Understanding Normal Gait: Phases and Mechanics

When observing a person's right leg during walking, does it spend more time in contact with the ground or in the air?

More contact time with the ground

What is defined as the manner of walking, running, or moving on foot?

Gait

What are repeated movements during walking called?

Gait cycles

gait cycle

The time from heel contact to heel contact of the same foot.

What percentage of the gait cycle is the stance phase?

60%.

What percentage of the gait cycle is the swing phase?

40%.

What is the stance phase in the gait cycle?

The period from heel contact to toe off, (when the foot is on the ground.)

What is the swing phase in the gait cycle?

The period from toe off to heel contact, (when the foot is in the air)

What percentage of the gait cycle is single limb support?

40%.

What percentage of the gait cycle is double limb support?

20%.

What are the two types of double limb support?

Initial double limb support and terminal double limb support.

During the L stance phase, the r limb is in

swing phase

Gait Cycle: Traditional Terminology is based on

the event or the critical action associated with each phase

What is the sequence of the stance phase in traditional terminology?

Heel contact, foot flat, midstance, heel off, and toe off.

What are the three terms used to describe the swing phase?

Early swing, mid swing, and late swing.

Ranchos los amigos periods of gait emphasizes

Emphasizes the functional task related to each phase

What are the five subphases of the stance phase in the Ranchos Los Amigos terminology?

Initial contact (IC), Loading response (LR), mid-stance (MSt), terminal stance (TSt), and pre swing (PSw).

What are the three subphases of the swing phase in the Ranchos Los Amigos terminology?

Initial swing (ISw), mid-swing (MSw), and terminal swing (TSw).

Which phases of the gait cycle are part of the single limb support period?

Single limb support occurs during the mid-stance and terminal stance phases.

What is the initial contact phase in the gait cycle?

The moment when the heel hits the floor,

Initial contact marks the

beginning of double limb support and weight acceptance.

Contralateral limb during initial contact

ending terminal stance

Loading response begins

end of ic

Loading response end

foot flat

Loading response support

double limb support

What are the objectives of the loading response phase?

To achieve weight-bearing stability, shock absorption, and continued forward progression.

contralateral limb in loading response

Pre-swing

mid stance starts at

foot flat

mid stance ends at

head, arm and trunk aligned over the stance limb

Mid stance also begins when

opposite foot lifts off the ground

What signifies the end of the midstance phase?

When the greater trochanter is vertically aligned over the midpoint of the stance foot.

What occurs during midstance in the gait cycle?

The body progresses over the stance limb, with trunk stability, beginning when the opposite foot lifts off the ground.

mid stance support

single leg

mid stance contralateral leg

mid swing

Terminal stance begins at

heel off

terminal stance ends at

IC of other limb

terminal stance aka

heel off

What is the primary objective of the terminal stance phase?

Propulsion, as the trunk advances beyond the stance limb while the limb trails behind.

Preswing

The phase from initial contact of the opposite limb to toe off of the stance leg, focusing on propulsion.

preswing aka

toe off

What happens during the initial swing phase?

The foot lifts off the floor, the knee flexes to shorten the limb, and it ends when the feet are adjacent.

Objective of preswing

position limb for swing, accelerate progression

preswing support

double

initial swing begins when

The foot is lifted off the ground

initial swing ends when

swinging foot is opposite stance foot

Objective of initial swing

foot clearance, advancement of limb from trailing position

initial swing contralateral limb

early mid-stance

Mid swing begins

feet adjacent

mid swing ends

with tibia of swing leg is vertical

What are the objectives of the mid-swing phase?

To generate forward momentum, limb shortening for foot clearance, and limb advancement.

mid-swing contralateral limb

mid-stance

Terminal swing begins

with vertical tibia of swing leg

terminal swing ends

just before initial contact

What marks the transition from swing phase back to stance phase?

The terminal swing phase

Objective of terminal swing

complete limb advancement, prepare limb for stance

when is limb advancement complete

foot moves ahead of the thigh

terminal swing contralateral limb

terminal stance

What is the significance of double limb support in the gait cycle?

It occurs during the preswing phase and involves both limbs supporting the body.

What occurs during the terminal swing phase?

The leg decelerates in preparation for ground contact, completing limb advancement.

What is the ankle position during the preswing phase?

The ankle undergoes plantar flexion (PF) between 40-60% of the gait cycle.

What is the objective of the initial swing phase?

Limb shortening for foot clearance and acceleration.

What happens to the foot during the preswing phase?

Floor contact occurs at the metatarsal heads, also known as toe off or push off.

What are spatiotemporal variables in gait?

Step length, step width, swing time, stance time, etc., describing the timing and distance aspects of gait.

What does electromyography measure during walking?

Muscle activities.

What does kinematics refer to in the context of gait?

Body movements in space.

What do kinetics involve in gait analysis?

Forces involved in generating body movements, including joint torque.

spatial gait variables

Step length, stride length, step width

step length

The distance from the heel middle point of one foot at initial contact (IC) to the heel middle point of the opposite foot.

stride length

The distance from the heel middle point IC of one foot to the heel middle point IC of the same foot.

step width

The horizontal (mediolateral) distance between the midpoints of the heels

What is the normal adult step width range?

7-10 cm.

What gait characteristic is observed in individuals with excessive abductor tone?

Narrow step width, often seen in those with Cerebral Palsy.

foot progression angle

The angle between the longitudinal axis of the foot and the line of gait progression

normal foot progression angle

5º-7º

What is cadence in gait analysis?

The number of steps taken per minute

male gait cadence

108

female gait cadence

118

Gait cadence range

100-120

step time

time from IC of one foot to IC of opposite foot

stride time

time from IC of one foot to next IC of same foot

swing time

duration a foot is in the air during gait cycle

stance time

amount of time that elapses during the stance phase of one extremity in a gait cycle

What is double support time in gait?

The duration both feet are in contact with the ground during a gait cycle

double support time occurs how many times per cycle

twice

What does gait speed measure?

The rate at which a person walks over a specific distance, measured in m/s.

female gait speed norm

1.30 m/s

Male gait speed norm

1.37 m/s

how do PTs measure gait speed

10 M walk test

6th vital sign

gait speed

Household ambulators

<0.4 m/s

limited community ambulators

0.4-0.8 m/s

community ambulators

>0.8 m/s

gait speed <0.6 m/s

strong indicator of future health care utilization and functional decline in geriatric populations

Pts with subacute stroke (60 days post stroke) who increase gait speed > 0.16 m/s are more likely to experience

a meaningful improvement in disability level than those who do not

What gait pattern occurs when there is no double limb support time?

Running.

What happens to double limb support time as walking speeds increase?

Faster walking speeds decrease double limb support time.

The transition from walking to running occurs around

4.8-5.0 MPH

2.2-2.2 M/s

What is gait symmetry?

A measure of the parallels of spatiotemporal gait variables (step length, swing time, or stance time) between the lower limbs.

How is gait symmetry calculated?

Using the ratio of right to left or the symmetry index formula: (right-left)/[0.5x(right/left)]x100.

What is the GAITRight walkway system?

A portable pressure-sensitive walkway that measures temporal and spatial parameters of gait.