Lecture 16: Gait

Question 1

Describe walking gait cycle

Answer 1

Cyclic
Locomotion

Question 2

Name phases of walking gait cycle

Answer 2

Stance phase - 60% of cycle
Swing phase -40% of cycle

Question 3

Name components of stance phase

Answer 3

Double support (both feet on ground)= initial contact - Heel strike, loading response
Single support (one foot on grounf) = mild stance, terminal stance
Double support = pre swing (toe off)

Question 4

Name components of swing phase

Answer 4

All single support= initial swing (toe off), mid swing, terminal swing (heel strike)

Question 5

What is one walking gait cycle

Answer 5

From heel strike to heel strike - of the same limb
1x stance phase, 1x swing phase

Question 6

Describe grounf reaction force

Answer 6

Shifts direction and magnitude
Roughly equal to body wight
Opposite of your force
Will created unwanted forces on body- muscles oppose it

Question 7

Name the 3 msucle functions during gait

Answer 7

Propel body forwards
Supports body weight
Minimizing energy expenditure - evolutionary purpose

Question 8

Describe how lower limb muscles propel

Answer 8

Generate angular motions of limb segments
Rotation of joints = translate to linear motion

Question 9

Describe how lower limb muscles support body weight

Answer 9

Resist external forces, these produce unwanted torques at some of the lower limb joints

Question 10

Name stages of stance phase - flexion/ extension

Answer 10

Initial contact - heel strike to end of loading response
Midstance through toe off

Question 11

Name parts of heel strike to end of loading response

Answer 11

Heel strike - initial contact - double support
Loading response - foot flat - single support

Question 12

Heel strike (initial contact) and loading response (foot flat) = what is active

Answer 12

Ankle dorsiflexors
Hip extensors
Knee extensors
At very end of loading response = plantarflexors

Question 13

Heel strike (initial contact) and loading response (foot flat) = ankle dorsiflexors

Answer 13

Tibialis anterior, extensor hallucis and digitorum longus
—> prepare for heel strike
—> Control plantarflexion through loading response - so can Load foot in controlled manner

Question 14

Heel strike (initial contact) and loading response (foot flat) = hip extensors

Answer 14

Gluteus Maximus, hamstrings
—> Control hip flexion through foot flat (grf ant to hip joint, glute max contracts eccentrically)
—> Extend hip into midstance (until foot flat cause then gfr passes directly though hip joins)

Question 15

Heel strike (initial contact) and loading response (foot flat) = Knee extensors

Answer 15

Mostly vastus group
—> Extend need to prepare for heel strike (at end swing phase = prepare for heel strike)
—> Control knee flexion through midstance
(Flexor torque during foot flat phase)

Question 16

Heel strike (initial contact) and loading response (foot flat) = Plantarflexors

Answer 16

At very end of loading response
Gastrocnemius + soleus = triceps surae
—> Control dorsiflexion

Question 17

Name parts of midstance through toe off

Answer 17

Single support = midstance (grf moves along foot clockwise)
Terminal stance heel off (start push off)
Pre swing - toe off (end push off)

Question 18

Midstance, terminal stance (heel off) and preswing (toe off) = what is active

Answer 18

Plantarflexors
Intrinsic foot muscles
Just before swing phase = hip flexors, ankle dorsiflexors

Question 19

Midstance, terminal stance (heel off) and preswing (toe off) = plantarflexors

Answer 19

Triceps surae, Tibialis posterior, digital flexors, fibularis longus/brevis
—> Control dorsiflexion until heel off (then push concentrically)
—> Produce heel off and propel forward

Question 20

Midstance, terminal stance (heel off) and preswing (toe off) = Intrinsic foot msucles

Answer 20

Mostly plantar
—> Stiffen arches
Make foot right lever in preparation for heel off

Question 21

Midstance, terminal stance (heel off) and preswing (toe off) = Hip flexors

Answer 21

Rectus femoris, iliopsoas
(Start propel limb)
—> Initiate hip flexion (clear ground)

Question 22

Midstance, terminal stance (heel off) and preswing (toe off) = Ankle dorsiflexors

Answer 22

Inmate dorsiflexion (clear ground)

Question 23

Name parts of swing phase

Answer 23

Initial and mid swing
Terminal swing

Question 24

What is active during initial and mid swing and terminal swing

Answer 24

Hip flexors
Knee flexors
Ankle dorsiflexors
Hip adductors
(Flexion and extension)

Question 25

Initial and mid swing, terminal swing phase = hip flexors

Answer 25

Rectus femoris, iliopsoas —> Swing limb forward s(by flexing)

Question 26

Initial and mid swing, terminal swing phase = knee flexors

Answer 26

Hamstrings —> Flex knee to clear leg from ground —> (as hip extensors = prepare for heel strike)

Question 27

Initial and mid swing, terminal swing phase = ankle dorsiflexors

Answer 27

Dorsiflex to keep foot clear of ground (But as close as possible to ground)

Question 28

Initial and mid swing, terminal swing phase = hip adductors

Answer 28

—> Keep swing leg (right) close to stance leg —> Assist in hip flexion (bringing swing leg forwards), from hyperextended position

Question 29

What happens during stance phase

Answer 29

Hip abduction/adduction During single support phase, body mass causes a tendency of the hips to drop/tilt towards contra lateral side, recruiting hip abductors on stance leg counters this and keeps centre of mas +/- level - stance side hip abductors need to be active to control/prevent drop

