Week 9 - The Posterior Thigh Muscles Flashcards
Which muscles make up the hamstrings?
Which compartment of the thigh do they belong to?
Biceps femoris
Semitendinosus
Semimembranous
Posterior compartment of the thigh
What is the innervation of all muscles in the posterior thigh?
(Except the short head of biceps femoris)
The tibial part of the sciatic nerve
Is semitendinosus located superficially or deep to semimembranosus?
Superficially
What are the actions of semitendinosus?
Which other muscle performs this exact set of actions?
Flexion at the knee
Extension at the hip
Medial rotation at the hip and the knee
Semimembranosus
What are the actions of semimembranosus?
Flexion at the knee
Extension at the hip
Medial rotation at the knee and hip
How many heads does biceps femoris have, and what are they called?
2 - long and short
How many tendons does biceps femoris form?
One
What is the innervation of biceps femoris?
Long head - tibial part of sciatic nerve
Short head - common fibular part of sciatic nerve
What are the actions of biceps femoris?
How does this differ from the other hamstrings?
Flexion at the knee
Extension at the hip
Lateral rotation at the hip and knee
Only difference = lateral, rather than medial, rotation
What is a “pulled hamstring”?
Excessive stretching or tearing of the fibres of the posterior thigh muscles
Who is most at risk of a pulled hamstring?
Runners and athletes in kicking sports
What happens when the muscle fibres are torn, as in a pulled hamstring injury?
Small blood vessels in the area rupture, causing haemotoma (bruising)
When a pulled hamstring occurs, a haematoma forms. Why is this bruising not visible on the skin?
The blood is contained within the fascia lata, so doesn’t reach the skin
What are the muscles of the posterior thigh also referred to as?
The hamstrings
