biomechanics of lower limb

Question 1

what movements can the hip perform

Answer 1

flexion and extension
abduction and adduction
internal and external rotation
circumduction

Question 2

what type of joint is the hip

Answer 2

synovial

Question 3

in which plane is the hip joint movement greatest

Answer 3

saggital (flexion / extension)

Question 4

how many degrees of flexion and extension can the hip reach on average

Answer 4

140 flexion

20 extension

Question 5

how many degrees of adduction and abduction can the hip reach on average

Answer 5

25 adduction

30 abduction

Question 6

how many degrees of internal and external rotation can the hip reach on average

Answer 6

70 internal rotation

90 external rotation

Question 7

what range of movement is required in the hip for performing common daily activities

Answer 7

at least 120 degrees of f/e

20 degrees of ab/adduction

Question 8

in bilateral stance what muscles are usually active at the hip joint

Answer 8

none

Question 9

what muscle activity is needed to stabilise the body during unilateral stance

Answer 9

abductor

Question 10

2 articulations in the knee joint

Answer 10

tibiofemoral

patellofemoral

Question 11

movement of the knee is accounted for largely by which articulation

Answer 11

tibiofemoral

Question 12

menisci are which type of cartilage

Answer 12

fibrocartilage

Question 13

what is the trochlea?

Answer 13

smooth anterior depression between the 2 femoral condoyles

Question 14

what is the intercondylar notch?

Answer 14

deep posterior depression between the 2 femoral condoyle

Question 15

what are wedged in the interocondylar notch?

Answer 15

cruciate ligaments

Question 16

name of a bone found within a tendon

Answer 16

sesamoid bone

e.g. patella

Question 17

which tendon is the patella found within

Answer 17

the quadriceps femoris muscle tendon

Question 18

why does the patella have a central ridge

Answer 18

to guide it along the groove

Question 19

what 2 things does the fibula act as an anchor for

Answer 19

biceps femoris muscle

LCL

Question 20

what causes the screw home mechanism of the knee

Answer 20

the medical condoyle is longer than the lateral (normally about 1.7 cm longer)

Question 21

when is the screw home mechanism in action

Answer 21

during the last 20 degrees of extension

Question 22

as the knee extends the tibia rotates internally or externally?

Answer 22

externally

Question 23

at what degree of flexion can the knee maximally rotate

Answer 23

90 degrees flexion

Question 24

how much flexion and extension of the knee do we need for daily activities

Answer 24

full extension

115 degrees flexion

Question 25

most important function of the patella

Answer 25

increasing the lever arm of the quadriceps femoris muscle

Question 26

as the knee flexes, does the contribution of the patella to the length of the lever arm increase or decrease?

Answer 26

decreases

Question 27

which part of the menisci has blood supply

Answer 27

outer edges

Question 28

name the 3 articulations involved in the ankle joint

Answer 28

tibiotalar fibulotalar distal tibiofibular

Question 29

what forms the medial and lateral malleoli?

Answer 29

lateral - end of fibula | medial - end of tibia

Question 30

3 most important ligaments of the ankle

Answer 30

anterior inferior talofibular ligament medial ligament lateral ligament

Question 31

what is a sprained ankle and what causes it

Answer 31

partial tear of anterior inferior talofibular ligament due o sudden adduction of the foot on a planter flexed ankle

Question 32

how many bones and synovial joints are there in the foot

Answer 32

26 bones | 57 synovial joints

Question 33

what makes up the hindfoot

Answer 33

talus and calcaneus

Question 34

what makes up the midfoot

Answer 34

cuboid, medial intermediate and lateral cuneiforms, navicular

Question 35

what makes up the forefoot

Answer 35

metatarsals and phalanges

Question 36

what is the subtalar joint the articulation between

Answer 36

talus and calcaneus

Question 37

what movement does the subtalar joint allow

Answer 37

inversion and eversion

Question 38

what arches does the foot have

Answer 38

5 longitudinal | 1 transverse

Question 39

what supports the longitudinal arches

Answer 39

plantar fascia

Question 40

attachments for plantar fasica

Answer 40

calcaneus > proximal phalanges

Question 41

what does swing through gait refer to

Answer 41

use of crutches

Question 42

what does the gait cycle start and end with

Answer 42

starts with heel contact of one foot and ends with the next heel contact of the same foot

Question 43

what is the difference between the swing phase and the stance phase

Answer 43

during the swing phase the foot is not in contact with the ground

Question 44

name the 6 phases of the gait cycle in order

Answer 44

``` heel contact flat foot mid stance heel off toe off mid swing (then heel contact again) ```

Question 45

when do peak hip flexion and extension occur

Answer 45

peak flexion - shortly after mid swing | peak extension - shortly before toe off

Question 46

on a graph of ground reaction force during walking, what will the 2 humps represent

Answer 46

1st hump - deceleration of body mass as weight is transferred onto the foot 2nd hump - foot pushing off the ground

Question 47

what type of moment is seen at the knee just after heel contact

Answer 47

theres a flexion moment as the hamstrings contract to prevent hyperextension followed by an extension moment as the quadriceps contract to prevent the knee from buckling

Question 48

what type of moment is seen at the hip just after heel contact

Answer 48

positive extension moment produced by the hip extensors to prevent the upper body falling forward

Question 49

why is hip joint force much greater during unilateral standing compared to bilateral standing

Answer 49

due to contraction of hip abductor muscles | this pulls the 2 sides of the hip joint together

Question 50

how much rotation of the knee do we need for daily activities

Answer 50

about 10 degrees

Question 51

how many degrees of flexion at the knee during gait

Answer 51

70

Question 52

range of motion at hip during gait

Answer 52

15 degrees extension | 30 degrees flexion

Question 53

rage of motion at ankle during gait

Answer 53

15 degrees plantar flexion | 10 degrees dorsi flexion

Question 54

what does the flexor carpi ulnaris do

Answer 54

flexes and adducts the wrist