Gait analysis involves the quantitative measurement and assessment of human walking. It is used to evaluate individuals with conditions affecting mobility and to optimize athletic performance. Key aspects of gait that are measured include temporal variables like step length, stride length, cadence, and stance/swing times. Equipment used includes cameras, force plates, and electromyography to capture body and muscle movements. Gait deviations seen in neurological or musculoskeletal disorders alter temporal and spatial parameters from normal walking patterns. Gait analysis provides objective data to diagnose gait abnormalities and guide treatment.

1. Gait analysis
Dr sankirth

2. Gait: rhythmical alternating movements of the trunk & limbs
Which results in the forward progression of the centre of gravity
And the body
Gait cycle: movement of a single limb from heel strike (initial contact) to next heel
strike of same foot
Normally 1-2 sec
A single gait cycle is called stride

3. History
Earliest work on gait - BORELLI - 1682
WEBER brothers gave first clear description of gait cycle -
1836
In 1940 SCHERB studied various muscle activity during different parts
of gait cycle using treadmill & later by EMG

4. Subdivisions of gait cycle:
Stance phase : foot is in contact with ground, begins with initial
contact of heel and ends with toe off
Swing phase: foot not in contact with ground
Stance phase - 60%
Swing phase - 40%

6. Stance Swing
Heel strike Acceleration
Foot flat Mid swing
Mid stance Deceleration
Heel off
Toe off
Initial contact, loading response, mid stance, terminal stance
Pre swing, initial swing, mid swing, terminal swing

11. Gait analysis
Quantitative description of human locomotion
Study of human motion through observation augmented by
Instrumentation for measuring body movements,
body mechanics and activity of the muscles
Gait analysis is used to assess and treat individuals with conditions
affecting their ability to walk, also commonly used in sports
biomechanics to help athletes run more efficiently and to identify
posture related or movement related problems

12. Neurological control of gait
Motor cortex: voluntary modulation of gait
Cerebellum: controlling balance
Extrapyramidal tract: complex unconscious pathways
Spinal cord:reflex movements
Golgi tendon organ: proprioception
Muscle spindle: stretch reflex

13. Distance & time variables
Distance variables
Step length
Stride length
Width of walking base
Foot angle (degree of toe out or angle of gait

14. Step length
Distance between corresponding successive points of heel contact of the opposite
feet
Rt step length = lt step length in normal gait

15. Stride length:
Distance between successive points of heel contact of the same foot
Double the step length in normal gait

16. Walking base:
Side to side distance between the line of the two feet
Also known as stride width

17. Degree of toe out
Degree of toe out decreases as the speed of walking increases in
normal men

18. Time variables
Step time : referred to the amount of time spent during single step
Time between heel strike of one leg and heel strike of contralateral leg
Stride time : referred to the amount of time it takes to complete one
stride. Stride duration and gait cycle duration are the same

19. Stance time : amount of time that passes during the stance phase of
one extremity in a gait cycle. It includes single supports and
double support
Swing time : amount of time that passes during the swing phase of
one extremity in a gait cycle. If the stride time of gait cycle is one
second, stance time - 0.6 , swing time - 0.4

20. Single limb time : amount of time that passes during the period when
only one extremity is on the supporting surface in a gait cycle
Double limb time : amount of time that a person spends with both feet
on the ground during one gait cycle. The percentage of time spent
in double support decreases as the speed of walking increases

21. Cadence : number of steps per unit time
Normal 100-115 steps/min
Speed : distance covered by the body in unit time
Usually measured in m/s
Instantaneous velocity varies during the gait cycle
Average velocity (m/min) = step length (m) * cadence
Steps/min. Average walking speed = 80m/min

22. Equipments & methods
Observational : simplest form, convenient but only moderately reliable
technique
Movement measurement : Measurement systems that are aimed at
capturing the spatial trajectories of body segments usually involve a
camera system or an electromagnetic system that tracks a series of body-fixed
markers.

23. Placement of these external markers on the surface of the body
segments are aligned with particular bony landmarks
As the patient walks along a marked walkway, the cameras track and
record the marker trajectories, the planar projections of markers
viewed by each camera are used to reconstruct the three
dimensional instantaneous position of the markers relative to a
fixed laboratory coordinate
The Euler / Cardan system is the most commonly used method for
describing three-dimensional motion

24. Recently, advances have been made in the animation industry that will
have future applications in the biomechanics field. Computerised motion
analysis systems have been developed that provide marker trajectory
data in real time
Another recent development to be used for quantifying human motion is
an electromagnetic tracking system

25. limitations are the sampling frequency and the sensitivity to magnetic
interference from nearby ferromagnetic metallic structures such as
a total joint replacement.
Force Measurement
Gait analysis is also concerned with the forces that cause the
observed movement and the assessment of their effect on locomotion
Forces acting on the human body can be divided into internal and
external forces

26. The external forces - gravitational, ground reaction forces, and inertial
forces
The internal forces - transmitted by body tissues that include muscular
forces, ligament forces, and forces transmitted through joint contact.
force plates simultaneously measure the force generated by the
interaction of the foot with the ground. This resultant force is referred
to as the ground reaction force (GRF)
GRF vector is three dimensional and consists of a vertical component
plus two shear components

27. Electromyography
Electromyography (EMG) is the recording of electrical activity during
muscle contraction
provide information about the timing of muscle activity and the relative
intensity of muscle contraction. Both surface and fine-wire electrodes
have been used for gait kinesiologica EMG
Surface electrodes are convenient, easy to apply to the skin, and do
not cause irritation or discomfort to the subject. However, they pick up
signals from other active muscles in the general area of application

28. The major advantage of fine-wire electrodes is selectivity to measure
the activity of specific muscles
provide information about the timing of muscle activity and the
relative intensity of the muscle activity
Analysis of the EMG is done by a phase–time plot of the activity of
the muscle against events of the gait cycle
The muscle is considered to be activated when at least 5% of the
maximum electrical activity obtained during a manual muscle
test is present for 5% of the gait cycle.

