Muscles In The Posterior Compartment Of The Thigh Flashcards
What are the muscles in the posterior compartment of the thigh called and what muscles are there?
Hamstrings
Consist of; bicep femoris, semitendinosus and semimembranosus
(Form prominent tendons medially and laterally at the back of the knee)
As a group what is the action of the hamstrings and what nerve innervates them? Include the nerve’s nerve roots.
Extend at the hip, flex at the knee
Innervated by the sciatic nerve (L4-S3)
What and where is the bicep femoris?
Most lateral muscle of the posterior thigh
It has two heads- long and short
*the common tendon of the two heads can be felt lateral at the posterior knee
What are the attachments of the biceps femoris muscle of the thigh?
Long head- originates from ischial tuberosity of pelvis.
Short head- originates from the linea aspera of the femur.
Join to form a tendon which inserts into the head of the fibula
What is the action of the bicep femoris muscle of the thigh?
Main action- flexion at the knee
Also extends the leg at the hip and laterally rotates at the hip and knee
What nerve innervates the bicep femoris muscle of the thigh?
Long head- tibial part of the sciatic nerve
Short head- common fibula part of sciatic nerve
What and where is the semitendinosus muscle of the thigh?
Posterior thigh
Largely tendinous muscles
It lies medially to the bicep femoris and covers the majority of the semimembranosus
What are the attachments of the semitendinosus muscle of the thigh?
Originates form the ischial tuberosity of the pelvis
Attaches to the medial surface of the tibia
What is the action of the semitendinosus muscle of the thigh?
Flexion of the leg at the knee joint.
Extension of thigh at the hip.
Medially rotates the thigh at hip and leg at knee
What nerve innervates the semitendinosus muscles of the thigh?
Tibial part of the sciatic nerve
What and where is the semimembranosus muscle ?
Posterior thigh
Flattered and broad
Located underneath the semitendinosus
What are the attachments of semimembranosus muscle of the thigh?
Originates from the ischial tuberosity (more superiorly than the semitendinosus and bicep femoris)
Attaches to the medial tibial condyle
What is the action of the semimembranosus muscles of the thigh?
Flexion of the leg at the knee joint.
Extension of thigh at the hip
Medially rotates the thigh at the hip joint and the leg at knee.
What nerve innervates the semimembranosus muscle of the thigh?
Tibial part of the sciatic nerve
What does damage to the hamstring muscle fibres often also include?
Rupturing of the surrounding blood vessels- producing a haematoma which is then contained by the overlying fascia lata
