Anatomy- Lower Limb Muscles Flashcards
What 2 types of muscles are found in the anterior compartment of the thigh?
- Flexors of the thigh
- Extensors of the leg
Name the 3 flexors of the anterior thigh + the 2 muscles that make up the iliopsoas
-Pectineus
-Iliopsoas (psoas major + iliacus)
-Sartorius
Name the extensor muscle of the anterior thigh
Quadriceps femoris
What are all the muscles in the anterior thigh innervated by?
-All innervated by the femoral nerve L2, L3, L4
-Except psoas major anterior rami of L1, L2, L3
Name the proximal and distal attachments of the iliopsoas
PROXIMAL
-Iliacus: Iliac fossa
-Psoas major: Lumbar vertebrae
DISTAL
-Lesser trochanter of the femur
What is the action of the iliopsoas?
Flexor of the thigh at the hip joint
Name the proximal and distal attachments of the sartorius
-Proximal: ASIS
-Distal: superior, medial surface of the femur (via pes anserinus)
Name actions of sartorius
-Flexor, abductor and lateral rotation of the hip joint
-Flexor of the knee joint
What is the sartorius innervated by?
Femoral nerve
Name the group of muscles that composes the quadriceps femoRis
-Rectus femoris
-Vastus lateralis
-Vastus medialis
-Vastus intermedius
Name the proximal and distal attachments of the quadriceps femoris
PROXIMAL
-Rectus femoris: ASIS
-Vastus lateralis, vastus intermedius, vastus medius: shaft of femur
DISTAL
-Patella (via quadriceps tendon) then tibial tuberosity (via patellar tendon/ligament)
Name actions of quadriceps femoris
Extension of the knee
-Weak flexion of the hip (rectus femoris)
What is the quadriceps femoris innervated by?
Femoral nerve
What are the muscles of the medial compartment of the thigh known as? Name the muscles in the medial compartment of the thigh
Hip adductors
-Adductor magnus
-Adductor longus
-Adductor brevis
-Obturator externus
-Gracialis
What are most of the muscles of the medial compartment innervated by?
Obturator nerve (except hamstring part of adductor magnus - tibial nerve)
Where does the adductor magnus lie?
-Lies posterior to the other muscles
-Can be divided into two parts: the adductor part and the hamstring part
Name the proximal and distal attachments of the adductor magnus
PROXIMAL
Adductor part: inferior rami of pubis
Hamstring part: ischial tuberosity
DISTAL
Adductor part: linea aspera of the femur (posterior surface)
Hamstring part: adductor tubercle of the femur (posterior surface)
Name actions of adductor magnus (both, adductor, and hamstring)
-Both parts adduct the thigh
-Adductor component also flexes the thigh
-Hamstring component also extends the thigh
What innervates the adductor part and mastering part of the adductor magnus?
-Adductor part: tibial component of the sciatic nerve (L4-S3)
-Hamstring part: obturator nerve (L2-L4)
Where does the adductor longs lie?
Lies anterior to adductor magnus
Name the proximal and distal attachments of the adductor longus
Proximal: pubis
Distal: linear aspera of the femur
Name the action of the adductor longus
Adduct the thigh
What is the adductor longus innervated by?
Obturator nerve (L2-L4)
Where does the adductor brevis lie?
Lies anterior to adductor magnus and superior to adductor longus
Name the proximal and distal attachments to the adductor brevis
Proximal: body of pubis and inferior pubic rami
Distal: linear aspera of the femur
Name the actions of the adductor brevis?
Adduct the thigh
What is the adductor brevis innervated by?
Obturator nerve (L2-L4)
Name the attachments of the obturator externus
Proximal: membrane of the obturator foramen
Distal: posterior aspect of the greater trochanter
Name the action of the obturator externus
Adduction and lateral rotation of the thigh
What is the obturator externus innervated by?
Obturator nerve (L2-L4)
Where does the gracialis lie?
