skeletal Muscles Lower Limb Practical

Question 1

biceps femoris

Answer 1

hamstrings (on posterior of thigh)
extends thigh and flexes leg
laterally rotates leg, especially when knee is flexed

Question 2

semitendinosus

Answer 2

hamstrings (on posterior of thigh)
extends thigh and flexes leg
with semimembranosus medially rotates leg

Question 3

semimembranosus

Answer 3

hamstrings (on posterior of thigh)
extends thigh and flexes leg
medially rotates leg

Question 4

gluteus maximus

Answer 4

major extensor of thigh
complex, powerful and most effective when thigh is flexed and force is necessary, as in rising from a forward flexed position and in thrusting the thigh posteriorly in climbing stairs and running
generally inactive during standing and walking
laterally rotates and abducts thigh

Question 5

gluteus medius

Answer 5

abducts and medially rotates thigh
important for intramuscular injections
steadies pelvis
its action is extremely important in walking
muscle of limb planted on ground tilts or holds pelvis in abduction so that pelvis on side of swinging limb does not sage and foot of swinging limb can clear the ground

Question 6

rectus femoris

Answer 6

quadriceps femoris

extends leg and flexes thigh at hip

Question 7

vastus lateralis

Answer 7

intramuscular injection site particularly in infants
quadriceps femoris
extends and stabilizes leg

Question 8

vastus medialis

Answer 8

extends leg

quadriceps femoris

Question 9

sartorius

Answer 9

flexes, abducts and laterally rotates thigh
a weak knee flexor
helps produce the cross-legged position

Question 10

tibialis anterior

Answer 10

prime mover of dorsiflexion
inverts foot
helps support medial longitudinal arch of foot

Question 11

gastrocnemius

Answer 11

plantar flexes foot when leg is extended

because it crosses knee joint it can flex knee when foot is dorsiflexed

Question 12

soleus

Answer 12

plantar flexes foot
important locomotor and postural muscle during walking
running and dancing