Functional Anatomy Week 3 - kinematics, knee joint and muscles

Question 1

2 types of linear motion
what do they mean

Answer 1

Rectilinear motion - all parts of an object or athlete move the same distance in the same direction at the same time
Curvilinear motion - same as rectilinear motion but over a curved path

Question 2

Angular velocity

Answer 2

The rate of change of the angular position of a rotating body

Question 3

General motion

Answer 3

A combination of linear and rotary motions

Question 4

2 main forms of biomechanical analysis

Answer 4

Kinetics - study of relationships between the forces acting on the body and how those forces affect motion
Kinematics - geometry of the motion of objects which includes displacement, velocity and acceleration

Question 5

Example of a spatial reference system

Answer 5

Cartesian coordinate system
-Joint is given a code, and tracked by cameras - used by FIFA on footballers

Question 6

Scalars and vectors

Answer 6

Scalars have a magnitude - mass, distance, speed
Vectors have a magnitude and direction - velocity, weight, acceleration

Question 7

How to calculate velocity

Answer 7

Change in displacement/change in time

Question 8

If the velocity of an object is decreasing then its acceleration is

Answer 8

Negative

Question 9

Conseravation of momentum

Answer 9

The total momentum of a system in any direction will remain constant unless an external force acts upon it

Question 10

Momentum =

Answer 10

Mass x velocity

Question 11

Impulse =

Answer 11

Force x time
Or the area under the force time graph

Question 12

Impulse represents

Answer 12

A net external force and therefore produces a change in momentum

Question 13

Impulse-momentum relationship using newtons 2nd law

Answer 13

Force = mass x acc
Acc = change in velocity/change in time
Times both sides by change in time
Force x time = mass x velocity

Question 14

Using the formula force x time = mass x velocity, any change in impulse represents a

Answer 14

Change in velocity as mass is constant

Question 15

Force, or external force, can also be represented as

Answer 15

Impact, as the external force is the impact of a body landing from a jump

Question 16

2 joints in the knee

Answer 16

Patellofemoral joint
Tibiofemoral joint

Question 17

Functions of knee joint

Answer 17

Support body weight (stability)
Transmit forces between femur and tibia (stability)
Provide movement (mobility)

Question 18

Compromise between knee stability and mobility

Answer 18

Great stability in extension and great mobility in flexion

Question 19

The tibiofemoral joint is a

Answer 19

Synovial, bicondylar joint between femoral condyles and tibial articular surfaces

Question 20

Which femoral condyle’s articular profile is longer

Answer 20

Lateral

Question 21

The ______ tibial condyle is larger and more oval shape

Answer 21

Medial

Question 22

On top of the articular surfaces are

Answer 22

Semi lunar fibrocartilage discs called menisci

Question 23

Function of menisci

Answer 23

Congruence between articular surfaces
Assist weight bearing across joints
Shock absorber

Question 24

4 major ligaments

Answer 24

Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
Medial collateral ligament (MCL)
Lateral collateral ligament (LCL)

Question 25

2 extra capsular ligaments at the knee

Answer 25

The medial and lateral collateral ligaments

Question 26

What does the medial collateral ligament prevent

Answer 26

Prevents valgus displacement --> abduction of a joint that isnt meant to abduct

Question 27

Key information about the LCL

Answer 27

Attaches onto the fibula Prevents varus displacement --> adduction of a joint that isn't meant to adduct

Question 28

2 intra capsular ligaments

Answer 28

ACL and PCL

Question 29

Anterior cruciate ligament

Answer 29

Hands in pockets ligament Prevents anterior tibial displacement (tibia moving forwards on the femur) - anterior cruciate ligament prevents anterior tibial displacement

Question 30

Posterior cruciate ligament

Answer 30

Prevents posterior tibial displacement Starts at the back

Question 31

What is the patellofemoral joint

Answer 31

Synovial saddle joint betwen articular surface of patella and patella furface of femur

Question 32

Type of bone the patella is Functions of patella

Answer 32

Largest sesamoid bone in the body Patella allows quadricep to pull the tibia around the femur and extension of the knee Reduces friction

Question 33

What happens to the patella during knee extension and flextion

Answer 33

During knee extension, patella moves proximally up the femur During flexion, the patella moves distally

Question 34

What is the joint capsule and what does it do

Answer 34

A fibrous bag of dense irregular connective tissue and holds synovial fluid in the joint

Question 35

What are bursa

Answer 35

Fluid filled sacs designed to reduce friction

Question 36

The tibiofemoral joint is a ____ joint

Answer 36

Biaxial joint Movement occurs in 2 planes around 2 axis

Question 37

Movements at the knee

Answer 37

Flexion and extension about horizontal axis in sagittal plane Medial and lateral rotation about a vertical axis in the transverse plane

Question 38

Closed pack position of the knee

Answer 38

The most stable position - extension - most contact between surfaces. No rotation possible in this position When knee goes into closed pack position --> locking mechanism

Question 39

Role of the popliteus in knee flexion

Answer 39

Unlocks the closed pack position As it contracts it laterally rotates the femur on the tibia, allowing for knee flexion. It attaches onto the meniscus and pulls the lateral meniscus backwards and stops it from getting trapped during knee flexion

Question 40

Muscles that produce medial rotation of the tibia in flexion

Answer 40

Semiteninosus, semimembranosus, gracilis and sartorius

Question 41

Muscles that produce lateral rotation of the tibia in extension

Answer 41

Long and short heads of bicep femoris

Question 42

Muscles that produce knee flexion

Answer 42

Biceps femoris, semimembranosus, semitendinosus, sartorius, gracilis, gastrocnemius (medial and lateral head)

Question 43

Muscles that produce knee extension

Answer 43

Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, tensor fascia latae

Question 44

Why does the gastrocnemius produce knee flexion

Answer 44

Both heads cross over the knee joint

Question 45

Origin and insertion of the medial and lateral head of the gastrocnemius

Answer 45

Medial condyle of femur --> Achilles tendon Lateral condyle of femur --> Achilles tendon

Question 46

Origin and insertion of semitendonosus

Answer 46

Ischium --> tibia (anteriorly)

Question 47

Origin and insertion of semimembranosus

Answer 47

Ischium --> tibia (more posteriorally)

Question 48

Origin and insertion of gracilis

Answer 48

Pubis -->medial tibia at the pes anserinus

Question 49

Origin and insertion of sartorius

Answer 49

ASIS --> medial side of tibia

Question 50

Origin and insertion of long head of biceps femoris

Answer 50

Ishcial tuberosity --> head of fibula

Question 51

Origin and insertion of short head of biceps femoris

Answer 51

Femur, attaches into same tendon as long head --> head of fibula

Question 52

Muscles that cause knee extension

Answer 52

Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, tensor fascia latae

Question 53

Origin and insertion of rectus femoris

Answer 53

ASIS --> top of patella

Question 54

Origin and insertion of vastus medialis and lateralis

Answer 54

medialis = upper part of femur, runs down linear aspera --> medial part of patella lateralis = upper part of femur, runs down linear aspera --> lateral part of patella

Question 55

Origin and insertion of vastus intermedialis

Answer 55

upper femoral shaft --> upper border of patella

Question 56

What happens to the quadracep muscles when they connect into the patella

Answer 56

All 4 hamstring muscles connect into the upper border of the patella, then the ligament goes to the tibial tuberosity