Last week we had a demonstration of new gait analysis software from Qualisys. It showed nearly automated capture of data from treadmill running and immediate export of data to a web-based report. It was really slick by comparison with other packages that I’ve seen, for which the developers require credit. Let’s hope it stimulates some competition amongst manufacturers to deliver truly user friendly systems. I still felt, however, that it is a long way from what should be possible given current technology.
It caused me to go back to a document a wrote for myself in 2009 trying to map out what should happen in a clinical gait lab. It was my feeling that most of the technical elements described are currently available and all that is really required is for someone to stitch them all together. Here’s what I wrote:
The patient is welcomed at the door of the gait lab by a single gait analyst. The patient undresses to shorts and a t-shirt and the analyst attaches a number of markers quickly and easily to the patient. A small number of these have to be placed carefully but the others only need approximate locations.
The patient walks into the capture volume and stands still. The system detects they are standing still and captures the static trial. The patient performs the calibration exercises with or without assistance from the gait analyst (following a projection of what they are supposed to be doing on the wall of the laboratory). The system recognizes what they are doing and tells the gait analyst when sufficient calibration data has been captured.
Once this has happened the patient walks up and down several times. Data capture is automatic and when sufficient data has been captured the system tells the gait analyst that this is the case. If data is required in another condition then the gait analyst tells the system this and the capture of walking data is repeated. The whole process takes about 15 minutes if one condition is required and another 10 minutes for any other conditions.
The quality of the data is continuously monitored. The system is only recalibrated when the system detects that this is required. Markers rarely fall off but if they do the system will tell the gait analyst who simply replaces them and the system automatically recalibrates for the slightly different marker position. Because there is redundancy in the system, it will continue to work even if one or two markers have fallen off. The system analyses the data and alerts the analyst immediately if there are any suspicious features (such as too much knee movement in the coronal plane).
All data is processed in real time and stored as required. The data is collated automatically into a report which is available immediately the tests are complete.
The system has been standardized so that essentially the same process takes place no matter where in the world the analysis is conducted and data from all sites is directly comparable.
I emphasize that all the elements to achieve this are already available. All we need is one (or all of the manufacturers) to cobble them together into a streamlined package. The system I saw last week was moving in the right direction but its still quite a long way from the final destination.
There’s a paragraph I’ve missed out that might be a bit more controversial and may take a little longer to develop:
… This report is based around a computer graphic animation of the subject walking with interpretation tools alerting the clinicians to specific features of the gait pattern and how these are linked to the patient’s underlying pathology. If the clinician wants then it will also make treatment suggestions. The entire report is written in a language that is comprehensible to a health professional with reasonable clinical experience but no specific training in 3-d gait analysis. There are no gait graphs in the report (although these are accessible should the clinician be old-fashioned enough to want to look at them).
Note I haven’t forgotten the physical exam – I’ve just assumed that this will have been conducted somewhere else beforehand, either immediately before at the same visit or on some previous occasion.