Gait analysis in physiotherapy

• Gait measurement is a key part of physical therapy, giving insights into a patient's walking and overall mobility.
• Methods range from low-tech to high-tech, and understanding them helps physical therapists diagnose, treat, and monitor movement conditions.
• By module end, you should be able to analyze gait using Ranch Los Amigos (RLA) terms and describe gait aberrations using gait parameters and RLA terminology.

Overview of Methods

• Gait analysis uses various techniques and tools for physical therapists to understand walking; these methods include manual, observational, tech-assisted, and motion capture labs.

Manual Methods

• Manual gait analysis uses straightforward tools including paper measurements, stopwatches, timed outcome measures and floor markers

Observational Methods

• Observational gait analysis relies on the skills and expertise of physical therapists by using skills to observe and assess gait, using video playbacks to examine, and applying knowledge of gait parameters to identify deviations.

Technology-Assisted Methods

• Advanced technology plays a role in modern gait analysis for precise assessments, including slow-motion capture, gait mats for pressure/distribution, force plates for walking forces and shoe modifications for impact/correction.

Motion Capture Labs

• Motion capture labs combine manual and technological methods for gait analysis by using video recordings, force plates/mats, and renditions of anatomical markings to track movement.
• Each method provides unique insights, allowing physical therapists to choose appropriate tools for clinical needs.

Manual Measurement

• Manual gait can be measured physically by walking over paper with markings; a floor can have a foot length marked via tape for 10 feet-- a person walks and leaves footprints or is marked through a chalk line.
• Another way is to have a client walk over paper with paint on their feet to measure step and stride length but this measure doesn't capture the base of support variability or full body movements.

Stride Length

• Stride length refers to the distance from heel to heel of the same foot.

Step Length

• Step length refers to the distance from heel of one foot to heel of the other.

Foot Angle

• Normal foot angle is 50-70 degrees

Gait Velocity Definition

• Gait velocity refers to the speed at which a person walks, typically measured in meters per second (m/s) or feet per second (ft/s).

Timed Walk Test Definition

• Timed Walk Test is a functional outcome measure where a person walks a distance quickly, and time is recorded to assess walking speed, endurance, and mobility.

Step Length Definition

• Step Length refers to the distance between the heel strike of one foot/heel strike of the opposite foot, crucial for understanding stride mechanics and symmetry.

Stride Length (definition, tools)

• Definition: Distance between heel strikes of the same foot, indicating gait efficiency and lower limb functionality.
• Tools Used: Meter stick or tape measure, stopwatch.

Cadence (definition, tools)

• Definition: number of steps per minute (steps/min); a measure of walking rhythm and speed.
• Tools Used: Stopwatch, counting device.

Manual Assessment: Pros v Cons

• Pros: Low tech, no tools are required, inexpensive, can be done anywhere/anytime, some are standardized measurements
• Cons: Low tech, less accurate, requires practice/skill, environment can be inconsistent, familiarity with normal gait needed

Observational Gait Analysis

• Observational gait analysis is a method used to assess a person's walking and is a low-cost, non-invasive approach that can be done at home or in a clinic.
• During analysis, the therapist watches the person walk from behind/side to look for abnormalities like limping, weakness, or instability.

Apps for Observation

• For analyzing movement, consider Hudl Coach's Eye, Kinovea, OnForm, Vernier Coach, & Coach Now to analyze movement.
• Hudl: Allows sport video to be uploaded and analyzed with slow-down to examine player movement, technique, and game strategy with detail breakdown and controls
• Kinovea: Free software that allows you to analyze video with frame-by-frame playback, drawing to track movement, able to measure angles/distances.
• OnForm: App utilizes your smartphone's camera to track body movements and calculate joint angles with feedback to identify body imbalances or potential injuries.

RLA and JAKC Observational Gait Analysis

• Rancho Los Amigos National Rehabilitation Center developed the ROGA system, a widely used method for gait analysis. The JAKC gait analysis is a structured form that takes inspiration like the Rancho Los Amigos Gait Analysis (ROGA).
• Organization: broken into two main sections, stance and swing phases being subdivided for analysis
• Common Deviations: Identifies deviations from normal joint movement patterns in areas like the ankle, foot, knee, hip, or trunk
• Evaluation method: Evaluators use a check-box system to note presence in particular gait phase/sub-phase for documenting abnormalities Detailed analysis: The second page concludes identified deviations: spatiotemporal characteristics measurements like step length, step width, and walking speed to add further insight.

Observational Gait Analysis Pros v Cons

• Pros: simple/inexpensive using no specialized equipment, quick/efficient with fast assessment, real-time feedback to provide immediate support, functional assessment for providing real world ability, complements other methods for advanced techniques and comprehensive picture.
• Cons: Subjectivity relies on the therapist, limited detail without quantitative data, unsuitable for complex cases/slow movements, limited documentation is difficult to provide for future references.

