Choosing a clinical gait analysis system

I’ve had a recent query about which gait analysis system I would recommend for a new clinical service. The simple answer is that I wouldn’t recommend any particular system. I only have practical experience of two and it would be silly of me to contrast my in depth experience of those and with my comparative ignorance of their competitors.

I do know that the two systems I currently work with both work well and deliver far higher spatial and temporal resolution than I required for any of the clinical work I am doing at the present. Given that most systems these days deliver more than the general user requires, there is little point in trying to differentiate between them on the basis of their technical performance (unless of course you have some really specific requirement that demands cutting edge equipment).

If it isn’t technical performance that guide’s your choice what should?

Ease of use

Neither of the systems I use delivers data as quickly and efficiently as I think they should for clinical gait analysis purposes (and I haven’t seen any others that do either). Clinical gait analysis must be a large part of the market for new systems in the life sciences field throughout the world. It has fairly tightly defined user requirement and it amazes me that none of the manufacturers has developed a really streamlined workflow for data capture and processing.  It baffles me that they’ve invested so much in getting real-time output for some purposes but that it still seems to take so long and requires so much human interaction to deliver a sheet of graphs for clinical gait analysis purposes.  I’d really encourage any potential purchaser of a new clinical system to ask the manufacturer for a demonstration of how independently (from human interaction), smoothly and quickly it can deliver formatted gait graphs.

Support

For new gait analysis facilities support is a key issue. This links into the point above in that few systems have a clinical gait analysis work-flow so well worked out that you can open the box, plug the components together and start doing clinical gait analysis. You are almost certain to require support to help you to do so and it should really be the manufacturer (or re-seller) that provides this.

Evaluating the support of different manufacturers is interesting. I’ve had excellent support from both manufacturers I deal with – but then I would wouldn’t I – I’m a figure of some influence in the field that writes articles like this! Manufacturers would be daft not to provide high level support to me and my colleagues. (Having said this I’ve always received excellent support – even before my name was so well known). Talking with other gait analysts, however, gives a bewildering range of replies. It amazes me how different users of the same systems can have such radically different opinions of the quality of support that manufacturers deliver. Some will be extremely flattering and can’t recommend a company too highly while others will be extremely negative about the same company.

How can this be? The most obvious reason is that support is delivered by individuals and it is quite possible that different individuals will be more supportive than others within any team. How you rate the support you receive might depend heavily on the individual that delivers it rather than on the company they work for. I also get the feeling that there are geographical variations in how some manufacturers organise and deliver support. In some parts of the world this involves re-sellers being the primary providers of support. My advice here would be to speak to users of systems as close to your locality as possible to see how they rate support services. And remember not to be flattered by the attention you appear to be getting before you sign the cheque. It is the support you get afterwards that counts!

A final point here is that the quality of support is a two way process. Good support requires the gait analysis service to have staff who are capable of asking the right questions, of understanding the replies given and acting appropriately afterwards. I suspect that many (but by no means all) support problems result from local staff not really having the basic competencies to operate systems and trouble shoot problems in the first place.  Every so often I get asked to review plans for a new service and these often include provision for huge amounts of expenditure on new buildings and facilities and equipment and no provision at all for someone genuinely competent to operate the equipment once it is delivered.

Cost

Cost may or may not be an issue. Many hospitals managers don’t understand gait analysis and this can work two ways. Some can be overly conscious of their own ignorance and accept almost any justification for expenditure. Others will insist on the standard three quotations and accept the cheapest regardless of the detailed specifications . In this case it is extremely important that you work to specify the system and (ongoing support) appropriately before asking for quotations in order that only those manufacturers who can genuinely supply what you want are able to tender.

There are a number of very low cost competitors emerging in the movement analysis market. Indications are that the technical performance for relatively undemanding applications such as the recording the kinematics of people with disabilities walking is quite acceptable. If this is all you require then fine. You need to be really careful, however, if you want to integrate force plates, EMG systems or synchronised video that this is possible and straightforward. You also need to be ensure that there is adequate software for processing and presenting the data you have captured. In many parts of the world you will need to ensure that the systems have appropriate registration as medical devices in order that they can legally be used for clinical purposes. Following on from my earlier comments it is important to remember that, although manufacturers of these cheaper systems may be happy to sell to anyone, clinical gait analysis is unlikely ever to be their core market and the quality of their support is likely to reflect this.

A final point is that even the cost of more expensive systems have dropped radically over the last ten years. In the context of the staff and space costs of running a gait analysis service over five or ten years the cost of the equipment is now quite modest. Cutting costs by purchasing a cheaper system which requires higher staffing levels to keep it running is likely to be a false economy.

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2 comments

  1. Mohammed,

    As I’ve said in the blog I’m reluctant to offer an opinion on technology I’ve got no personal experience of. I do suspect that treadmill based gait analysis is likely to become more and more common over time even for clinical services. I suspect that at some time in the future we might all look back at the current overground laboratories and wonder how we could waste so much space. The main limiting factor here to my mind is the validation of force plate measurements made on instrumented treadmills. I’ve not yet seen a convincing study yet that such measurements are comparable to those made by conventional treadmills.

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