Gait

Question 1

times of double support during gait

Answer 1

heel strike, toe off

Question 2

modifications making humans efficient walkers

Answer 2

hallux aligned with other toes + robust

arches

flexor halllucis longest (protected by seasomoid bones under 1st metatarsal + plantar ligament)

straight line of action (sustentaculum tali hollowed out calcaneus)

Question 3

modifications during stance

Answer 3

knee flexion, external rotation of pelvis

Question 4

modifications during swing

Answer 4

internal rotation of pelvis, pelvic tilt

Question 5

modifications during toe off

Answer 5

plantarflexion

Question 6

hamstrings

Answer 6

decelerate limb, stabilize knee and heel strike

Question 7

quadriceps

Answer 7

stabilize knee at heel strike

Question 8

dorsiflexors

Answer 8

lift front of foot to clear ground during swing (“high steppage”), decelerate front of foot at heel strike (“foot slap”)

Question 9

gluteus maximus

Answer 9

decelerate limb, stabilize trunk at heel strike (“trunk lurches”)

Question 10

gluteus abductors

Answer 10

prevent excess pelvic tilt (chimps lack these)

Question 11

plantarflexors

Answer 11

forward and upward thrust prior to toe off

Question 12

intrinsic foot action

Answer 12

all fire before toe-off converting foot into a rigid lever

Question 13

upper limbs

Answer 13

swing out of phase

Question 14

how running is different from walking

Answer 14

mass-spring model
energy storage in large tendons and ligaments
(plantar aponeurosis, long and short plantar ligament, plantar calcaneoavicular)