Gait

Question 1

Lesser gluteals

Answer 1

first half of stance
stabilize pelvis
–pull of the lesser gluteals against greater trochanter of stance leg femur prevents the hip on the stance leg side from collapsing into adduction

Question 2

Trendelenberg gait

Answer 2

damage to lesser gluteal mm
when leg on undamaged side in swing phase, pelvis and upper body drops to that side, lacking support from the lesser gluteal muscles on the opp stance leg
to compensate, laterally flex the lumbar spine towards the DAMAGED side, restoring equilibrium by making sure that they are balanced over the stance phase limb
pelvic drop at the beginning of single support followed by lateral flexion towards the other side

Question 3

Gluteus maximus

Answer 3

only active at very beginning of stance phase

prevent trunk from jack-knifing forward at moment of heel strike

Question 4

Vasti

Answer 4

first part of stance phase
prevent knee joint from collapsing into flexion as body wt is transferred onto stance phase limb
Paralysis:
kicking leg out at end of swing phase and quickly vaulting over the limb or by using their hands to apply pressure to the front of the thigh, counteracting flexion

Question 5

Hamstrings

Answer 5

active just before and just after heel strike
semitendinosus active just prior to and just after toe-off (flex knee to prepare for swing phase)
1. decelerate swinging limb in preparation for heel strike
2. aid gluteus max to prevent trunk from jack-knifing forward at heel strike
Paralysis: pt leans slightly back at heel strike to prevent jack-knifing of trunk

Question 6

Iliopsoas and adductors

Answer 6

active just prior to and just after toe-off
slow extension at hip joint at the end of stance phase and accelerate limb forward at beginning of swing phase
Paralysis: makes it impossible to bring limb forward at end of stance phase
–damage to adductors less consequential – slight tendency towards thigh abduction at beginning of swing phase

Question 7

Rectus femoris and sartorius

Answer 7

Rectus femoris: just before toe-off
Sartorius: just before toe-off and part of swing phase
Decelerate hip extension just prior to toe-off
Sartorius: flexes hip and knee to provide ground clearance
Paralysis: affect unknown

Question 8

Triceps surae

Answer 8

includes: lateral and medial heads of gastrocnemius and soleus
active during latter half of stance phase
1. eccentrically prevent excessive dorsiflexion
2. concentrically contract to provide forward momentum prior to toe-off
Paralysis:
–choppy, shuffling gait – short steps, leaning back on heels to not transfer body wt ant until the next leg has had a chance to touch down
–walk in toed out position, rolling over long axis of foot – use fibularis longus and brevis to control stability in the same way that a person w/o triceps surae paralysis would use the triceps surae

Question 9

Ant tibial muscles

Answer 9

(tibialis ant, extensor hallucis longus, extensor digitorum longus, fibularis tertius)
active dorsiflexion throughout much of gait cycle
–just prior to swing phase – ensure that toes clear obstacles and don’t touch ground
–ensure stance phase foot actually lands on the heel at heel strike and that the forefoot contacts the ground in a controlled manner, w/o much force
Paralysis: high-stepping, foot slap