Technology-Assisted Gait Measurement

• Technology-assisted gait measurement goes beyond observation and uses technology capture for detailed quantitative data of a peron's walking pattern, providing objective/precise understanding of gait mechanics.

Force Plates

• Force plates are embedded platforms to measure foot force exertion on the ground during phases of walking to give insight on weight distribution, impact forces, and balance.

Computer Measurements

• This refers to software programs that analyze various sensors data, like plates/mats: gait parameters step length, stride length, cadence, and foot placement/forces.

Inertial Measurement Unit (IMU):

• Inertial Measurement Unit (IMU) is an electronic device that measures a body's specific force, angular rate, and orientation being self-contained and not relying on external signals.

Key Components/Functionalities within an IMU

• Gyroscopes: measure angular rate of rotation around an axis measuring which direction/speed a wheel spin.
• Accelerometers: measure velocity (e.g., detecting if body stands still, accelerations, and decelerations.)
• Magnetometers (Optional)- detects Earth's magnetic field. How IMUs Work
• Gyroscopes/accelerometers measure properties to estimate body's orientation with the algorithms for pitch, roll, and yaw.
• Position by integrating acceleration data accounting gravity, estimating body's change of position that tends to drift; commonly paired with GPS accuracy.
• They can analyze of orientation/position to allow motion, include speed, direction, and changes of direction

IMU applications

• IMUs can be used in many areas like robotics, automation, rehabilitation, and automotive industry.
• IMUs are used monitor gait analysis, track movement patterns, and measure balance in rehabilitation.

Technology Assisted Gait Analysis Pros v Cons

• Pros: relatively easy to use, less expensive than motion analysis, portable.
• Cons: limited temporal /spatial, minimal steps

Motion Capture Labs

• Motion capture labs are specialized facilities using high-tech to record and analyze human or object movement in 3D.

Cameras

• High-resolution cameras capture the movement of reflective markers placed, recording the position, allowing 3D movement data.

EMGs

• While not always present, some labs might incorporate sEMG sensors attached to the skin over specific muscle groups to measure electrical activity to allow researchers to understand the relationship between movement.

Passive Reflective Markers

• Small, spherical used in motion capture systems to track movement of a person or object being "passive"; they don't emit light but rely on external source.

Force Platforms

• Force Platforms are embedded and measure the force exerted to analyze weight distribution, balance, and impact for valuable research in analyzing data into gait analysis and biomechanics.

IR Video Camera

• IR Video Camera captures images and videos via IR (invisible to the naked eye). Differentiation of IR from Visible Light

Thermal Imaging Cameras

• Detect heat emitted to make video where warmer is brighter, helping in dark areas.

Night Vision Cameras

• Night vision cameras use IR to improve visibility in lighting with a special sensor to capture a clearer image for military or wildlife studies.

Technology Motion Capture Lab Analysis Pros v Cons

• Pros: To capture joint kinematics/kinetics in planes, accurate, good and can sync EMG data
• Cons: Needing dedicated space, requires more processing and expert knowledge and skin artifacts.

Summary

• The information to choose the right gait analysis depends on several factors relating to patient needs with a breakdown of considerations
• Spatial-temporal information- focuses on attributes such as step length, stride length, cadence, and velocity, for a basic understanding of gait efficiency
• Outcomes- helps understanding if they are showing patient results: identifies changes, and intervention effectiveness
• Kinematic/Osteokinematic: evaluates/analyzes joint motion during gait. The volume of data will be dependent on issue

Observational Gait Analysis:

Requires basic equipment; perfect for initial assessments.

Gait Analysis App

• smartphone apps can measure basic elements, appropriate.
• However, these apps are limited since they only provide basic analysis

Plates and Pressure Mats

• provide value on the distribution.
• This is a good method because is gives data that can impact weight bearing

Motion Capture System

• complex systems are used to analysis more difficult gaits but are very specialized

Analysis of typical gait- Part II

• Subject(s) - PhysioU (Home) → Gait → Analyze → Normal Gait
• https://app.clinicalpattern.com/gait/2409/p7010/

Open Assessment tool - JAKC Analysis tool

Organization

• Toes upward to head/trunk View: Side - Rear - Front. Swing v. Stance

Tools to Use in Observational Gait Analysis

• Rancho Los Amigos (RLA)
• JAKC Gait Analysis

Key things to look at:

• Look at Each Joint/Segment for: - Ankle/Foot, Knee, and Pelvis and hip

Calculating stride

Here are several ways to measure the stride, each measuring: • Velocity (m/min or m/sec) • Cadence (steps/minute) • Stride Length (meters)