The technology supporting the analysis of human motion has advanced dramatically. Past decades of locomotion research have provided us with significant knowledge about the accuracy of tests performed, the understanding of the process of human locomotion, and how clinical testing can be used to evaluate medical disorders and affect their treatment. Gait analysis is now recognized as clinically useful and financially reimbursable for some medical conditions. Yet, the routine clinical use of gait analysis has seen very limited growth. The issue of its clinical value is related to many factors, including the applicability of existing technology to addressing clinical problems; the limited use of such tests to address a wide variety of medical disorders; the manner in which gait laboratories are organized, tests are performed, and reports generated; and the clinical understanding and expectations of laboratory results. Clinical use is most hampered by the length of time and costs required for performing a study and interpreting it. A “gait” report is lengthy, its data are not well understood, and it includes a clinical interpretation, all of which do not occur with other clinical tests. Current biotechnology research is seeking to address these problems by creating techniques to capture data rapidly, accurately, and efficiently, and to interpret such data by an assortment of modeling, statistical, wave interpretation, and artificial intelligence methodologies. The success of such efforts rests on both our technical abilities and communication between engineers and clinicians.
3. INTRODUCTION :
Gait is the medical term to describe human
locomotion or the way that we walk. Thus,
it is a locomotion achieved through the
movement of limbs.
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 for
everyone.
4. PROCESS
A typical gait analysis laboratory has several cameras
(video and / or infrared) placed around a walkway or a
treadmill, which are linked to a computer. The person
has markers located at various points of reference of
the body (e.g., iliac spines of the pelvis, ankle
malleolus, and the condyles of the knee), or groups of
markers applied to half of the body segments. The
person walks down the catwalk or the treadmill and the
computer calculates the trajectory of each marker in
three dimensions.
6. GAIT CYCLE :
Gait cycle is used to describe the complex activity of walking,
by describing the motions from the period of time from one
heel strike on the ground to the next strike of the same heel,
on the ground for a second time.
8. STANCE PHASE
STANCE : Defined as the interval in
which the foot is on the ground .
It begins at the instant, that one
extremity contacts the ground &
continuous only as long as some portion
of the foot is in contact with the ground.
It is approx 60% of normal gait duration
9. SUBDIVISION OF STANCE
PHASE :
Heel strike (Initial Contact)
Foot flat (Loading Response)
Mid-stance (Mid Stance)
Heel off (Terminal Stance)
Toe off (Pre Swing)
10.
11. SWING PHASE
SWING : Defined as the interval in
which the foot is not in contact with the
ground .
It begins as soon as the toe of one
extremity leaves the ground & ceases
just before heel strike or contact of the
same extremity.
It makes up 40% of normal gait cycle
20. CONCLUSION:
Biometrics points are useful for making
identifications with camera systems, but
they depend on the existence of a
previously generated database so that
gait patterns can be compared.
1] Gait is the medical term which is used to describe locomotion of human, Locomotion is the way of walking. Gait is achieved through the movement of Limbs.
2] Evey individual has unique gait pattern but there may be some features in a person’s gait that are common for everyone. Gait patterns are distinguised through different limb movemets.
3] There are many types of gait such as walking, crawling, jogging, running and skipping.
Gait Analysis Loboratory has several cameras placed around walkway or we can say a testing spot. A person has markers located at various points on the body . When a person walks over testing spot, the computer calculates the trajectory of each marker in 3 dimensions and saves this model in the database for future use.
Temporal :- it consists the calculation of speed, length of rhythm and pitch of gait. Measurements are carried out through Stopwatch, Marks on the Ground, Pressure Mat and Laser sensors.
Kinematics:- it is basic method used for recording gait pattern of person. Single or multiple cameras can be used to make the footage .Laser sensors are used as refrence points on the body of a person which are used to measure joint angles and velocities. Infra red signal is used to collect data in this technique.
Kinetics:- it is same as kinematics but the model used for analysis is implemented in 3D rather than 2D.
Dynamic Electromyography:- it is used to study the pattern during gait analysis.
MPCA stands for Multilinear principle component analysis and it is used for data Modelling.
Gait cycle is used to describe the complex activity of walking, by describing motions from the period of time from one heel strike on the ground to the next strike of the same heel on the ground for the second time.
There are 2 phases of Walking :- Non weight phase and Weight Phase
In Non- weight phase, there is no weight on the foot.
In weight phase, there is weight on the foot.
There are two major phases of gait cycle :-
Here is a picture that shows these subdivsions of stance phase.
Heel strike phase: -
Begins with initial contact & ends with foot flat. It is beginning of the stance phase when the heel contacts the ground.
Foot flat:-
It occurs immediately following heel strike. It is the point at which the foot fully contacts the floor.
Mid stance:-
It is the point at which the body passes directly over the supporting extremity.
Heel off:-
follows mid stance and it is the point when the heel of the reference extremity leaves the ground.
Toe off:-
Is the point following heel off when only the toe of the reference extremity is in contact with the ground.
Here is the picture which shows the subdivisions of swing phase:
Acceleration phase:
It begins once the toe leaves the ground & continues until mid-swing, or the point at which the swinging extremity is directly under the body.
Mid-swing:
It occurs approx when the extremity passes directly beneath the body, or from the end of acceleration to the beginning of deceleration.
Deceleration:
It occurs after mid-swing when limb is decelerating in preparation for heel strike.
With age, the gait pattern of a person changes and doesn’t matches with the previously recorded gait pattern of that person.
Gait pattern of a person gets affected because of change in his height.
Gait pattern of a person also gets affected due to change in his size and shape of bony components.
Also due to physical injury of a person, gait pattern of that person gets affectected.
Because of these limitations, gait technology is yet to be commercialised.
Gait Analysis can be used for Authenticatioin purposes. It has a Non invasive nature and is soly dependent on external features.
Also gait technology can be used for investigation of Domestic crimes and Terrorism.
Used to identify onset of medical conditions that affect the motor capabilities of a person such as in Parkinson’s disease and multiple sclerosis where muscle control is degrading.
By placing wearable sensors on body segments, the athletes performance and the area for improvement can be analysed.
With the increasing demands of visual surveillance systems, human identification at a distance has recently gained more interest. Gait is a potential behavioral feature and many allied studies have demonstrated that it has a rich potential as a biometric for recognition. The development of computer vision techniques has also assured that vision based automatic gait analysis can be gradually achieved.