Question 30

Describe msucles during stance phase hip abduction/adduction

Answer 30

Hip abductors - gluteus medius/minimus, tfl Stabilize/oppose hip adduction - pelvic tilt during single support phase

Question 31

Describe what else happens during stance phase

Answer 31

Hip rotation In transverse plane

Question 32

Describe what happens during stance phase - hip rotation

Answer 32

Early stance - hip opened Midstance To terminal stance - so close with medial rotation Stance leg hip joint rotates medially - angle between pelvis and femur decreases Assisted by gluteus medius and minimus - which are already in use to abduct hip

Question 33

Describe what happens during swing phase - hip rotation

Answer 33

Lateral rotation begins - mid swing to terminal swing So open up hip and throw leg forward Hip rotates lateral, recruits lateral hip rotators (superior/inferior gemelli, internal and external obturator, quadratus femoris, piriformis )

Question 34

Summary = gluteal region muscle functions

Answer 34

Control hip flexion - Maximus Control pelvis tilt - medius, minimus and tfl Decelerate limb

Question 35

Summary = thigh and knee region muscle functions

Answer 35

Flex knee - clear substrate and move limb forwards, prepare for heel strike (hip extensors) Flex hip to clear substrate and propel limb forwards Control knee flexion to midstance, extend knee for heel strike

Question 36

Summary = dorsiflexors of foot region muscle functions

Answer 36

Control plantarflexion - clear ground in loading response Generate dorsiflexion during swing phase (plantar flexors), - clear substrate

Question 37

Summary = leg and ankle region muscle functions

Answer 37

Control dorsiflexion through midstance, generate plantar flexion in push off (dorsiflexors)

Question 38

Summary = foot region muscle functions

Answer 38

Stiffen foot and arches Foot as level to max potential

Question 39

What are abnormal/atypical gaits

Answer 39

Deviations from kinematic patterns of normal gait cycle

Question 40

Describe why abnormal or atypical gaits

Answer 40

May be temporary - like Injury to permanent - palsy/amputation May be unilateral or bilateral May affect timing of gait cycle events and/or movements of limb segments and/or trunk Often manifests in heel strike/midstance bc strongest gfr here

Question 41

Abnormal gait - muscle weakness/paralysis - gluteus Maximus functions

Answer 41

Helps extend hip at end of swing and controls hip flexion due to ground reaction force/torque at initial contact

Question 42

Abnormal gait - muscle weakness/paralysis - gluteus Maximus gait challenge

Answer 42

Weak/paralyzed gluteus Maximus (like injury to inf gluteal nerve) - Cannot prevent/control hip flexor torque at initial contact/loading response, causing hip to buckle into flexion - on injured side

Question 43

Abnormal gait - muscle weakness/paralysis - gluteus Maximus gait compensation

Answer 43

Quickly shift the trunk posteriorly,which moves teh grf line of action posterior to the hip joint, reducing or eliminating hip flexion torque due to grf

Question 44

Abnormal gait - muscle weakness/paralysis - hip Abductors functions

Answer 44

Hip abductors control contra lateral drop of the pelvis - pelvic tilt, during single support in stance

Question 45

Abnormal gait - muscle weakness/paralysis - hip Abductors challenge

Answer 45

Weak/paralyzed gluteus medius, minimus or tfl parents smooth control of pelvis tilt = leads to Abnormal amount of drop

Question 46

Abnormal gait - muscle weakness/paralysis - hip Abductors compensation

Answer 46

Shift to the trunk over the stance leg, to reduce the torque created by the trunk during single support - throw weight over to supported side = minimize torque created by unsupported side

Question 47

Abnormal gait - muscle weakness/paralysis - hip Abductors trendelenburg gait

Answer 47

Noticeable lateral shift of trunk over the stance leg and excessive pelvic drop = indicate weakness in hip abduction

Question 48

Abnormal gait - muscle weakness/paralysis - knee extensors functions

Answer 48

Vastus group - controls knee flexion during loading response (due to grf being posterior to knee,creating a flexion torque)

Question 49

Abnormal gait - muscle weakness/paralysis - quadriceps gait challenge

Answer 49

Weak/paralyzed quadriceps - if injury or compression of femoral nerve under inguinal ligament Prevent smooth control of knee flexion during the loading response, leading to knee buckling

Question 50

Abnormal gait - muscle weakness/paralysis - quadriceps gait Compensation

Answer 50

Rapidly shift the trunk forward over the stance leg (lurch), shifting grf into extension torque and/or physically push knee to lock into extension - pop knee

Question 51

Abnormal gait - muscle weakness/paralysis - ankle dorsiflexors function

Answer 51

Control plantarflexion in the initial contact/loading response of stance AND Help clear foot/toes from ground throughout swing

Question 52

Abnormal gait - muscle weakness/paralysis - ankle dorsiflexors challenge

Answer 52

Weak/paralyzed dorsiflexors - like if injury/compression of common Fibular nerve - compartment syndrome Prevents smooth control of plantarflexion during the loading response, leading to foot slap and increased risk of tipping during swing due to drop foot

Question 53

Abnormal gait - muscle weakness/paralysis - ankle dorsiflexors compensation

Answer 53

Exaggerate knee and hip flexion in early swing phase to clear ground = stoppage gait May also shift to striking ground with midfoot or forefoot to about foot slap = equinus gait