The Human Gait

Question 1

What is gait?

Answer 1

Gait can be described as any method of locomotion characterised by periods
of loading and unloading the limbs
This includes:
➢ Walking
➢ Running
➢ Hopping
➢ Skipping
➢ Swimming
➢ Cycling

Question 2

What 2 phases are there of the gait cycle?

Answer 2

Stance Phase (60%)
Swing Phase (40%)

Question 3

What is the stance phase?

Answer 3

The stance phase constitutes 60% of the gait cycle.
The stance phase begins when the heel of one leg strikes the ground and end
when the toe of the same leg leaves the ground.
The stance phase can be divided into the follow events:
1. Initial contact
2. Loading response
3. Midstance
4. Terminal stance
5. Pre-swing

Question 4

What is initial contact (1)?

Answer 4

Initial contact is an instantaneous point in the time and occurs the instant the
foot of the leading lower limb strikes (makes contact with) the ground.
Initial contact represents the start of the stance phase.
Sometimes referred to as “foot strike”.
First part of the double limb support phase.

Question 5

What is the loading response (2)?

Answer 5

The loading response occupies the first 10% of the gait cycle and
occurs when initial contact is made and ends when the entire foot
is in full contact with the ground and the contralateral foot
(toe) leaves the ground.
Sometimes referred to as “initial stance”.
Second part of the double-limb support phase.
First ascending peak on a vertical force graph.

Question 6

What is midstance (3)?

Answer 6

Midstance occupies 10-30% of the gait cycle.
It begins when the contralateral foot leaves the ground and
weight is transferred onto the initial moving limb.
First part of the single limb support phase.
First descending peak on a vertical force graph.

Question 7

What is terminal stance (4)?

Answer 7

Terminal stance occupies 30-50% of the gait cycle.
It begins when the heel rises of the initial limb and finishes
when the contralateral limb strikes the ground.
Second part of the single limb support phase.
Second ascending peak on the vertical force graph.

Question 8

What is preswing (5)?

Answer 8

Preswing occupies 50-60% of the gait cycle.
Preswing begins when the contralateral foot strikes the
ground and ends when the initial limb leaves the ground
(toe-off).
Weight is transferred to the contralateral limb. This
initiates single-limb support on the contralateral limb.
Second descending peak on the vertical force graph.

Question 9

What is the swing phase?

Answer 9

The swing phase constitutes the remaining 40% of the gait cycle.
The swing phase represents the period between when the toe leaves the
ground and the heel of the same foot strikes the ground.
The swing phase can also be divided into different events:
6. Initial Swing: Limb accelerates
7. Midswing: Swinging limb overtakes the limb in stance
8. Terminal Swing: Limb decelerates

Question 10

What is initial swing (6)?

Answer 10

Initial swing constitutes ~60-75% of the gait cycle.
It begins when the foot leaves the ground and ends at
maximum knee flexion.
Single-limb support on the contralateral limb.

Question 11

What is midswing (7)?

Answer 11

Midswing occurs between 75 – 85% of the gait cycle.
Midswing begins following maximal knee flexion and
ends when the tibia is in a vertical position.
Key events include:
➢ Limb advancement
➢ Foot clearance

Question 12

What is terminal swing (8)?

Answer 12

Terminal swing forms the final phase of the gait cycle
(85 – 100%).
Key events include:
➢ The tibia transitions beyond perpendicular
➢ The knee full extends
➢ The limb decelerates (preparing for heel strike).

Question 13

What parameters can be checked in a gait analysis?

Answer 13

Support Time (single and double)
➢ Cadence
➢ Velocity
➢ Stride length/ symmetry
➢ Step length/ symmetry
➢ Muscular activity, joint angles and ground reaction forces

Question 14

How can you assess walking gait?

Answer 14

Simple Observation
➢ Frontal plane abnormalities (trunk sway, pelvic
obliquity, hip adduction/abduction/rotation)
➢ Sagittal plane abnormalities (pelvic tilt, flexion and
extension of the hip, knee and ankle)

Three dimensional analysis (Gait Laboratory)
➢ 3D motion analysis (kinematics)
➢ EMG (muscular activity)
➢ Force platform (ground reaction forces, weight
distribution)

Question 15

What is double support?

