Begins – heel of reference extremity contacts the supporting
Ends- heel of same reference extremity contacts the ground
1. Stance - reference extremity contact with the ground
2. Swing – reference extremity not in contact with the ground
3. Double support- 2 intervals where the weight is transferred
from one extremity to another
Approx ROM needed in normal gait and time of occurrence of
maximum flexion and extension positions for major joints
determined by joint angles.
1. Sagittal plane joint angles
2. Frontal plane joint angle
3. Transerse plane joint angles
Determinant is a various movement occurs in the body
including pelvis, knee and ankle to maintain center of
gravity of the body in a horizontal plane and ensure the
smoothing pathway of gait.
Factors responsible for minimizing the displacement of
center of gravity
DETERMINANTS OF GAIT
6" Determinants of gait:
1. Pelvic rotation.
2. Pelvic tilting.
3. Knee flexion in stance phase.
4. Foot mechanism
5. knee mechanism.
6. lateral displacement of the body.
Swinging of arms
pelvis rotates alternatively to right and to left in
relation to the line of progression in transverse
plane about the vertical axis.
magnitude : 4 degrees on either side of the central
Associated hip movement: Internal and external
rotation during stance phase.
1. Pelvic rotation
The pelvis tilts downward on swing leg (on the side
which is opposite to that of weight bearing leg) along
the frontal plane around sagittal axis.
magnitude: 5 degrees.
Associated hip movement: hip adduction in stance
phase and hip abduction in the swing phase.
2. Pelvic tilting
At initial contact, the knee is almost (0 ±5deg).
At loading response, the knee begins the first excursion of
flexion after the heel strike ( = 15deg – 20deg )
It has 3 functions:
1. Shock absorption.
2. Minimize displacement of COG.
3. Decrease energy expenditure.
3. Knee flexion in the stance phase:
At mid- stance, the extension of knee reaches (5 deg) in
At terminal stance, the knee joint reaches 0 degof extension
to start the first excursion of knee extension.
At pre-swing, the knee joint flexes up to 10deg flexion to
start the second excursion of knee flexion
Early in the stance phase:
Foot dorsiflexed ,knee extended extremity max
length COG reaches lowest point in a downward
Late in the stance phase:
Foot plantar flexed knee slight flexion maintain
COG in its beginning of progression with minimum
4. & 5. Foot and knee mechanism:
COG displaced laterally over the weight bearing
extremity twice during the cycle of motion in the
The motion is produced by the horizontal shift of pelvis
and relative adduction of hip.
Magnitude: 4.5 cm each stride
6. Lateral displacement of body and COG
1. Increase the efficiency and smoothness of pathway of
2. Decrease the vertical and lateral displacement of
centre of gravity to two inches excursion.
3. Decrease the energy expenditure.
4. Make gait more graceful.
Function of the 6 detrminants of gait
Moments produced by muscles, ligaments and bones
Are called as “flexor/ extensor “, “abductor/ adductor”,etc.
Concentric and eccentric according to the internal moment of
Walking accomplished by -
1. Bursts – concentric contraction – positive work
2. Eccentric contraction- negative work
Body saves energy by passive exchange of potential and
Initial contact – lowest potential energy
As the leg moves into midstance potential energy
rises exchange for kinetic energy
Potential energy curve drops at the same time as the
kinetic energy rises
Sum of potential and kinetic components energy
Kinetic and potential energy not matching energy
Trunk remains in erect position during normal free
speed walking on normal ground, varying only 1.5
Sagittal plane: Heel strike flexion of HAT
opposing moment provided by hip extensors
Frontal plane: COM medial to hip joint moment
balanced by hip abductor moment of the supporting
KINEMATICS AND KINETICS OF THE
Initial contact pelvis rotates counter clock wise
trunk rotates clock wise
Trunk motion prevents excess body motion and
balances rotation of the pelvis
Mediolateral translations(side to side motions):
Trunk to right-right heel strike to left toe off
Arm swinging – opposite to legs and pelvis but similar
Counter balances forward swinging of the leg and
decelerates rotation of the body
Forward swing :supscapularis, teres major and
Backward swing :middle and post deltoid, teres major
and latissimus dorsi
Forward swing medial rotators eccentrically
post deltoid eccentrically to restrain forward swing
KINEMATICS AND KINETICS OF THE
Joint Structure and Function :A Comprehensive
Analysis- Fifth Edition by Cynthia C. Norkins
Physical Rehabilitation – Fifth Edition by Susan B O’
Kinesiology The Mechanics and Pathomechanics of
Human Movement – Second Edition by Carol A. Oatis