Gait
Kwabena Kan–Dapaah, Ph.D.
Department of Biomedical Engineering
School of Engineering Sciences
College of Basic and Applied Sciences
University of Ghana
November 21, 2023
Outline
1
Introduction
2
Normal Gait
Terminologies
Gait Cycle Data
Energy Consumption
6th Determinants: Foot and Knee Mechanics
3
Pathological Gait
Specific Gait Abnormalities
Common Pathologies
4
Clinical Examination of Gait
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Details
At the end of this lecture, you should to be to:
define terminologies related to gait
describe the gait data
describe energy consumption of gait
describe muscle activity during gait
differentiate normal and pathological gait
References:
Introduction to Biomechanics: From Cells to Organisms, C.R. Ethier and C. A.
Simmons - Chapter 10.1 − 10.2
Saunders et al., ”The major determinants in normal and pathological gait”, J.
Bone Joint Surg Am, 1953, 35, 543-58
Lecture notes: KIN 201, 2007-1, Clinical Biomechanics of Gait, Stephen
Robinovitch, Ph.D.
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Definitions
Normal Walk or Run
A method of locomotion involving the use of two legs,
alternately, to provide both support and propulsion
Walk: at least one leg in contact with ground at all times
Normal depends on: gender, ages, body geometry
Gait
“The manner or style of walking”, rather than the walking
process itself
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
History I
Descriptive Studies
Leonardo da Vinci, Galileo and Newton
Borelli (1682) - De Motu Animalum
measured CoG of body
walking balance maintained by constant forward movement
Weber Brothers
Gait cycle - 1836
Timing of gait and pendulum-like swing of leg
Kinematics
Marey (1873)
Multiple exposure on black suit with illuminated stripes on
limbs
pressure beneath foot
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
History II
Eadweard Muybridge (1978)
24-camera triggered in suscession to capture horse
movement
extended study to naked human beings walking, running,
etc
Braune and Fischer (1895) - Der Gang des Menschen
Marey’s technique but with fluorescent strip-lights
3D trajectories, velocities and accelerations of the body
segments
Bernstein, Moscow (1930s)
Developed several photographic techniques for kinematic
measurements
studied 150 subjects
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
History III
Force platforms
Amar (1924) - described early design
Elftman (1938) - improved Amar’s design
Muscle activity
Scherb, Switzerland, (1940s)
muscle palpating during treadmill walk and EMG
Verne Inman et al. - UC at San Francisco and Berkeley
published Human Walking (Inman et al., 1981)
Mechanical analysis
Bresler & Frankel (1950)
free-body calculations for the hip, knee and ankle joints
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
History IV
their analytical techniques formed basis of many current
methods of modeling and analysis
Saunders et al. (1953) and Cavagna & Margaria (1966) Energy consumption and transfer between segments
Patricia Murray (1967)
research concentrated on variability of walking,
development of gait in children and the deterioration of gait
in old age
Mathematical modeling - Joint forces
Paul (1965)
first detailed analysis of hip joint forces (1965) and knee
(1966) during walking
Clinical application - The Ultimate Goal
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
History V
translation from lab to clinic began since 1960
in the beginning issues related to quality data
now it s how to use it beneficially
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Gait Cycle
Gait cycle - defined as the time interval between 2 successive
occurrences of one of the repetitive events of walking
Cycle time - duration of
complete cycle
stance time
swing time
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Spatiotemporal Data -
Terminologies
Gait Cycle Data
Energy Consumption
Timing of Signle/Double Support
Leading and trailing leg
Stance: 60% and Swing: 40%
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Spatiotemporal Data - Foot Placement on Ground
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Spatiotemporal Data - Cadence, Cycle Time, Speed
Cadence
The number of steps per unit time, usually given in steps per
minute
cycle time (s) = 120/cadence(steps/min)
speed (m/s) =
stride length (m) × cadence(steps/min)
120
speed (m/s) = stride length (m)/cycle time (s)
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
(1)
(2)
(3)
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinematic Data - SP Hip Angle
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinematic Data - SP Knee Angle
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinematic Data - SP Ankle
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinematic Data - FP Pelvic Obliquity
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinematic Data - TP Pelvic Rotation
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Kinetic Data - Force & CoP
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Electromyography Data - Muscle activity
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Energy Consumption
The energy used by a person who is walking can be divided
into 3 parts:
1
2
Muscles - accelerate and decelerate the trunk and limb
segments
Overheads
cardiac muscles
respiratory muscles - the diaphragm, the rib cage and the
abdominal
‘basal metabolism’
Two forms of optimization
transfers of energy
minimize displacement
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Energy Transfer
Two types of energy transfer occur during walking:
between potential and kinetic energy
up/down movements of trunk
twisting of the shoulder girdle and pelvis in opposite
directions
between one limb segment and another
Movement HAT (Head, Arms and Trunk) transfered to thigh
and shank
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Centre of Gravity (CoG)
An abstraction concept that simplifies locomotion