Answer 15

Both feet on the ground at the same time

Question 16

What is single support?

Answer 16

stance on one leg/ other in swing phase

Question 17

How many periods of double support are there?

Answer 17

2

Question 18

How many periods of single support are there?

Answer 18

2

Question 19

What is cadence?

Answer 19

Cadence is the number of steps (2 steps per gait cycle) a person
takes every minute.

What is the cadence of a person who takes 12 steps in 9 seconds?
Steps = 12
Time = 9 seconds
Cadence = (12 ÷ 9) × 60 = 80 steps/min

Question 20

How is step length measured?

Answer 20

Step length is measured as the distance between an initial contact of one foot
to the initial contact of the contralateral foot.

Symmetry = smallest ÷ largest

Question 21

How is stride length measured?

Answer 21

Stride length can be measured from two successive places on the same foot i.e.
two heel strikes (initial contact followed by initial contact on the same limb)

Question 22

What is gait velocity?

Answer 22

Gait velocity can be calculated from the step length and
cadence.
Gait Velocity = (step length [m] × cadence [steps/min]) ÷ 60

Question 23

What is foot angle?

Answer 23

Foot angle is measured as the angle between the line of progression and the direction of the foot during gait.

Question 24

What is the centre of pressure?

Answer 24

The centre of pressure (CoP) includes all vertical
forces being applied by the body into the ground.
1. Initial contact to the lateral side of the heel.
2. CoP transitions slightly medial to the midline
during midstance
3. During terminal stance, CoP transfers medially
of the foot mid-line
4. CoP flows through the big toe (toe-off) during
preswing.

Question 25

What are the pronation and supination phases?

Answer 25

During the walking stance phase:
➢ The foot lands supinated
➢ Quickly pronates to allow the
foot to be in full contact with
the ground (stability)
➢ Supination of the foot occurs
during terminal stance

Question 26

What are the running phases?

Answer 26

The running gait is characterised by a “float” or “ariel” phase, where both feet
are not in contact with the ground. Unlike walking, running has:
➢ Two float phases
➢ No double support phases
➢ Overlap of swing phase

Question 27

How is running gait categorised?

Answer 27

The running gait is also characterised by:
➢ Increased step length
➢ Increased stride length
➢ Increased cadence
➢ Increased gait velocity

Question 28

What are the ground reaction forces?

Answer 28

The running gait is associated with an increase in vertical ground reaction
forces.
➢ Up to ~3-5 times of body weight
➢ Forefoot or midfoot striking

Question 29

What is the base of support?

Answer 29

The running gait is associated with a reduction in the base of support.
➢ Reduced stability
➢ Increased risk of injury

Question 30

What is the Centre of Mass (CoM?)

Answer 30

An imaginary point at which all the mass can be considered
to be located is termed the Centre of Mass (CoM).
➢ The point at which the external force
of gravity will act.
➢ The centre of mass lies slightly
anterior of S2.

Question 31

What is the centre of mass (CoM) during the walking gait?

Answer 31

Vertical Displacement (sinusoidal)
➢ Rhythmic up and down movement
➢ Highest point = Midstance
➢ Lowest point = Initial contact (HS)
➢ Average displacement = 5 cm

Lateral Displacement (sinusoidal)
➢ Rhythmic side-to-side movement
➢ Lateral limit = Midstance
➢ Average displacement = 5 cm

Question 32

What are the determinations of gait?

Answer 32

Specific movements must occur to allow for a smooth and efficient pathway of gait. There are six determinants of gait (Saunder Determinants)
1. Pelvic rotation
2. Pelvic tilt
3. Knee flexion during the stance phase
4. Ankle mechanism
5. Foot mechanisms
6. Lateral displacement of the body

Question 33

What is pelvic rotation?

Answer 33

Anterior rotation of the pelvis in the
transverse plane
➢ 4° either side (8° total) during swing phase
➢ Reduces the angle of hip flexion/extension
➢ Enables a longer step-length
➢ Reduce lateral CoM displacement

Question 34

What is pelvic tilt?

