12. Lower Extremity Muscles Flashcards
Muscles of the thigh
Hip movers: psoas, iliacus, and gluteus maximus, medius, minimus
Anterior compartment: sartorius, quadriceps, and tensor fasciae latae
Medial compartment: gracilis, and adductor longus, magnus, brevis
Posterior compartment: hamstrings
OIA of psoas & iliacus
Origin:
psoas: transverse process of vertebrae
iliacus: iliac fossa of ilium
Insertion: lesser trochanter of femur (as iliopsoas)
Action: flex thigh at hip
OIA of gluteus maximus
Origin: iliac crest, sacrum
Insertion: linea aspera and iliotibial band
Action: extend thigh at hip
OIA of gluteus medius and minimus
Origin: ilium
Insertion: greater trochanter of femur
Action: abduct thigh at hip and pull center of gravity over foot when walking
OIA of Tensor fasciae latae
Origin: iliac crest
Insertion: lateral tibia via iliotibial band
Action: abduct thigh at hip, tenses IT band to stabilize hip and knee joints
OIA of sartorius
Origin: anterior superior iliac spine
Insertion: medial tibia (spans two joints)
Action: flexes and laterally rotates thigh at hip, flexes leg at knee
OIA of quadriceps
Origin:
rectus femoris: anterior inferior iliac spine
vastus muscles: linea aspera
Insertion: tibial tuberosity via patellar ligament
Action:
rectus femoris: flex thigh at hip and extend leg at knee
vastus muscles: extend leg at knee
Types of vastus muscles
Vastus lateralis, vastus intermedius, and vastus medialis
OIA of gracilis
Origin: pubis
Insertion: medial, proximal tibia
Action: adduct thigh at hip
OIA of Adductor magnus, longus, and brevis
Origin: pubis and ischium
Insertion: linea aspera
Action: adduct thigh at hip
Types of hamstrings
Semitendinosus and semimembranosus: medial side of posterior leg
Biceps femoris (long & short head): lateral side of posterior leg
OIA of hamstrings
Origin:
semitendinosus, semimembrosus, and long head of biceps femoris: ischial tuberosity
short head of biceps femoris: linea aspera
Insertion:
Semitendinosus and semimembrosus: proximal, medial tibia
biceps femoris: head of fibula
Action: extend thigh at hip, flex leg at knee
Muscles of the leg
Anterior compartment: extensors (dorsiflexors) of the foot
Lateral compartment: evertors of the foot
Posterior compartment (superficial & deep): flexors (plantar flexors) of the foot
OIA of extensors in the anterior compartment of leg
Origin: tibia & fibula
Insertion: tarsals, metatarsals, and phalanges
Action: dorsiflex and invert foot at ankle, extend toes
OIA of evertors in lateral compartment of leg
Origin: fibula
Insertion: metatarsals
Action: evert foot
Types of evertors in the leg
Fibularis longus and fibularis brevis
Tendons wrap around lateral malleolus
OIA of superficial layer of flexors in posterior compartment of leg
Origin: femoral condyle
Insertion: calcaneus (via calcaneal tendon)
Action: plantarflex foot at ankle
Type of superficial layer flexor in the leg
Gastrocnemius is the 2 headed calf muscle
OIA of deep layer flexors in posterior compartment of leg
Origin: tibia and fibula
Insertion: tarsals, metatarsals, phalanges
Action: plantarflex foot and toes, invert foot at ankle
How does inversion of the foot occur?
Both anterior no posterior compartments of the leg work together
Number of intrinsic muscles of the foot
21 muscles in total
