this presentation contains different mechanical gait analysers , their procedure with their advantages and disadvantages. the second last slide contains references.

1. Presented by:-Dr.Jyoti Aggarwal{MPT-SPORTS}
Dr.Aditi {MPT-CARDIO}
Submitted to:- Dr. Manoj Malik

2.  INTRODUCTION
 GAIT CYCLE
 PHASES
 GAIT ANALYSIS
 METHODS OF GAIT ANALYSIS
 APPLICATIONS
 REFERENCES

3.  GAIT is the medical term to describe human
locomotion or the way that we walk.
 Different gait patterns are characterized by
differences in limb movement patterns.
Thus, every individual has a unique gait
pattern , while there are some features in a
person’s gait that are common.

4.  GAIT has been divided into a number of
segments that make it possible to describe,
understand, and analyze the events that are
occuring.
 During one gait cycle, each extremity passes
through two major phases :
 Stance phase :- when some part of the foot
is in contact with the floor, which makes up
about 60% of the gait cycle.
 Swing phase:- when the foot is not in
contact with the floor, which makes up to
the remaining 40%.

5.  EVENTS IN STANCE PHASE
1. INITIAL CONTACT(HEEL STRIKE)
2. FOOT FLAT(7%)
3. MID STANCE(30%)
4. HEEL OFF (40%)
5. TOE OFF (60%)
SUBPHASES OF STANCE PHASE
1. HEEL STRIKE PHASE(11%)
2. MID STANCE PHASE
3. PUSH OFF PHASE

6. NOTE:-PRE-SWING PHASE REFERS TO THE LAST
10% OF STANCE PHASE.
1. EARLY SWING PHASE
2. MID SWING PHASE
3. LATE SWING

8.  Gait analysis is used for two very different
purposes:
 To aid directly in the treatment of individual
patients.
 To improve our understanding of gait,
through research .

9.  VISUAL ANALYSIS
 EXAMINATION BY VEDIO RECORDER
 ELECTROGONIOMETERS
 PRESSURE BENEATH THE FOOT
 FOOTSWITCHES
 ELECTROMYOGRAPHY
 ACCELEROMETER
 GYROSCOPES
 ENERGY CONSUMPTIONS
 FORCE PLATFORMS
 KINEMATIC SYSTEM

10.  Simplest form of gait analysis . Walk min. 8m
with different speed.
 Made by unaided human eye.
 Most complicated and versatile form of analysis
despite this suffers from 4 serious limitations.
 Limitations:-
1. It is transitory giving no permanent record.
2. The eye cannot observe high speed events .
3. It is only possible to observe movements not
forces.
4. It depends entirely on the skill of individual
observer.

11. GAIT ABNORMALITY OBSERVING DIRECTION
LAT.TRUNGK BENDING SIDE
ANT.TRUNK BENDING SIDE
POS.TRUK BENDING SIDE
INC. LX LORDOSIS SIDE
CIRCUMDUCTION FRONT OR BEHIND
HIP HIKING FRONT OR BEHIND
STEPPAGE SIDE
VAULTING SIDE OR FRONT
ABNORMAL HIP ROT. FRONT OR BEHIND
EXCESSIVE KNEE EXT. SIDE
EXCESSIVE KNEE FLX. SIDE
INADEQUATE DORSIFLX CONTROL SIDE
ABNORMAL FOOT CONTACT FRONT OR BEHIND
ABNORMAL FOOT ROT. FRONT OR BEHIND
INSUFFICIENT PUSH OFF SIDE
ABNORMAL WALK BASE FRONT OR BEHIND

12.  Use of video tape and DVD or computer has
provided one of the most useful
enhancement of gait analysis.
 Thus be used to visualize events which are
too fast for unaided eye.
 It confers following advantages:-
1. It reduces no. of walks of a subject .
2. It makes it possible to show the subject
exactly how they are walking.
3. It makes it easier to teach visual gait
analysis to someone else.

13.  In it, one camera for videotaping and a separate
cassette recorder is used to replay tapes.
 Majority of camcorders are perfectly suitable
for gait analysis
 Subjects are asked to wear shorts or swim suits.
 It is important that the subject should walk as
normal as possible.
 The camera position is first adjusted to show
whole body from head to feet at the end they
turn around with a rest if nesseccary and are
recorded as they walk back again.
 The whole process is repeated .

14.  Definition: it is a device for making
continuous measurements of the angle of a
joint.
 it is mainly of two types :
1. Potentiometer
2. Flexible strain gauge
POTENTIOMETER:
a rotatory potentiometer is a variable
resistor of the type used as a radio volume
control in which turning the central spindle
produces a change in electrical resistance,
which can be measured by external circuit.

15.  It measures the angle of a joint if the body of
the potentiometer is attached to one limb
segment and the spindle to the other.
 Electrical output depends on joint position and
device can be calibrated to measure joint angle
and degrees.
 Most commonly used for knee and less commonly
for ankle and hip.
 Fixation is achieved by cuffs which wrap around
the limb above and below the joint.
 The position of potentiometer adjusted to be as
closest as joint axis.
 Trailing wires used to connect potentiometer to
the measuring equipment which is a computer.

18.  The recording of the electrical activity of
muscle tissue, or its representation as a
visual display or audible signal, using
electrodes attached to the skin or inserted
into the muscle.
 EMG can not be used to distinguish between
concentric eccentric and isometric
contractions .
 EMG is usually measured with subject
walking , as opposed to the semi static EMG.

19.  By means of
1. Surface electrodes
2. Fine wires
3. Needle electrodes

20.  Fixed to skin over the muscle, recorded as
the voltage difference b/w 2 electrodes.
 It is usually necessary also to have a
grounding electrode.
 The EMG signal picked up by surface
electrodes is the sum of the muscle action
potentials from many motor units with in the
most superficial muscle.
 Most of signals comes from with in 25mm of
the skin surface.
 Thus it is not suitable for deep muscles.

21.  EMG data may not be very specific due to
cross talk.

22.  They are introduced directly into the muscle
using a hypodermic needle which is then
withdrawn ,leaving the wire in place .
 They can be uncomfortable or even painful.
 The wire is insulated, except for few mm at the
tip.
 Signals may be recorded in 3 ways
1. Between a pair of wires inserted using a singal
needle.
2. Between 2 fine wires, inserted separately.
3. Between a single fine wire and a ground
electrode.
4. The voltage recorded with in the muscle is
generally higher than surface elecrtodes.
5. Also there is less interference from movement
and from electromagnetic.

23. 6. The signal is derived from a fairly small
region of a single muscle , generally from a
few motor units.
7. Fine wire EMG is usually performed on
selected muscle as it is an uncomfortable
and invasive technique.

24.  More appropriate to physiological research
 A hypodermic needle is used, which contains an
insulated central conductor.
 This records EMG signal from very local area with
in the muscle into which it is inserted, usually
only a single motor unit.
 Limitations of EMG:-
1. It is at best only a semi quantitative technique.
2. Gives little indication of the strength of
individual muscle.
3. It may be quite difficult to obtain satisfactory
recordings.
4. This depends partly on the skill of the operator
in selecting the recording sites and in attaching
electrodes.

25.  SPORTS
 MEDICAL
 SECURITY

26.  JOINT STRUCTURE AND FUNCTION/PAMELA
K.LEVAGIE ,CYNTHIYA C.NORKINS/ 4TH
EDITION/ GAIT.
 GAIT ANALYSIS AN INTORDUCTION/ MICHAEL
W.WHITTLE/ 4TH EDITION/ GAIT ANALYSIS.