Answer 34

During the swing phase, a ~5° pelvic
tilt/dip (hip adduction) occurs.
➢ This reduces the height of the Centre
of Mass during the swing phase.
➢ Presence of this “dip” during standing
is a positive Trendelenburg sign.

Question 35

What is knee flexion during the stance phase?

Answer 35

During the stance phase, a ~15°
flexion of the knee occurs.
➢ This “shortens” the leg during the
stance phase
➢ This reduces the height of the
Centre of Mass during the stance
phase.

Question 36

What is the ankle mechanism?

Answer 36

The ankle mechanism during the gait:
➢ Lengthens the leg at initial contact
➢ Reduces the need for excessive hip tilt
➢ Reducing the lowering of CoM during
initial contact.
➢ Smoothens the CoM curve

Question 37

What is the foot mechanism?

Answer 37

The foot mechanism during the gait:
➢ Increases the length of the leg (terminal
stance)
➢ This minimises the rise and fall of the hip
➢ Avoid excessive hip and knee flexion.

Question 38

What is lateral displacement of the body?

Answer 38

The centre of mass must shift over towards the
stance foot to provide balance.
➢ Facilitated by a small walking base (8 cm)
➢ Knee angled medially

Question 39

What are some gait abnormalities?

Answer 39

Antalgic Gait
➢ Ataxic Gait
➢ Hemiplegic Gait
➢ Diplegic Gait
➢ Neuropathic Gait
➢ Sensory Gait
➢ Trendelenburg Gait
➢ Myopathic Gait

Question 40

What is Antalgic gait?

Answer 40

An antalgic gait refers to a gait that occurs as
a result of pain manifestation.
➢ The patient avoids placing weight onto the
affected side.
➢ Decreased stance phase
➢ Decreased step length
➢ Decreases stride length

Question 41

What is ataxic gait?

Answer 41

An ataxic gait refers to a gait that occurs as a result of a loss of
voluntary muscle movement.
➢ Wide base
➢ Staggered line of progression (not straight)
➢ Appearance of stumbling/drunkenness
➢ Alcohol misuse, stroke, cerebral palsy, neurodegeneration

Question 42

What is Hemiplegic Gait?

Answer 42

A hemiplegic gait is characterised by:
➢ Unilateral weakness on the affected side
➢ Abnormal arm swing (arm adduction
with elbow, wrist and finger flexion)
➢ Leg circumduction (knee extension,
ankle plantarflexion and foot inversion)
➢ Common in stroke and spinal cord injury

Question 43

What is Diplegic (Scissors) Gait?

Answer 43

A diplegic gait is characterised by:
➢ Unilateral weakness on both sides (lower
is effected more than upper limb)
➢ A very narrow base
➢ Both legs are dragged along the ground
➢ Common in cerebral palsy and extreme
tightness of hip adductors

Question 44

What is Neuropathic (Steppage) Gait?

Answer 44

A neuropathic gait (steppage gait or high stepping gait) is
characterised by:
➢ Foot drop (ankle equinus) due to a loss of dorsiflexion
➢ Toes drag whilst walking
➢ Patients unable to walk on their heels.
➢ Can occur in multiple sclerosis, Parkinson’s Disease,
herniated disc, spinal fracture.

Question 45

What is Sensory Gait?

Answer 45

A sensory gait is characterised by:
➢ Loss of proprioceptive input
➢ Feet hit the floor with a high velocity
➢ Exacerbated when the feet are not visible (in the dark,
looking upwards)
➢ Occurs in disease affecting peripheral nerves

Question 46

What is Trendelenburg Gait?

Answer 46

A Trendelenburg gait is characterised
by a lateral shift of the trunk ipsilateral
to a step.
➢ For example, right step = left hip
drops and body leans right.
➢ Upper body lean acts to maintain a
central centre of mass.

Question 47

What is Myopathic Gait?

Answer 47

A myopathic gait (waddling gait) is characterised by:
➢ Bilateral Trendelenburg signs (side-to-side sway)
➢ Occurs in patients with myopathies (muscular
dystrophy)
➢ More common with old age (muscular dystrophy