29. Pathological gait : 4 main causes
(1) structural
(2) joint and soft tissue pathology (i.e., arthritis or ligament deficiency);
(3) myopathic disorders (i.e., muscular dystrophy); and
(4) neurologic disorders (i.e., progressive or nonprogressive
pathology of the peripheral or central nervous system
In chronic neurological impairment, gait analysis can be used to
differentiate fixed contracture, that is, static deformity, from muscular
overactivity, or, dynamic deformity

30. Limping : pt avoids weight bearing on affected side as far as possible
i.e diminished stance phase
Denotes a painful condition of affected side
Lurching : pt prolongs stance phase to improve stability
Denotes variable failure of abduction mechanism

31. Trendelenberg gait
The action of abductor in pulling downwards in stance phase become
ineffective
As a result pt lurches on affected side & pelvis drops on the
opposite side of hip
Stance phase is increased on affected side
Seen in polio, cdh, perthes, coxa vara, muscular dystrophies

32. Quadriceps gait
Weakness of quadriceps muscle the affected limb is put forward in
stepping with the body leaning toward it anteriorly
Patient gradually learns to stabilise his knee by directly transferring his
body weight over lower thigh through his ipsilateral hand
Most apparent during heel strike through the stance phase
Stance phase of affected limb increases

33. Weakness of hip flexors
Difficulty in initiating swing through
Pt externally rotates leg and uses hip adductors for swing through
Circumduction of hip exaggerates energy expenditure & produces
extreme trunk and pelvis motion
Swing phase increases

34. High stepping gait
Ankle dorsiflexors act during swing phase of cycle
Weakness of this group of muscles causes foot drop
During walking foot slap in ground on heel strike and then drops in
swing phase
To prevent this patient flexes hip and knee excessively in order to
clear the ground
Swing phase increases

36. Antalgic gait : any pathology in lower extremity which causes pain
during weight bearing result in antalgic gait
To minimise pain on weight bearing person shortens time duration of
stance phase on painful side & quickly transfers weight on normal leg
Longer stance phase on normal leg and shorter stance on painful leg

38. Hemiplegic gait : shoulder adducted elbow wrist flexed
Patient swings paralysed limb outwards & aheads in a circumduction
to avoid foot scraping ground
Seen in CVA
swing phase increases

39. Scissoring/spastic gait : spastic child with marked b/l adductor
spasm at hip & equinus in the ankle
Leg goes in to marked adduction in swing phase so that foot with
equinus goes across to opposite side
Repeated crossing of leg while walking gives scissoring appearance
Stance phase increases

41. Festinant gait : steps are short so that feet barely clear floor
If patient is pushed forward or backward compensatory flexion or
extension fails to occur & patients is forced to make a series of
propulsive or retropulsive steps with forward locomotion
Steps become successively more rapid as if trying to catch up with
centre of gravity
Seen in Parkinson’s
Swing phase decreases

43. Stamping/ataxic gait : occurs in sensory ataxia in which there is loss
of sensation in lower extremity due to disease process in peripheral
nerves , dorsal roots , dorsal column of spinal cord
Due to absence of deep position sense pt constantly observes placing
of his feet
Hip is hyperflexed & externally rotated & forefoot is dorsiflexed to
strike ground with a stamp
Stance phase increases

45. Drunkards/reeling gait : pt tends to walk irregularly on a wide base
sways from side to side with tendency of falling with each step
Seen in lesion of cerebellum , lesion connecting pathway to & from
the cerebellum
Stance phase increases

46. CROUCH GAIT: unattractive energy
expensive gait pattern followed by
anterior knee pain and patellar
pathology in adolescence
Excessive flexion at knee & hip
It is difficult to manage and usually
requires lengthening of hamstrings,
iliopsoas , rectus femoris
transfer,adequate correction of bony
problems

47. CRUTCH WALKING PATTERNS OF GAIT : 4 patterns
Swinging crutch gait - paraplegics
Four point crutch gait - unsteady pts
Two point crutch gait
Three point crutch gait
Swinging crutch gait : 2 types
Swing to crutch
Swing through crutch

48. Swing through crutch: body is swung through beyond the crutches
Fastest gait, requires functional abdominal muscles
Swing to crutch: swings body to the crutches
Four point crutch: used when all or part of body weight can be taken
on each foot
Pt is unsteady and requires a wide base of support
Rt crutch—>Lt. foot—>Lt. crutch—>rt. foot
Two point crutch: used when patient balance is good
Rt crutch & lt foot simultaneously f/by lt crutch and rt foot
simultaneously

50. Three point crutch: painful or weak
limb which cannot support whole body
weight & one lower limb which can
Both crutches support weaker lower
limb, while the stronger limb takes whole
body weight without any support from
the crutches
Both crutches & weaker lower limb
together —> stronger LL

51. https://m.youtube.com/watch?v=FFki8FtaByw

52. Thank you