Slideshow: Posterior Thigh Hamstrings

Posterior Thigh

The thigh is divided into 2 physical compartments divided by the

Medial and Lateral Intermuscular Septa

-Anterior compartment

-Posterior compartment

The Posterior Compartment of the thigh has two functionally different sets of muscles

•The Adductors

•The Hamstrings

The Adductor Muscles do not have a distinct fascial boundary, but are continuous with the muscles of the posterior compartment also known as the Hamstrings

In total the thigh is divided into 3 functional compartments

1. Anterior or Extensor compartment

1. Medial or Adductor compartment

1. Posterior or Flexor compartment

Skin

Thigh compartments

mediallateral

posterior

anterior

Cross section through right

mid-thigh looking towards hip joint

SeptaSeptaSubcutaneous Fat

Thigh compartments

mediallateral

posterior

anterior



Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior



Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior



medial intermuscular septum

lateral intermuscular septum

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior



Anterior / Extensorcompartment

Anterior Compartment

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior





Adductor Compartment

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior






Hamstring Compartment

The Hamstring Muscles of the Posterior Compartment of the Thigh


There are 3 muscles

- Biceps Femoris

- Semitendinosus

- Semimembranosus


There are 3 muscles

- Biceps Femoris

- Semitendinosus

- Semimembranosus

These muscles cross the Hip and Knee joints and coordinate extension of the Hip with flexion of the Knee

The Hamstring muscles arise from the

Ischial Tuberosity

posterior aspect

The Hamstring muscles arise from the

Ischial Tuberosity

posterior aspect

The Hamstrings lie beneath the

Gluteus Maximus muscle

There are two muscles on the medial aspect of the posterior thigh

Semimembranosus

Inserts onto the posterior aspect of the Medial Tibial

Condyle

Originates from the Superior Lateral Quadrant

of the Ischial Tuberosity

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior




Semimembranosus

Inserts onto the superior aspect

medial Tibial shaft

Semitendinosus

Originates from the Superior Lateral Quadrant

of the Ischial Tuberosity

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior




Semitendinosus

Biceps Femoris

Has two heads and lies laterally

Biceps FemorisThe Long Head originates from a combined tendon with the semimembranosus on the superior medial quadrant of the ischial tuberosity

Biceps FemorisThe Long Head originates from a combined tendon with the semimembranosus on the superior medial quadrant of the ischial tuberosity

The Short Head arises from the Femoral Shaft-middle third of the Linea Aspera-Lateral Supracondylar Ridge

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior





Adductor CompartmentBiceps Short head

Biceps Long Head

Biceps Femoris

The two muscles unite to form an aponeurosis that inserts onto

-fibular head-lateral collateral ligament of the knee-lateral tibial condyle

Femur

SeptaSepta

Thigh compartments

mediallateral

posterior

anterior



Adductor CompartmentBiceps Short head

Biceps Long Head

Semitendinosus

Semimembranosus

Nerve Supply of the Posterior Thigh

At its origin the Sciatic Nerve is the thickest

nerve in the body - 2cm

At its origin the Sciatic Nerve is the thickest

nerve in the body - 2cm

It exits the pelvis through the Greater Sciatic Foramen

and runs down the posterior aspect of the thigh

The Sciatic Nerve has two components

-Tibial Division

-Common Peroneal Division

The level at which the Sciatic nerve divides into its component parts is variable

It is usually at the middle to lower third of the thigh, but can be as high as the origin of the sciatic nerve itself

The Hamstring muscles are supplied by the

Sciatic Nerve

The Short Head of Biceps is supplied by the

Common Peroneal Division

Hamstring muscles are supplied by the

Sciatic Nerve

SemimembranosusSemitendinosus Long Head of Biceps Femoris

Are supplied by the Tibial Division

The Tibial Division of the Sciatic Nerve

also supplies the Hamstring portion of

Adductor Magnus

Summary of Muscles

SemimembranosusOrigin Superior lateral quadrant of

posterior surface ischial tuberosity

Insertion Posterior surface of the medial tibial condyle

Action Extends hip, flexes and medially rotates the knee

Nerve Supply Tibial portion of sciatic nerve (L5, S1)

Blood Supply Perforating branches of profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery

Posterior thigh

SemitendinosusOrigin Superior medial quadrant,

posterior surface ischial tuberosityInsertion Superior aspect, medial tibial shaftAction Extends hip, flexes and medially

rotates kneeNerve Supply Tibial portion sciatic nerve (L5, S1)Blood Supply Perforating branches of profunda

femoris artery, inferior gluteal artery, superior muscular branches of popliteal artery

Posterior thigh

Posterior ThighBiceps Femoris

Origin Long Head: Superior medial quadrant of the posterior surface of the ischial tuberosityShort Head: Middle third linea aspera, lateral supracondylar ridge of femur

Insertion Fibular head, with extensions to lateral collateral ligament and lateral tibial condyle

Action Flexes the knee, rotates tibia laterally, extends the hip joint

Nerve Supply Long head: tibial component of sciatic nerve, Short head: common peroneal component of sciatic nerve (L5, S1)

Blood Supply Perforating branches of profunda femoris artery, inferior gluteal artery, superior muscular branches of popliteal artery

Health & Medicine

Slideshow: Posterior Thigh Hamstrings