Muscles of the Thigh Flashcards
Muscle compartments of the thigh
- Anterior compartment
- Medial compartment
- Posterior compartment
Anterior compartment muscles
- Sartorius
- Quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermidus)
- Articularis genu
Medial compartment of the thigh
o Gracilis o Pectineus o Adductor longus o Adductor brevis o Adductor magnus
Posterior compartment of the thigh
Hamstring muscles:
- Biceps femoris
- Semitendinosus
- Semimembranosus
Sartorius
Anterior compartment
- Longest muscle in the body
- Descends across the thigh (lateral to its medial position)
- Forms the roof of the adductor (subsartorial) canal
Sartorius origin
ASIS and notch below it
Sartorius insertion
Proximal part of medial surface of body of tibia (same as gracilis and semitendinosus) – It extends obliquely from lateral to medial across the upper thigh, then descends nearly vertically to its insertion
Sartorius nerve supply
Femoral nerve
Sartorius function
Flexes, abducts and laterally rotates at the hip
Also, flexes the knee and medially rotates the leg from flexed position
Variation in sartorius muscle
May be absent or may be split into two parts
- May have accessory sites of origin on the inguinal ligament, notch of the ilium, iliopectineal line or pubis
Quadriceps femoris group
- Four muscles of the thigh are collectively called the quadriceps femoris
- Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
- Each muscle converges at a common insertion
Quadriceps femoris origin
Unique to each individual muscle
Quadriceps femoris insertion
Entire group Tibial tuberosity via patellar ligament
- Depends on how you view the patella
- If patella is regarded as a sesamoid bone in the quadriceps tendon, then the proper tendon of insertion is the so-called patellar ligament, which continues to the tibial tuberosity
- If patella is not considered a sesamoid, the muscle can properly be thought of as inserting into the patella
- Regardless of how you see it, the primary function of the quadriceps femoris is extension of the knee, so the ultimate insertion must be the tibial tuberosity
Quadriceps femoris nerve supply
Femoral nerve
Quadriceps femoris function
- Extension of the knee
- Rectus femoris also assists in flexion of the hip
Rectus femoris origin
Two tendons
- Straight (anterior) tendon –> from AIIS
- Reflected (posterior) tendon –> from groove above acetabulum
The tendons merge to form a broad aponeurosis on the ventral surface of the muscle, so fibers of the muscle actually arise from this aponeurosis
Rectus femoris insertion
The base (superior border) of the patella, via a thick aponeurotic tendon then via the patellar ligament to the tibial tuberosity
Vastus lateralis origin
Four origins:
- Lateral lip of linea aspera
- Lateral lip of gluteal tuberosity
- Anterior and inferior borders of greater trochanter
- Proximal intertrochanteric line
Vastus lateralis insertion
Lateral border of patella and tendon of quadriceps femoris then via the patellar ligament to the tibial tuberosity
Vastus medialis origin
Five origins:
- Distal intertrochanteric line
- Medial intermuscular septum
- Tendons of adductor longus and magnus
- Proximal medial supracondylar line
- Medial lip of linea aspera
Vastus medialis insertion
Medial border of patella and tendon of quadriceps femoris then via the patellar ligament to the tibial tuberosity
Vastus intermedius origin
Proximal two thirds of the anterior and lateral surfaces of the femur
Vastus intermedius insertion
The quadriceps tendon then via the patellar ligament to the tibial tuberosity
Articularis genu origin
Anterior surface of distal femur
Articularis genu insertion
Into the synovial membrane of the knee joint
Articularis genu innervation
Femoral nerve
Articularis genu fnction
To draw the synovium proximally
Articularis genu notes
Small muscle located deep to the vastus intermedius
Articularis genu variation
May be blended with the vastus intermedius