Hip & Knee Muscle Actions Flashcards
Actions of muscles that act on the hip and knee
Gluteus Maximus (upper and lower parts)
upper part: extends, abducts and laterally rotates the hip
Lower part: extends, adducts and laterally rotates the hip
Gluteus Medius (anterior and posterior parts)
Anterior part: flex, abducts and medially rotates the hip
Posterior part: extends, abducts and laterally rotates the hip
Gluteus minimus
flexes, abducts and medially rotates the hip
Psoas Major
flexes and medially rotates the hip
* cannot ab. or ad. the hip.
Iliacus
Flexes and medially rotates the hip
* cannot ab. or ad. the hip.
Rectus Femoris
Flexes the hip
(LOP suggests hip abduction too)
Extends the knee.
- cannot medially or laterally rotate the hip.
Obturator Internus
Laterally rotates the hip
* cannot flex/ext, or ab/ad the hip.
Superior Gemellus
Laterally rotates the hip
* cannot flex/ext, or ab/ad the hip.
Inferior Gemellus
Laterally rotates the hip
* cannot flex/ext, or ab/ad the hip.
Piriformis
Abducts and laterally rotates the hip
* cannot flex/ext the hip
Obturator Externus
Adducts and laterally rotates the hip
* cannot flex/ext the hip
Quadratus Femoris
Extends, adducts and laterally rotates the hip
Pectineus
Flexes, adducts and medially (internally) rotates the hip
Adductor Magnus
True adductor part: flexes the hip.
Ex-hamstrings part: extends the hip.
All parts: Adducts and internally (medially) rotate the hip.
Adductor brevis
Adducts, flexes and internally rotates the hip
Adductor longus
Adducts, flexes and internally rotates the hip
Tensor fascia lata
Abducts, flexes and medially rotates the hip
Sartorius
Abducts, flexes and laterally rotates the hip.
Flexes and medially rotates the leg at the knee
Semimembranosus
Extends the hip and flexes the knee
Semitendinosus
Extends the hip and flexes the knee
Long head biceps femoris
Extends the hip and flexes the knee
Short head biceps femoris
Flexes the knee and laterally rotates the flexed leg
popliteus
Medially rotates the leg relative to the femur.
Unlocks the terminally locked knee at the first stage of knee flexion from full extension
Gracilis
Adducts, flexes and internally rotates the hip
Knee flexion and medial (internal) rotation around the the knee joint when its in a semiflexed position
Vastus lateralis
Extends the knee; pulls patella up and outward
Vastus Medialis
Extends the knee; pulls the patella up and inward
Vastus intermedius
Extends the knee
Articularis Genu
Contract during knee extension
Pulls the loosening knee joint capsule superiorly to prevent it from becoming impinged between the patella and the femur
