Lower Limb Mechanics

Question 1

Coxa vara vs Coxa valga

Answer 1

Vara = decreased femoral head and neck vs femur body angle (angle of inclination)

Valga = increased femoral head and neck vs femur body angle (angle of inclination)

Question 2

Q-angle

Answer 2

Angle of knee between femoral and tibial axes

• larger in female
• varum =. Smaller Q- angle
• over stretches medial meniscus and MCL
• Valgum =. Greater Q-angle
• overstretches lateral meniscus and LCL

Question 3

Patellar dislocation and genu valgum

Answer 3

Increased risk of lateral patella displacement and rupture of LCL and ACL

Question 4

Angle of Wiberg

Answer 4

Angle made between acetabulum and femoral head

Determines stability of femoral head joint

Question 5

Hip joint ligaments vs movements

Answer 5

Extension: causes anterior fibers taut and increases stability

Flexion: causes posterior fibers taut and increases mobility

Ligaments include:

• iliofemoral
• pubofemoral
• ischofemoral

Question 6

Most injuries in the hip occurs in what position?

Answer 6

Hip flexion, medial rotation and adduction

Question 7

Best joint congruence position in hips

Answer 7

Flexion, lateral rotation and abduction

Question 8

Iliofemoral ligament actions

Answer 8

Limits extension

Question 9

Pubofemoral ligament action

Answer 9

Limits hyper abduction

Question 10

Ligamentum teres purpose

Answer 10

Doesn’t really increases strength/stability but does house arteries and veins for head of femur

• tearing can cause avascular necrosis of the femoral head.

Question 11

5 extra-capsular types of ligaments in knee

Answer 11

Patellar ligament

Fibular collateral

Tibial collateral

Oblique popliteal

Arcuate popliteal

Question 12

Meniscus facts

Answer 12

Fibrocartilage disc on the articular surfaces inn the tibiafemoral joint

• shock absorber
• medial aspect more likely to be injured than lateral ( reason is directly attached to tibia)

Question 13

Malleolar mortise

Answer 13

Include medial and lateral malleoli houses the talocalcaneal joint.

Can only move plantar and dorsiflexion

• strongest during dorsiflexion
• unstable during plantarflexion
• Often sites of fractures and injuries, especially when plantarflexed

Question 14

Where is the site of amputation of the foot

Answer 14

Transverse tarsal line

Question 15

Subtalar joint

Answer 15

Below the talocrural joint (anatomical subtalar joint)

Everts and inverts the foot, however is not the only one.

Question 16

Transverse tarsal joint

Answer 16

Subtalar joint with cuboid bone

Also acts with subtalar joint to evert and invert foot.

Question 17

Pronation requires what movements?

Answer 17

Ankle dorsiflexion

Subtalar eversion

Foot abduction

Question 18

Supination requires what movements

Answer 18

Ankle plantarflexion

Subtalar inversion

Foot adduction

Question 19

Passive vs active support of the arches in feet

Answer 19

Passive = always working (autonomic)

• shapes of bones
• plantar ligaments
• spring ligament
• plantar aponeurosis

Active = dynamic support (non-autonomic)

• intrinsic foot muscles
• tendons of the foot

Question 20

Transverse arch passive and active support

Answer 20

Passive = shapes of bones

active = fibularis longus and tibialis posterior tendons

Question 21

Longitudinal arch passive and active parts

Answer 21

Passive:
- plantar and spring ligaments, plantar aponeurosis

Active:

• flexor hallucis longus
• flexor digitorum longus
• tibialis posterior and anterior
• fibularis longus

Question 22

Medial vs lateral ankle support

Answer 22

Medial (stronger)
- resists eversion and maintains longitudinal arch

Lateral (weaker)
- resists inversion