris

Figure 10.19a

Fascia of the LegFascia of the Leg A deep fascia of the A deep fascia of the

leg is continuous with leg is continuous with the fascia latathe fascia lata

This fascia segregates This fascia segregates the leg into three the leg into three compartments: compartments: anterior, lateral, and anterior, lateral, and posteriorposterior

Distally, the fascia Distally, the fascia thickens and forms the thickens and forms the flexor, extensor, and flexor, extensor, and fibular retinaculaefibular retinaculae

Figure 10.22a

Muscles of the Leg: MovementsMuscles of the Leg: Movements

Various leg muscles produce the following Various leg muscles produce the following movements at the:movements at the: Ankle – dorsiflexion and plantar flexionAnkle – dorsiflexion and plantar flexion Intertarsal joints – inversion and eversion of the Intertarsal joints – inversion and eversion of the

footfoot Toes – flexion and extensionToes – flexion and extension

Muscles of the Anterior Muscles of the Anterior CompartmentCompartment

These muscles are the These muscles are the primary toe extensors primary toe extensors and ankle dorsiflexorsand ankle dorsiflexors

They include the They include the tibialis anterior, tibialis anterior, extensor digitorum extensor digitorum longus, extensor longus, extensor hallucis longus, and hallucis longus, and fibularis tertiusfibularis tertius

Figure 10.21a

Muscles of the Anterior Muscles of the Anterior CompartmentCompartment

Figure 10.21b–d

Muscles of the Lateral CompartmentMuscles of the Lateral Compartment

These muscles plantar These muscles plantar flex and evert the footflex and evert the foot

They include the They include the fibularis longus and fibularis longus and fibularis brevis fibularis brevis musclesmuscles

Figure 10.22a

Muscles of the Lateral CompartmentMuscles of the Lateral Compartment

Figure 10.22b, c

Muscles of the Posterior Muscles of the Posterior CompartmentCompartment

These muscles These muscles primarily flex the foot primarily flex the foot and the toesand the toes

They include the They include the gastrocnemius, soleus, gastrocnemius, soleus, tibialis posterior, tibialis posterior, flexor digitorum flexor digitorum longus, and flexor longus, and flexor hallucis longushallucis longus

Figure 10.23a

Muscles of the Posterior Muscles of the Posterior CompartmentCompartment

Figure 10.23b, c

Muscles of the Posterior Muscles of the Posterior CompartmentCompartment

Figure 10.23d–f

Muscle Actions of the Thigh: Muscle Actions of the Thigh: SummarySummary

Thigh muscles: Thigh muscles: Flex and extend the thigh (posterior compartment)Flex and extend the thigh (posterior compartment) Extend the leg (anterior compartment)Extend the leg (anterior compartment) Adduct the thigh (medial compartment)Adduct the thigh (medial compartment)

Muscle Actions of the Thigh: Muscle Actions of the Thigh: SummarySummary

Figure 10.24a

Muscle Actions of the Leg: Muscle Actions of the Leg: SummarySummary

Leg muscles:Leg muscles: Plantar flex and evert the foot (lateral Plantar flex and evert the foot (lateral

compartment)compartment) Plantar flex the foot and flex the toes (posterior Plantar flex the foot and flex the toes (posterior

compartment)compartment) Dorsiflex the foot and extend the toes (anterior Dorsiflex the foot and extend the toes (anterior

compartment)compartment)

Muscle Actions of the Leg: Muscle Actions of the Leg: SummarySummary

Figure 10.24b

Intrinsic Muscles of the FootIntrinsic Muscles of the Foot

These muscles help flex, extend, abduct, and These muscles help flex, extend, abduct, and adduct the toesadduct the toes

In addition, along with some leg tendons, they In addition, along with some leg tendons, they support the arch of the footsupport the arch of the foot

There is a single dorsal foot muscle, the There is a single dorsal foot muscle, the extensor digitorum brevis, which extends the extensor digitorum brevis, which extends the toestoes

The plantar muscles occur in four layersThe plantar muscles occur in four layers

Plantar Muscles: First Layer Plantar Muscles: First Layer (Superficial)(Superficial)

Superficial muscles Superficial muscles of the plantar aspect of the plantar aspect of the footof the foot

These muscles are These muscles are similar to the similar to the corresponding corresponding muscles of the handmuscles of the hand

Figure 10.25a

Plantar Muscles: Second LayerPlantar Muscles: Second Layer

Figure 10.25b

Plantar Muscles: Third LayerPlantar Muscles: Third Layer

Figure 10.25d

Plantar Muscles: Fourth LayerPlantar Muscles: Fourth Layer

Figure 10.25e–f