What is a gait analysis?

A gait analysis is an assessment technique often used by clinicians to analyse the way that their clients walk or run. The purpose of it is to assess if the gait is contributing to any problems that they may be having and to help plan any interventions that may be needed to change the gait to help with those problems. It is simply a matter of watching someone walk, but highly sophisticated equipment and mathematical analysis can be done. At one end of the spectrum would just be a visual analysis of the way that someone walks, but the problem with that is that many events of the walking cycle happen so quickly for the eyes to see properly. The are many apps now available for smartphones to video the way that someone is walking or running and then slow the frames per second down on replay to do a more thorough analysis. At the other end of the spectrum is the sophisticated 3D analysis that is done with lots of markers attached to the body and the use of multiple cameras that a computer then converts into a 3D replay of the gait.

There are other ways of assessing the gait such as using systems that measure muscle activity or pressures under the feet. These other methods may be used with the above systems to give a complete overview of the gait of a person. What system is used and just how in-depth the analysis is done will be dependent on the nature of the clinical issue that the patient has and how complex it is and how complex that the intervention needs to be. Research laboratories also use various systems for research and they often use equipment at the more sophisticated end of the options.

One of the fundamental issues is the difference between a 2 dimensional (2D) and a 3 dimensional (3D) analysis. A 2D analysis costs less, but a 3D analysis provides more information. A 2D analysis only typically looks at motion in one plane or direction and is analogous to looking at a photo. It is typically done with just one video camera. A 3D analysis looks at motion in all directions, so uses multiple cameras and relies on significant computing resources to combine all the data from the three cameras.

Another fundamental decision is the use of a treadmill. A treadmill means that the client can be analyzed in one place at the same consistent speed on multiple occasions. An overground analysis makes it harder to control for the speed, especially on subsequent days. The other problem is that there are a number of variations between the gait on a treadmill versus a gait overground, so it may not be a true representation of how someone walks or runs.

A lot of the issues surrounding gait analysis, especially the use of 2D and 3D in clinic was discussed with an expert, Chris Bishop in an episode of the podiatry livestream, PodChatLive. In the episode the hosts chatted with Chris about the options that clinicians have to use in their day-to-day clinical practice.

Craig Payne is a University lecturer, runner, cynic, researcher, skeptic, forum admin, woo basher, clinician, rabble-rouser, blogger and a dad.