week 9

Question 1

Running vs Walking

Answer 1

• Increased ranges of joint motion
• Greater impact forces (2-4 x body weight in running)
• Greater eccentric muscle contraction
• Increased step length
• Reduced step width (~3cm)

Question 2

how long in running is spent in stance vs swing

Answer 2

stance - 35%
swing - 65%

Question 3

stance phase includes

Answer 3

stance

Question 4

swing phase includes

Answer 4

early float
midswing
late float

Question 5

running Loading response
Kinematics

Answer 5

• Hip flexed ~15-25°
• Knee flexed ~10-15°
• Ankle dorsiflexed 5°, followed by
  rapid plantarflexion

Question 6

running Loading response
Muscle activity

Answer 6

• Hip: lower gluteus maximus & adductor magnus peak as foot
  accepts weight (hip/pelvic stability)
• Knee: quadriceps group peaks during weight acceptance
• Ankle: tibialis posterior & peroneal muscles stabilise subtalar joint position

Question 7

running Mid-Stance
Kinematics

Answer 7

• Hip reaches peak flexion ~25-40°
• Knee reaches peak flexion ~40°
• Ankle reaches peak dorsiflexion~20°
  (tibial advancement)

Question 8

running Mid-Stance
Muscle activity

Answer 8

• Hip:
  – gluteal muscles, TFL, adductor magnus provide medial/lateral stability to hip & pelvis
  – External rotators eccentrically to control hip internal rotation
• Knee:
  – quadriceps muscles eccentrically control knee flexion & facilitate shock absorption
• Ankle:
  – gastrocnemius & soleus peak to control forward advancement of tibia
  – Tibialis posterior & peroneal muscles control normal pronation forces

Question 9

running Terminal stance
Kinematics

Answer 9

• Hip extends to 10° extension
• Knee extends to ~15°
• Ankle plantarflexes to ~30°

Question 10

running Terminal stance
Muscle activity

Answer 10

• Hip: iliacus activity increases in preparation for swing
• Knee: diminishes as advancing body serves as a knee extensor
• Ankle: diminishes, ‘push-off’ largely recoil tension in aponeurosis & tendon

Question 11

highest pressure in

Answer 11

forefoot

Question 12

peak GRF

Answer 12

mid stance

Question 13

Early float
Kinematics

Answer 13

• Hip maintains extension
• Knee begins to flex
• Ankle begins to dorsiflex

Question 14

Early float
Muscle activity

Answer 14

• Hip: iliacus & RF activity increases in preparation to flex hip
• Knee: hamstrings to flex (moderated by quadriceps
  muscles)
• Ankle: tibialis anterior to rapidly dorsiflex ankle

Question 15

Mid-swing
Kinematics

Answer 15

• Hip rapidly flexes
• Knee reaches peak flexion ~100°
• Ankle continues to dorsiflex

Question 16

mid swing
Muscle activity

Answer 16

• Hip: iliacus & rectus femoris
• Knee: hamstring muscles to flex knee towards end of mid-swing (initially passive due to hip flexion)
• Ankle: tibialis anterior to dorsiflex

Question 17

Late float
Kinematics

Answer 17

• Hip reaches peak flexion ~30-40°
• Knee extends in preparation for
  initial contact
• Ankle reaches dorsiflexion 5°

Question 18

Late float
Muscle activity

Answer 18

• Hip: iliacus & rectus femoris activity has ceased, hamstring activity increases to modulate hip flexion
• Knee: quadriceps to extend knee, hamstrings modulate knee extension
• Ankle: tibialis anterior maintains dorsiflexion

Question 19

Effect of increased running speed

Answer 19

• Increase in hip joint moments in swing
• Increase in ankle joint moments during stance
• Minimal change in knee joint moments during stance
• Hip extensors & knee flexors during terminal swing demonstrate the most dramatic increase in load

Question 20

Common running related injuries

Answer 20

• PFPS (17%)
• Achilles tendinopathy (10%)
• MTSS (8%)
• Plantar fasciitis (7%)
• ITB syndrome (6%)

Question 21

Risk factors for running injuries

Answer 21

• Overstride
• Contralateral pelvic drop
• Forward trunk lean
• Knee stiffness
• Rapid change in acute training loads

Question 22

Overstride is

Answer 22

• IC occurring “in-front of” rather than “under” body