Fundamentals of Gait

Question 1

Why evaluate Gait?

Answer 1

• most common physical activity
• inability to walk limits participation
• disease/trauma disrupts precision, coordination, speed, and versatility [Decrease efficiency Increase energy cost]
• abnormal gait effects lower extremities
• insight to prederred movements/advanced movements

Question 2

Clinical indications for Gait Analysis

Answer 2

painful 
unstable
inability to walk quick
inability to walk efficient
inability to walk distances

Question 3

Basic functions of Locomotor Unit during gait

Answer 3

• shock absorption- impact forces
• stance stability- active or passive (frontal/sag planes)
• forward progression
• energy conversation

above pelvis is passenger (no big impact), below pelvis is locomotor!

Question 4

Passive shock absorption

Answer 4

Bones and Cartilage– non-contractile
results in hitting ground harder
ex: flat footed heavy walking

Question 5

Active shock absorption

Answer 5

Muscles–Eccentric muscle contractions
absorbs energy and is a smoother process
ex: knee ~20 degrees +/- 5 flexion
in gait eccentric contraction of quads :)

Question 6

Passive Stance Stability

Answer 6

vector aligned w/ joint centers

decreased torque (decreased lever arms)
minimum muscle activity

COM over joint centers

Question 7

Dynamic Stance Stability

Answer 7

walking is mostly dynamic
muscles are active to stabilize system

lever arms constantly changing=changing torque!

Question 8

Sagital vs. Frontal plane regarding Gait Stability

Answer 8

Frontal- unstable
Sagital- more stable

inherately good sagiatl control-> most muscles have sagital action

frontal plane relies heavily on DYNAMIC stability!!

Question 9

Forward Progression

1.Heel rocker

Answer 9

Loading response phase
Ant Tib controls
!!creates INSTABILITY and need for DYNAMIC stability!!

normal: heel first contact
pivot point- calcaneus hits, tibia rocks forward!

flat foot: no foward progression= compensations
ppl w/ balance issues- scared tendency

Question 10

Forward Progression

2.Ankle rocker

Answer 10

Midstance
Calf controls
Allows COM to translate over foot!!

!pivot point: ankle joint!
tibia moves over flat foot
action: ankle dorsiflexion

Question 11

Forward Progression

3.Forefoot/Toe Rocker

Answer 11

!Pivot point: metatarsal heads!!
!Allows COM to move over BOS!

creates a fall
heave to catch yourself-> need shock absorbers

Question 12

Forward Progression

4.Forward fall of bodyweight

Answer 12

mini fall-> creates small impact force

Question 13

Forward Progression

5.Swing limb momentum

Answer 13

other limb moves forward

Question 14

5 stages of forward progression

Answer 14

1. heel rocker
2. ankle rocker
3. forefoot/toe rocker
4. forward fall of bodyweight
5. swing limb momentum

if any are bad- lowers stability, increases energy expen

Question 15

Energy conservation of gait

Answer 15

minimizes displacement of center of mass and muscle activation

Question 16

Normal vs. abnormal gait energy conservation

Answer 16

normal: very small; unilateral, forward movement

excessive displacement: increase energy to walk

COM decreases at both feet on ground; increases single limb support
COM shifts as transition medial to lateral

Question 17

What is a phase

Answer 17

portion of given movement cycle

ex: loading response
ex: mid stance

Question 18

What is an objective

Answer 18

basic requirement of given phase

ex: shock absorption
ex: ankle rock

Question 19

What is a critical event

Answer 19

joint or segment motion or positions that are require to accomplish objective for given phase

ex: measureable angle 20 deg of knee flex
ex: 10 degree dorsiflex

Question 20

Objective of LOADING RESPONSE

Answer 20

shock absorption- (knee flexion)
forward progression- heel rocker
weight bearing stability-( hip)

Question 21

Objective of MID STANCE

Answer 21

progression of COM over BOS- ankle rocker- dorsiflexion

Single limb stance stability

Question 22

Objective of TERMINAL STANCE

Answer 22

progression of COM beyond BOS- forefoot rocker

Question 23

Objectives of PRE-SWING

Answer 23

initiate limb advancement- transition phase (hip)

Question 24

Objective of INITIAL SWING

Answer 24

limb advancement

foot clearance- trip/hitting foot happens here or mid swing

Question 25

Objective of MID-SWING

Answer 25

continued limb advancement | continued foot clearance

Question 26

Objective TERMINAL SWING

Answer 26

complete limb advancement | prepare limb for stance

Question 27

Start-finish of gait cycle is?

Answer 27

first heel contact on reference foot to the next heel strike of same foot ~1 second

Question 28

Percentage of Swing vs. Stance

Answer 28

60% stance- reference foot IN CONTACT with floor | 40% swing- reference foot NOT in contact with floor

Question 29

Three parts of STANCE w/ percentages

Answer 29

Initial double limb support- 10% BOTH on ground Single limb support- 40% ONE on ground Terminal double limb support- 10% Both on ground

Question 30

Parts of initial double limb support

Answer 30

Loading response- 10%

Question 31

Parts of single limb support

Answer 31

Mid-stance- 20% (foot flat) | Terminal stance- 20% (heel off ground)

Question 32

Parts of terminal double limb support

Answer 32

Pre-swing- 10%

Question 33

Parts of SWING w/ percentages

Answer 33

Initial: 13/3% Mid: 13.3% Terminal: 13.3%

Question 34

1. Loading Response

Answer 34

Ipsilateral (ref) INITIAL contact---->Contralateral TOE OFF refernce contact; opposite toe off

Question 35

2. Mid-stance

Answer 35

Contralateral TOE OFF---> Ref heel rise or contralat VERT TIB swing limb tib is vertical flat foot single limb support ANKLE rocker

Question 36

3. Terminal Stance

Answer 36

Ipsolat heel rise or VERT TIB on swing leg---> Contralat INITIAL contact heel off ground single limb support FOREFOOT rocker

Question 37

4. Pre-swing

Answer 37

contralat INITIAL contact---> ipsilat toe off terminal double limb support

Question 38

5. Initial swing

Answer 38

ref toe off ---> point where swing limb (ref) foot crosses stance limb foot (contralat)

Question 39

6. Mid swing

Answer 39

swing limb cross stance limb---> tibia vertical on swing limb

Question 40

7. Terminal swing

Answer 40

vertical tibia on swing---> ref foot initial contact

Question 41

Stride charachteristics

Answer 41

velocity cadence stride length ALL interrelated

Question 42

Gait velocity

Answer 42

indicates walking ability- most common outcome measure--> measure over 10 m DISTANCE/TIME avg. is 80m/min (3 mph) speed is a function of stride length and cadence

Question 43

Cadence

Answer 43

STEPS/MIN men: 108 steps/min women: 116 steps/min men less because longer stride length count heal contacts (regardless of side)

Question 44

Step vs. stride length

Answer 44

step: initial heel contact on 1 side to contact of other side stride: initial contact on one side to next contact on that SAME side (2 steps=stride) tall people have longer strides but in turn usually slower cadence if avoid heel rocker-> increase cadence and decrease stride length