Proximal lower limb function

Question 1

Lines of force of different quads

Answer 1

• Patella tends to track laterally
  Slightly lateral pull (parallel to femur):
• Rectus Femoris
• Vastus Intermedius
  Lateral pull:
• Vastus Lateralis
  Slightly medial pull:
• Vastus Medialis Longus
  Medial pull:
• Vastus Medialis Obliquus

Question 2

Passive insufficiency

Answer 2

• Only occurs in multi-joint muscles
• Passive insufficiency - insufficient length of a 2 joint muscle to permit full range of motion at all the joints it spans simultaneously (strain action/position)

Question 3

Active insufficiency

Answer 3

• Only occurs in multi-joint muscles
• Active insufficiency: inability for a 2-joint muscle to exert enough tension to further concentrically contract if the muscle is shortened at both joints simultaneously due too much ‘slack’ in the muscle (weak action/position)

Question 4

Hamstrings - passive + active insufficiency

Answer 4

• Active insufficiency - when the hamstrings contract to flex the knee + the hip also moves into extension, the above hamstrings cannot generate force effectively
• Passive insufficiency – when the knee is extended + the pelvis anteriorly tilts -e.g. touching the toes with the knees straight

Question 5

Quads - passive + active insufficiency

Answer 5

• Rectus femoris is the only bi-articular quadriceps
• Active insufficiency – when knee extends in hip flexion
• Passive insufficiency – when knee flexes + hip extends

Question 6

Gracilis - passive + active insufficiency

Answer 6

• Passive insufficiency – when knee is extended + the hip is in an abducted position
• Active insufficiency – when hip adducted + knee is flexing

Question 7

Sartorius - passive + active insufficiency

Answer 7

• Active insufficiency – trying to flex the knee while the hips are flexed + externally rotated
• Passive insufficiency – extending the knee with the hips extended + internally rotated