The Knee

Question 1

Origin, insertion and action of Rectus Femoris

Answer 1

Origin- Anterior inferior iliac spine, Superior margin of acetabulum

Insertion- Tibial tuberosity (via patellar ligament)

Action- Hip joint: Thigh flexion; Knee joint: Leg extension

Question 2

Origin, insertion and action of Vastus Lateralis

Answer 2

Origin- Linea aspera of femur, Greater trochanter of femur

Insertion- Tibial tuberosity (via patellar ligament) (lateral condyle of femur)

Action- Knee joint: Leg extension

Question 2

Origin, insertion and action of Vastus Medialis

Answer 2

Origin- Intertrochanteric line, spiral line and linea aspera, medial supracondylar line of femur

Insertion- Tibial tuberosity (via patellar ligament) (medial condyle of femur)

Action- Knee joint: Leg extension

Question 3

Origin, insertion and action of Vasus Intermedius

Answer 3

Origin- Anterior surface of femoral shaft

Insertion- Tibial tuberosity (via patellar ligament)

Action- Knee joint: Leg extension

Question 4

Origin, insertion and action of Biceps femoris

Answer 4

Origin-
- Long head: Medial impression of ischial tuberosity
- Short head: Linea aspera of femur (lateral lip), Lateral supracondylar line of femur

Insertion- Head of fibula

Action- Hip joint: Thigh extension, Thigh external rotation; Knee joint: Leg flexion, Leg external rotation

Question 5

Origin, insertion and action of Semimembranosus

Answer 5

Origin- Medial impression of ischial tuberosity

Insertion- Medial condyle of tibia

Action- Hip joint: Thigh extension, Thigh internal rotation; Knee joint: Leg flexion, Leg internal rotation; Pelvis stabilization

Question 6

Origin, insertion and action of Semitendinosus

Answer 6

Origin- Medial impression of ischial tuberosity

Insertion- Proximal end of tibia below medial condyle of tibia (via pes anserinus)

Action- Hip joint: Thigh extension, Thigh internal rotation

-Knee joint: Leg flexion, Leg internal rotation; Pelvis stabilization

Question 7

Origin, insertion and action of Popliteus

Answer 7

Origin- Lateral condyle of femur, posterior horn of lateral meniscus of knee joint

Insertion- Posterior surface of proximal tibia

Action- Unlocks knee joint; Knee joint stabilization

Question 8

What is the classification of the knee?

Answer 8

Modified synovial hinge joint, as there is not only flexion and extension but small amounts of medial and lateral rotation.

Question 9

What is the Close Packed position for the knee?

Answer 9

Full extension with medial rotation

Question 10

Identify and explain which structures limit normal movement of knee extension.

Question 11

What is the muscle action of Popliteus

Answer 11

The Popliteus contraction acts as an unlocking mechanism when the knee is in full extension causing lateral rotation of the femur on the tibia.

Question 12

Identify and explain which other structures may be under stretch when testing the lateral collateral ligament of the knee.

Question 13

Identify and explain how shortness of rectus femoris could affect active and passive movements at both the hip and the knee.

Answer 13

Passive- Hip extension and knee flexion- passive insufficiency is when a multi joint muscles is unable to complete full range of motion in both joints which affects its longitudinal stretch.

Active-

Question 14

Identify and explain normal and abnormal findings of the anterior drawer test and how this can contribute to your reasoning

Question 15

Identify and explain the other structures that insert around the medial collateral ligament of the knee.

Answer 15

Medial collateral ligament (main stabiliser) which prevents excessive valgus stress at the knee joint. Muscles and their tendons that cross the knee joint such as Vastus medialis obliquus, pes ancerinus where the gracilis, sartorius and semitendinosus tendons attach as well as semimembranosus posteriorly.

Question 16

Identify and explain how shortness of biceps femoris could affect active and passive movements at the hip and knee

Question 16

Identify and explain the role of the vastus medialis in knee extension.

Question 17

What provides stability to the medial side of the knee?

Answer 17

Medial collateral ligament (main stabiliser) which prevents excessive valgus stress at the knee joint. Muscles and their associated tendons which cross the joint and the joint capsule such as:

• Muscles inserting onto the pes ancerinus- sartorius, gracilis,
• muscle inserting posterior to the medial epicondyle- semitendinosus and semi membanosus posteriorly

Muscles inserting anteriorly- vastus medialus obliquus.

Question 18

Identify and explain the muscles involved in medial rotation of the knee

Question 19

Identify and explain which structures limit normal movement of Knee extension

Question 20

Explain what happens during a longitudinal caudad movement of the patella in the patellofemoral joint and which range of knee movement will this help to increase?

Answer 20

The patella is gently glided towards the foot and this helps increase knee flexion

Question 21

Explain the insertion of the quadriceps tendon.

Answer 21

The quadriceps muscles all converge into the quadriceps tendon which inserts into the base of the patella. Its continuation forms the patella ligament at the apex and which inserts into the tibial tuberosity

Question 22

Explain what is meant by passive insufficiency

Answer 22

occurs when a multi-joint muscle is lengthened to its fullest extent at both joints, but also preventing the full range of motion of each joint it crosses.

Question 23

How is lateral rotation achieved actively in the knee?

Answer 23

The contraction of the popliteus muscle allows the biceps femoris to laterally rotate the knee as well as flex the knee. As does Biceps femoris with the knee flexed and slightly vastus lateralis.

Question 24

Identify and explain the stabilising features of the knee joint

Question 25

Identify and explain the end feel concept for knee flexion and how this can contribute to your reasoning

Answer 25

soft/firm capsular end feel due to the tension in the patella ligament and the quadriceps muscles. the soft tissues of the gastrocnemius and hamstrings coming into contact.

hard end feel may be due to bone on bone contact, excessive ROM may indicate laxity in the patella tendon and ligaments

Question 26

Is it possible to differentiate the contractions of the hamstrings in order to test their strength and if so how can this be done?

Answer 26

Yes, when testing hamstring strength, the tibia can be externally rotated or internally rotated whilst in knee flexion which will isolate the lateral sided biceps femoris or isolate the medial sided semimembranosus and semitendinosus

Question 27

How much medial rotation is available at the knee?

Answer 27

medial rotation of around 30-45 degrees in 90 degrees knee flexion.