Anatomy- Hamstrings

Question 1

What are the primary function of the hamstrings?

Answer 1

Hip extension and knee flexion

Question 2

The hamstring muscles are opposing muscles to the ____ muscle group.

Answer 2

The quadriceps

Question 3

what are the 3 muscles of the hamstrings?

Answer 3

bicep femoris
semimembranosus
semitendinosus

Question 4

what is the origin & insertion of the bicep femoris ?

Answer 4

origin- ischial tuberosity
insertion - head of femur

Question 5

what is the origin & insertion of the semimembranosus ?

Answer 5

origin- ischial tuberosity
insertion - posterior of medial condyle of tibia

Question 6

what is the origin & insertion of the semitendinosus ?

Answer 6

origin- ischial tuberosity
insertion - anterior medial shaft to tibia

Question 7

what is the origin of all the hanstrings?

Answer 7

ischial tuberosity

Question 8

what actions do the hamstring group perform?

Answer 8

extend the hip (coxal joint)
flex the knee (tibiofemoral joint)
SM & ST can allow for medial rotation of tibia/knee when knee is flexed
BF can allow for lateral rotation of tibia/knee when knee is flexed

Question 9

what does the coxal joint do?

Answer 9

extend the hip

Question 10

what does the tibiofemoral joint do?

Answer 10

flex the knee

Question 11

explain the muscle direction & connection of the bicep femoris

Answer 11

inferior and lateral
it is the most lateral of the hamstrings & crosses over hip joint & crosses behind the knee

Question 12

explain the muscle direction & connection of the semimembranosus

Answer 12

inferior
crosses over the hip joint & behind the knee joint

Question 13

explain the muscle direction & connection of the semitendinosus

Answer 13

inferior
stays posterior to cross the knee then wrap anteriorly

Question 14

when a muscle crosses the knee posterior you get what movement?

Answer 14

knee flexion

Question 15

when a muscle crosses the knee anterior you get what movement?

Answer 15

knee extension

Question 16

what additional movement can the semimembranosus & semitendinosus perform ?

Answer 16

medial rotation of tibia/knee when knee is flexed

Question 17

what additional movement can the bicep femoris perform ?

Answer 17

lateral rotation of tibia/knee when knee is flexed

Question 18

how does tight hamstrings affect your posture? why can it do that?

Answer 18

bc hamstrings originate in the pelvis chronically tight hamstrings can pull the pelvis down to a posterior tilt & open the lumbar curve causing lower back tension & pain