WEEK 9

Question 1

what are the two main joints of the knee and describe them

Answer 1

tibiofemoral:

• between the tibia and femur
• condyloid bi axial
• flexion and extension

patellofemoral

between the patella and femur

Question 2

what are the two cruciate ligaments and what do they do

Answer 2

1) the anterior cruciate ligament which limits anterior tibial translation

2) the posterior cruciate ligaments limits posterior tibial translation

Question 3

define the roll and glide mechanism

Answer 3

the extension without gliding interferes with the congruency of the joint

• places considerable stress on the articular cartilage

Question 4

what are the mechanism for an ACL injury ( x4)

Answer 4

1) non contact injuries that occur

2) knee valgus = knee caving in and knee rotation

3) knee hyperextension

4) anterior tibial translation

Question 5

list the risk factors of the ACL injury ( x4)

Answer 5

1) previous ACL injury

2) ligament laxity ( ligaments tend to be more relaxed)

3) lower hamstring strength

4) intercondylar notch anomaly

Question 6

what are the two collateral ligaments and describe them

Answer 6

1) medial collateral ligament:

• resists knee valgus = knee abduction

2) lateral collateral ligament :

• resists knee varus
• varus= knee adduction (bending knee outwards)

Question 7

describe menisci ( x4)

Answer 7

1) adapts to shape and femoral condyles

2) shock absorption

3) prevents frictional wear

4) deforms to allow range of movement

Question 8

describe the patella (x3)

Answer 8

• increases the moment arm of the quadriceps
• if increases moment air then this produces an increase of extension torque of knee
• pallectomy reduces quadriceps strength by 20%

Question 9

describe patella tracking (x2)

Answer 9

poor tracking= lateral

• may cause anterior knee pain and chondromalacia patella

which means softening and deterioration of the patella’s cartilage

Question 10

describe the q angle

Answer 10

the line of pull of the quadriceps relative to the tibia

Question 11

what are the 2 mechanisms for a dislocated patella

Answer 11

• lower leg planted in external rotation
• patella forced laterally

Question 12

list the risk factors for a patella dislocation ( x4)

Answer 12

1- wide pelvis

2- genu valgrum

3- weak vastus medialis

4- tight lateral structures

Question 13

describe a closed chain training effect (x4)

Answer 13

1- foot is fixed

2- less co activation occurring

3- joint compression likely aids in stabilising the knees

4- benefit= less injury passed onto the ACL

Question 14

describe an open chain training effect for ACL injuries ( x3)

Answer 14

• foot is free
• knee extension generates anterior shear stress
• borne by ACL and co activated hamstrings

Question 15

describe how squatting and knee stress occur

Answer 15

squatting places load on cruciate ligaments:

1) 0-60 degrees (ACL, small loads)

2) 60-110 degrees (PCL, moderate loads)

3) loads are withstood by healthy ligaments

• compressive forces increase squat depth

Question 16

what are the 2 squat lores

Answer 16

1) keep the knee behind the plane of the toes

• spreading the load evenly

2) don’t squat below 90 degrees

• recommendations should be based on individuals needs

Question 17

what are the 3 hamstring injury mechanisms

Answer 17

1) eccentric contractions

2) high force

3) long musculoteninous length

Question 18

what are the 4 risk factors of hamstring injury

Answer 18

1) lower BFLH fascicle length

2) mixed running mechanism

3) running exposure

4) flexibility

Question 19

what are the nordic hamstring mechanisms

Answer 19

• eccentric length
• flexibility
• fascicle length