All forces considered to be acting at the centre of gravity (CoG)
Thus, displacement of CoG considered end result of forces and
motions concerned with locomotion
Under static conditions, CoG of the body has been determined by
Cadaver
double suspensions
Living subjects
balanced beam and volume contours
In adult fe-/males:
mid-line: about 55% from ground of the total stature1
vertebral column: anterior to 2nd sacral vertebrae
1
Crosskey et al., 1922
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Displacement
Rhythmic up-/downward displacement
of CoG
framework for examining
pathologies
High point:
25 and 75 % of cycle,
(mid-stance),
Low point:
50 % both feets on group
Functional significance:
lower displacement of CoG;
reduce energy expenditure
Inman et al., 1981
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Background
A straight line locomotion has least expenditure of energy
possible with say wheels
impossible by means of bipedal gait
Most economical alternative: low amplitude sinusoidal pathway with
gradual deflection
Newton’s second law: F = m · v · t
abrupt changes compel high energy expenditure
CoG translation through a smooth undulating pathway of low
amplitude conserves energy
body strives to achieve this
it is important to analyze the factor that determines this pathway
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
Compass Gait
A bipedal system consisting of lower extremities with no foot
Figure 1: L: Pathway series of high amplitude arcs and R: Pelvic rotation flattens arc. Source: JBdM Saunders et
al.,J. Bone Joint Surg. Am. 1953, 25:543-58
Quasi-locomotion, only flexion and extension involved
Compass: CoG rise = 10 cm, ∆P.E.∼ 70 J, Normal: CoG rise = 4 − 5
cm, ∆P.E.∼ 35 J
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
4&5th D: Human trajectory in the sagittal plane
Factors that:
raise the low point of the trajectory
1 pelvic rotation
lower the apex of the trajectory:
2 pelvic tilt
3 knee flexion during mid-stance
decrease the slope of the rise:
4 plantarflexion after heel strike
decrease the slope of the dip:
5 plantarflexion after heel-off
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Terminologies
Gait Cycle Data
Energy Consumption
6th Determinant: Lateral displacement of pelvis
Description: During stance,
the pelvis shifts laterally towards the stance limb
CoG closer to the stance leg, making it easier for the
stance-side hip abductors to raise the swing leg and control
pelvic tilt
Result:
horizontal (transverse plane) oscillation of the CoG with an
amplitude of ∼ 5 cm, and frequency one-half that of vertical
(sagittal plane) movement (∼ 1 Hz vs. 2 Hz)
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Backgorund
Normal gait occurs if locomotor system accomplishes 4 things
1
Each leg in turn must be able to support the body weight
without collapsing
2
Balance must be maintained, either statically or
dynamically, during single leg stance
3
The swinging leg must be able to advance to a position
where it can take over the supporting role
4
Sufficient power must be provided to make the necessary
limb movements and to advance the trunk.
Abnormal gait may result from
a disorder in brain, spinal cord, nerves, muscles, joints &
skeleton
presence of pain
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trendelenburg Gait
Conditions for normal (middle)
1
absence of significant pain on loading
2
adequate power in the hip abductors
3
sufficiently long lever arm for the hip abductors
4
solid & stable fulcrum in or around the hip joint.
Conditions for Trendelenburg gait
painful hip, hip abductors weakness, abnormal hip joint, wide
walking base, unequal leg length
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trendelenburg Gait
Assumptions
the weight of the trunk is 452 N
(46 kg)
the weight of the right leg is 147
N (15 kg)
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trendelenburg Gait
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trunk Bending
Figure 2: in normal walking, the line of force early in the stance phase passes behind the knee; anterior trunk
bending brings the line of force in front of the knee, to compensate for weak knee extensors.
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trunk Bending
Figure 3: in normal walking, the line of force early in the stance phase passes in front of the hip; posterior trunk
bending brings the line of force behind the hip, to compensate for weak hip extensors.
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Trunk Bending
Figure 4: when there is a fixed flexion deformity of the hip (left), the whole pelvis must rotate forwards for the femur
to move into a vertical position (right), with a resulting increase in lumbar lordosis.
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Ab. Gait Patterns: Functional Leg Discrepancy
Figure 5: The swinging leg moves in an arc, rather than straight forwards, to increase the ground clearance for the
swing foot.
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Specific Gait Abnormalities
Common Pathologies
Neurological Conditions
Cerebral palsy
Parkinsonism
Spina bifida
Stroke
Figure 6: Sagittal plane kinematic data for the left side of a 9-year-old
patient with cerebral palsy spastic diplegia
Kwabena Kan–Dapaah, Ph.D.
Figure 7: Cerebral Palsy
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Homework
During normal gait, what variation occurs in the position of
the CoG in the coronal plane?
During normal gait, what variation occurs in potential
energy of the body? How is this affected by the
determinants of gait?
What factors lower the apex of the COG during gait?
What factors raise the low point of the COG during gait?
What factors reduce the slope of the rising and falling
portions of the CoG trajectory during gait?
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics
Introduction
Normal Gait
Pathological Gait
Clinical Examination of Gait
Thank You!
Kwabena Kan–Dapaah, Ph.D.
BMEN 307: Biomechanics