Gait analysis is the study of animal locomotion, including locomotion of humans. Gait analysis is commonly used to help athletes run more efficiently and to identify posture-related or movement-related problems in people with injuries.
The study encompasses quantification, i.e., introduction and analysis of measurable parameters of gaits, as well as interpretation, i.e., drawing various conclusions about the animal (health, age, size, weight, speed, etc.) from its gait.
Gait analysis commonly involves the measurement of the movement of the body in space (kinematics) and the forces involved in producing these movements (kinetics).
Kinematics can be recorded using a variety of systems and methodologies:
1. Photography is the most basic method for the recording to movement and strobe lighting at known frequency has been used in the past to aid in the analysis of gait on single photographic images.
2. Video recordings using footage from single or multiple cameras can be used to measure joint angles and velocities.
3. Passive marker systems, using reflective markers (typically reflective balls), allow for very accurate measurement of movement using multiple cameras (typically up to 8 cameras simultaneously)
4. Active marker systems are similar to the passive marker system but use “active” markers. These markers are triggered by the incoming infra red signal and respond by sending out a corresponding signal of their own.
Applications
1. Medical diagnostics
Pathological gait may reflect compensations for underlying pathologies, or be responsible for causation of symptoms in itself. The study of gait allows these diagnoses to be made, as well as permitting future developments in rehabilitation engineering.
Aside from clinical applications, gait analysis is widely used in professional sports training to optimise and improve athletic performance.
2. Biometric identification and forensics
Gait analysis techniques allow for the assessment of gait disorders and the effects of corrective orthopedic surgery. Options for treatment of cerebral palsy include the paralysis of spastic muscles using Botox or the lengthening, re-attachment or detachment of particular tendons. Corrections of distorted bony anatomy are also undertaken. It is heavily used in the assessment of sports and investigations into the movement of a large variety of other animals.
Minor variations in gait style can be used as a biometric identifier to identify individual people.
Gait analysis (Wikipedia)
Motion analysis theory (Kwon3D)