Most medial muscle of the group
Name the attachments of the gracialis
Proximal: inferior rami and body of pubis
Distal: medial surface of the tibia
Name the actions of the gracialis
Addution of the thigh at the hip and weak flexion of leg at knee (only muscle of this group to cross the knee joint as well as the hip joint)
What nerve innervates the gracialis?
Obturator nerve (L2-L4)
What are the muscles of the posterior compartment of the thigh known as? Name the muscles of the posterior compartment
Extensors of the thigh and flexors of the leg -
-Semitendinosus
-Semimembranosus
-Biceps femoris (short and long head)
What are the posterior thigh muscles innervated by?
-All innervated by the tibial division of sciatic nerve (L5, S1, S2)
-Except the short head of biceps femoris which is supplied by the common fibular division of the sciatic nerve
Name the proximal and distal attachments of the biceps femoris
PROXIMAL
-Long head: ischial tuberosity
-Short head: linea aspera and lateral supracondylar line of femur
DISTAL
-Both parts insert into the lateral side of the head of fibula
Tendon split at this site by the fibular collateral ligament of the knee
What are the actions of the biceps femoris?
-Flexes leg and rotates it laterally when knee is flexed
-Extends thigh
What innervates the short and long head of the biceps femoris?
- Long head: tibial division of sciatic nerve (L5, S1, S2)
-Short head: common fibular division of sciatic nerve (L5, S1, S2)
Why can’t the short head be considered a ‘true’ hamstring muscle?
-Attaches proximally to linea aspera of the femur, not to the ischial tuberosity
-Does not cross the hip joint - does not contribute to movement
-Supplied by the common fibular branch of the sciatic nerve rather than the tibial branch
Name the proximal and distal attachments of the semimembranosus
-Proximally: ischial tuberosity
-Distally: posterior part of medial condyle of tibia; reflected attachment forms oblique popliteal ligament
Name actions of the semimembranosus
-Extend thigh
-Flex leg and rotate it medially when knee is flexed
-Can extend trunk when thigh and leg are flexed
What innervates the semimembranosus?
Tibial division of sciatic nerve (L5, S1, S2)
Name the proximal and distal attachments of the semitendinosus
-Proximally: ischial tuberosity
-Distally: medial surface of superior part of tibia
Name actions of the semitendinosus
-Extend thigh
-Flex leg and rotate it medially when knee is flexed
-Can extend trunk when thigh and leg are flexed
What innervates the semitendinosus?
Tibial division of sciatic nerve (L5, S1, S2)
What general action does the superficial group of muscles do for the leg? What are they innervated by? Name the muscles contained
-Plantarflexors of ankle
- All innervated by the tibial nerve (S1, S2)
-Gastrocnemius, soleus, plantaris
Name the attachments of the gastrocnemius?
- Proximal: lateral head - lateral aspect of lateral condyle of femur, medial head - popliteal surface of femur superior to medial condyle
- Distal: posterior surface of calcaneus via calcaneal tendon (both heads)
Name the actions of the gastrocnemius
- Platarflexes ankle when knee is extended
- Raises heel during walking
- Flexes leg at knee joint
What is the gastrocnemius innervated by?
Tibial nerve (S1, S2)
Name the attachments of the soleus?
- Proximal: the head and upper part of the fibula, as well as the posterior aspect of the tibia
- Distal: posterior surface of calcaneus via calcaneal tendon
Name the actions of the soleus
- Plantarflexes ankle (independent the of the position of knee)
- Steadies leg on foot
What innervates the soleus?
Tibial nerve (S1, S2)
Describe location of plantaris in regards to gastrocnemius
Lies deep to the lateral head of gastrocnemius in approximately 90% of people
Name the attachments of the plantaris?
- Proximal: inferior end of lateral supracondylar line of femur, oblique popliteal ligament
- Distal: posterior surface of calcaneus via calcaneal tendon
Name the action of the plantaris
Weakly assists gastrocnemius in plantarflexing ankle
What innervates the plantaris?
Tibial nerve (S1, S2)