MSK - Muscles of the Posterior Compartments of the Thigh Flashcards
What are the muscles in the posterior compartment of the thigh collectively known as?
Hamstrings
What is the innvervation of the hamstrings?
The Sciatic Nerve
What is the name of the muscle highlighted in red?
How many heads does it have?
Biceps Femoris
2
Which side of the posterior knee can the short head of the Biceps Femoris be felt?
Lateral
What are the attachments of the Biceps Femoris?
Long Head - Originates from the ischial tuberosity of the pelvis
Short Head - Originates from the linea aspera on posterior surface of the femur
**Together - **The heads form a tendon, which inserts into the head of the fibula
What is the main action of the Biceps Femoris?
What else does the Biceps Femoris do?
Main - Flexion at the knee
Also extends the leg at the hip and laterally rotates the hip and the knee
What is the innervation of the Biceps Femoris?
Sciatic Nerve
What is the name of the muscle highlighted in blue?
Semitendinosus
What are the attachments of the Semitendinosus?
It originates from the ischial tuberosity of the pelvis, and attaches to the medial surface of the tibia
What are the actions of the Semitendinosus?
Flexion of the leg at the knee joint
Extension of thigh at the hip
Medially rotates the thigh at the hip join and the leg at the knee joint
What is the innervation of the Semitendinosus?
Sciatic Nerve
What is the name of the muscle highlighted in yellow?
Semimembranous
What are the attachments of the Semimembranosus?
It originates from the ischial tuberosity, but does so more superiorly than the semitendinosus and biceps femoris. It attaches to the medial tibial condyle
What are the actions of the Semimembranosus?
Flexion of the leg at the knee joint
Extension of the thigh at the hip
Medially rotates the thigh at the hip joint and the leg at the knee joint
What is the innervation of the Semimembranosus?
Sciatic Nerve
What does a hamstring strain refer to?
How are they often injured?
**Excessive stretch **or **tearing **of the muscle fibres
During sports that involve kicking or running
What is damage to the muscle fibers also likely to damage?
What would this produce?
How would it be contained?
Surrounding blood vessels
Produces a haematoma
Contained by overlyng fascia lata
How should a hamstring muscle strain be treated?
RICE Protocol
Rest
Ice
Compression
Elevation
What has happened here?
Avulsion Fracture of the Ischial Tuberosity
What is an avulsion fracture?
When a fragments of bone breaks away from the main body of bone
How does an avulsion fracture of the ischial tuberosity occur?
During what activities does an avulsion fracture usually occur?
Hamstring tendons “tear off” a piece of ischial tuberosity
During sports that require rapid contraction and relaxation of the muscles
