Methods of Gait Analysis Flashcards
Clinician
visual gait analysis
videotape analysis
general gait parameters
foot placement
Clinical lab
gait timing
foot pressure distribution
EM
electrogoniometers
Research lab (HPL)
force platforms
kinematic systems
kinetic/kinematic systems
Visual Gait Analysis (pros/cons)
Type of analysis: visual identification of gait abnormalities
Advantages: costs nothing
Disadvantages: relies entirely on skill of observer, only certain gait abnormalities can be detected, does not provide objective data (visual gait analysis depends on your observational skills)
Visual gait analysis
observe from front, back, and both sides
general observation of gait: speed, fluency, symmetry
Systematic exam for positioning and movements: pelvis, spine, hips, knees, ankles, feet
Look for specific gait abnormalities: lateral trunk bending, etc
Interpret abnormal findings: primary disorder vs compensatory movements
Primary and secondary gait abnormalities
primary deficit: ex = co-spasticity of hamstrings/quads
functional consequence: stiff knee in swing (primary gait abnormality!)
compensatory mvmt = circumduction or valuting (secondary abnormality!)
The patient compensates for the stiff knee by circumducting the leg.
Co-contraction for spasticity may make it look like they are walking w/ stiff knee gait during swing. This is the primary deviation you see, but they may vault as a compensatory mvmt.
Secondary abnormalities due to primary
Videotape analysis
observational tool
type of analysis = visual analysis of videotape images
Advantages of videotape analysis
gait pattern can be viewed repeatedly
can be viewed in slow mow or stop frame
provides a permanent record
disadvantages of videotape analysis
not an objective measurement
only records certain gait abnormalities
General gait parameters
type of analysis = measurement of cadence, stride length, and velocity
advantages of general gait parameters
quantifies general ability to walk
gives objective data
inexpensive
follows progress over time
disadvantages of general gait parameters
information is nonspecific b/c deviations can come from many pathologies
Foot placement
type of analysis = measurement of foot placement on ground
advantages of foot placement
gives walking base, step and stride lengths
gives toe-out angle and foot contact pattern
inexpensive
disadvantages of foot placement
limited information
may be messy and time-consuming
Johannes Kepler
famous astronomer
until you measure something you don’t know much about it
fundamental concept for evidence based practice
Instrumented gait analysis
motion measurement systems (where kinematics/observation fall short)
muscle activation measurement
force measurement - GRF
timing measurement
pressure measurement
ambulatory systems (force/balance measurement)
Gait timing
type of analysis = electronic measurement of foot contact timing (tells you when a step started and when it finished)
advantages of gait timing
gives stance, swing, and double-support time
gives cadence and speed
may also give foot flat and heel rise timing
disadvantages of gait timing
gives limited info
may be expensive
Gait timing
has foot switches that time foot contact
electric systems that gives you timing of foot contact during gait
Foot pressure distribution
type of analysis = maps pressure beneath sole of foot
pressure map under foot
pressure = force/area
Advantages of foot pressure distribution
detects dangerous pressure before ulcer formation
permits pressure reliving insoles to be tested
can hep determine orthotics needed for dibetic or non diabetic
disadvantages of foot pressure distribution
useful only in certain patient groups
expensive
EMG
measurement of electrical activity of muscles
advantages of EMG
detects underlying causes of gait abnormalities (cocontraction)
essential prior to muscle transplants (CP kids)
disadvantages of EMG
difficult technicaly
only gives semi-quantitative data
Muscle activation measurement systems
telemetry/tethered systems: - delays - biopac - noraxon - motion labs Surface EMG - (HPL lab) Need/fine wire EMG - timing, amplitude, fiber composition and fatigue
Muscle activation - methodology
16 EMG channels
simulatneous recording w/ motion and force data!!!!
muscle activation (timing and amplitude!!!)
- produces motion
- accommodates for pathology
Electrogoniometers
type of analysis = continuous measurement of joint angles
advantages of Electrogoniometers
easy to use and inexpensive
disadvantages of Electrogoniometers
may be too inaccurate for some movements
may modify gate pattern
old
mechanical Electrogoniometers were replaced by what?
strain-gauge Electrogoniometers (not used often)
motion analysis inc - vicon
shows you 3D image of body during gait
has the ability to tell you when muscle is contracting eccentrically/concentrically
goal = get descriptors of gait
disadvantage of full body analysis of motion measurement
hard for people to walk with natural gait like they do in normal environment when they are in the HPL lab
Kinematic systems
type of analysis = 3D measurement of limb motion
advantages of kinematic systems
complete description of joint movements
disadvantages of kinematic systesm
expensive, requires skilled personnel to operate equipment
Force platforms
type of analysis = detailed measurement of GRFs
measures forces and torques in 3 dimensions
advantages of force platforms
measures forces, which are invisible to eye
no interference with gait patterns
disadvantages of force platforms
very expensive
data of limited value when taken in isolation
kinetic/kinematic systems
combines kinematic system with force platforms
advantages of kinetic/kinematic systems
complete 3D description of motion
provides joint forces and moments
provides joint powers and energy transfers
disadvantages of kinetic/kinematic systems
expensive
requires skilled personnel
analysis of data from kinetic/kinematic systems
collects kinetic and kinematic data, goes into mathematical model that calculates forces, moments, and powers
Ambulatory systems for balance and gait assessment
objective: move measurement from lab to clinic, home etc
portable force place - relative motion - EMG
can take out of lab and into the indviduals normal environment
ambulatory gait monitoring system
portable for use anywhere
foot switches in shoe measure ambulation and transmit to accelerometers in box that you wear on your back
use for evaluation, feedback and re-training
