Muscle Actions of LE
Muscles of Anterior Thigh: Flexors of Hip Joint
Pectineus
Flexes and adducts thigh
assists with medial rotation of thigh
Iliopsoas
acts conjointly in flexing thigh at hip joint
The psoas major is also a postural muscle that helps control the deviation of the trunk and is active during standing
Sartorius
Flexes, abducts, and laterally rotates thigh at hip joint
flexes leg at knee joint (medially rotating leg when knee is flexed)
**The 4 actions of sartorius produce the cross-legged position aka tailors position
Muscles of the Anterior Thigh: Extensors of Knee
Quadriceps Femoris
Rectus Femoris
Extends the knee and steadies hip joint and helps iliopsoas flex thigh
Vastus Lateralis
Extends the knee
Vastus Medialis
Extends the knee
Vastus Intermedius
Extends the knee
Muscles of Medial Thigh: Adductors of Thigh
Adductor Longus
Adducts thigh
Adductor Brevis
Adducts thigh: to some extent flexes it
Adductor Magnus
Adducts thigh
Adductor part: flexes thigh
Hamstring part: extends thigh
Gracilis
Adducts thigh
flexes leg
helps rotate leg medially
Obturator Exernus
Laterally rotates thigh (ER the hip);
steadies head of femur in acetabulum
Collectively the 5 muscles listed are the adductors of the thigh, but their actions are more complex (they act as flexors of the hip joint during flexion of the knee joint and are active during walking)
Muscles of the Gluteal Region
Abductors and Rotators of Thigh
Gluteus Maximus
Extends thigh
assists in lateral rotation
Gluteus Medius
Abducts and medially rotates thigh
keeps pelvis level when ipsilateral limb is weight-bearing and advance opposite (unsupported) side during its swing phase
Gluteus Minimus
Tensor Fascia Latae
Abducts, Flexes and IR the hip
Piriformis
ER the hip
abduct flexed thigh
Obturator Internus
ER the hip
abduct flexed thigh
Superior and Inferior Gamelli
ER the hip
abduct flexed thigh
The gamelli mms blend w/ the shared tendon of the obturator internus as it attaches to the greater trochanter of the femur, collectively forming the triceps coxae
Quadratus Femoris
ER the hip
Extensors of Hip and Flexors of Knee (Hamstrings)
Biceps Femoris
flexes leg and externally rotates it when the knee is flexed
extends thigh
ex: accelerating mass during first step of gait
Semitendinosus
extends thigh
flexes leg and IR the when knee is flexed
when thigh and leg are flexed, these mm's can extend trunk
Semimembranosus