Updating the CGM

Future requirements

The context of clinical gait analysis has changed quite radically since the CGM was first developed. The most obvious is in the development of data capture technology but there have also been many wider changes in how services are delivered.

Clinical Governance

Clinical governance is a systematic approach to maintaing and improving the quality of patient care and focuses heavily on the implementation of evidence based practice. Healthcare delivery is now based upon standardisation of operations using formally document and validated procedures. Schemes such as those run by the Committee for Motion Lab Accrediation and the Clinical Movement Analysis Society accredit services in relation to how well these processed are documented, implemented and auditted. Currently the focus is on ensuring the minimum standard of full documentation of procedures but as this becomes routine the focus will shift to ensuring procedures are properly evidence based.

This may be augmented by increasingly stringent medical device legislation which now requires manufacturers to ensure that software is appropriately validated as well as hardware (which has been the focus in the past). Current legislation in many countries also effectively prevents local services customising software themselves and may lead to more standardisation around the software products provided by manufacturers.

Whilst in the past the limitations of the current biomechanical models for clinical gait analysis (including the CGM) have been addressed largely by ad hoc locally developed solutions there will be requirement in future to have better products delivered and properly certified by manufacturers.

Cost pressures

Throughout the world there is increasing cost pressures within healthcare. Gait analysis, as currently practiced, has a low throughput, high cost model which is extremely vulnerable within this context. Although equipment costs are reasonably high it is the staff costs that predominate. This is driven by techniques that are time consuming for data capture, processing and interpretaion and which rely on multiple professional staff with high levels of education for each of thes stages.

Solutions are required which are more time efficient and can be implemented largely by technicians rather than health professionals. Products are required which free health professionals to concentrate on the clinical intepretation and application of data. Being a reasonably simple and understandable model the CGM has tremendous potential to be developed to fulfil these requirements.

Technological Developments

It goes without saying that there have been immense technological developments since the initial development of the CGM. Mutliple markers placed virtually anywhere on the body can now be located with sub-millimetre accuracy and outputs can be generated in realtime. Hardware and software developments, however, have tended to be focussed on extending the range of what is possible rather than in consolidating best practice. Given what is possible technically now it is quite remarkable that reliable turnkey options for clinical gait analysis are not more readily available.

Over the last few decades an important revenue driver for systems manufacurers has been periodic equipment upgrades for existing experienced users as technology advancements have improved capture technology. A stage has now been reached, however, where further progress is limited by intractable problems such as soft tissue movement and biological variability between patients rather than measurement technology. This is reflected in recent developments from several manufactures focussing in peripheral aspects of product design rather than on core functionality. Future markets may thus be more driven by selling products to new inexperienced users rather than upgrading systems for experienced users. There will thus be a demand for stadardised robust techniques that can be easily adopted by new users rather than flexible products for experienced users.

Widening markets

A possible explanation for manufacturers failure to provide robsut turnkey solutions for clinical gait analysis has been the extremely wide range of contexts in which movement analysis sytems are currently used which span sport, human and animal biology, clinical research, psychology and the performing arts. Manufacturers have tended to want to develp generic products that could be applied in range of different contexts and have little interest in solutons tailored to particular specialities.

There has beem substantial growth in the volume of clinical gait analysis both through consolidation in regions where gait analysis has been available for several decades and in also in new regions. With such expanding markets it is quite likely that clinical gait analysis will emerge as a specialist market in its own right requiring products specific to its needs.

Potential for CGM2

This analysis suggests that there is a requirement for a standardised biomechanical model for clinical gait analysis. It should be validated suffiently to meet current clinical governance standard. It needs to be sufficiently rigorous to satisfy existing expert users but also simple enough to be easily adopted by new and less experienced users. The current CGM satisfies most of these requirements but is subject to a number of known limitations. It thus seems clear that a project to preserve those strengths while addressing its limitations will result in an model suited to future requiremetns of clinical gait analsysis.