|
Most horse owners recognise that at some stage of their horse’s ridden career they are likely to require a veterinary or asymmetry assessment. Historically, lameness workups and gait evaluation were performed by eye by the attending veterinarian, but inter-observer disagreement [1], expectation bias [2] and limitations of the human eye to see asymmetrical movement [3] were common problems. The development of objective gait analysis systems and their introduction into equine orthopaedic practices appeared to herald a new technological era of lameness and gait assessment – technology which has been readily adopted by a number of clinicians and practices across the world.
But is our over-reliance on technology, and the potential limitations of gait analysis in lameness assessment versus the holistic assessment by an experienced orthopaedic veterinarian, benefitting or hindering routine lameness assessment in practice? Researchers from Utrecht University in the Netherlands sought to determine the pros and cons of quantitative gait analysis in their 2022 study, published in the Equine Veterinary Education journal.
Optical motion capture, the ‘Gold Standard’ kinematic gait assessment method, utilises skin markers to develop a 3D overview of the body within a calibrated area, and is known for its precision and accuracy. Body-mounted inertial measurement units (IMUs) can be utilised as an alternative method, which is increasingly popular due to its user friendliness, minimal amount of equipment required, and ability to be utilised in a wide range of environments. Despite both methods of gait analysis being highly accurate, their usefulness in equine practice and the motivation of clinicians using the technology, have not been well reported.
Hardeman and colleagues recruited 72 equine veterinarians to take part in their anonymous survey of experience, usefulness, examples of use and opinions on gait analysis IMU software. 55.6% of respondents were users and 44.4% were non-users of IMU systems. Of the commercially available IMU systems available, the Lameness Locator1 was the most commonly used. The majority of respondents (50%) currently utilising quantitative gait analysis in orthopaedic practice applied it in 0-25% of their clinical cases. In clinical cases, gait analysis appeared to be most commonly used during lameness assessment (85%), back/neck/pelvic issues (32.5%), sport horse monitoring (30%) and during pre-purchase examinations (27.5%).
Responding clinicians were additionally asked whether they believed incorporating IMU systems influenced their subjective judgement of lameness cases. A large proportion of veterinarians (60%) sometimes questioned their judgement during lameness assessment, and many (55%) believed using IMUs had altered their way of reviewing lameness cases. The main benefits cited were in cases of subtle lameness, poor performance, and after nerve blocking, in addition to being able to work more preventatively. Conversely, the negatives of using IMUs related to practical issues, including uncooperative horses, time-consuming methods, limited scope of outcome, poor assessment of asymmetrical issues, and difficulties in interpreting the results.
Despite issues with some of the software, 82.5% of respondents were positive about the use of IMU systems in equine clinical practice. General arguments against the use of IMUs by non-users were related to cost, over-reliance on technology and poor assessment of bilateral lameness. The ability to regularly monitor sport horses, standardise orthopaedic assessments and an objective assessment of all clinical cases were the overall benefits given for using gait analysis. Owners were generally considered to be appreciative of using IMUs (80%) and a large proportion of clinicians using IMUs (67.5%) believed it had benefitted their clinical skills.
Despite the largely positive assessment of quantitative gait analysis software use in equine practice, the rationale for its application in only 0-25% of clinical cases by many veterinarians is unknown, although some clinics were using IMUs in nearly 100% of orthopaedic cases. However, it does appear that using IMUs stimulates reflective practice in clinicians, improves objectivity, transparency and diagnoses when working with orthopaedic cases. The primary issues with IMU systems largely related to shortcomings of the technology itself, including inability to identify pain-related lameness from other asymmetries, and only vertical motion asymmetry able to be assessed. Whilst many clinicians were against the use of IMUs by non-clinicians (e.g. breeders, judges etc.), some respondents did highlight that their appropriate use, overseen by a clinician, may be useful in improving gait assessment knowledge of industry stakeholders, thereby positively influencing equine performance and welfare.
Although we live in a new, technological era, there is clear resistance from some clinicians and necessary software improvements before IMU systems will be used widely across equine orthopaedic veterinarians and first opinion practices. Whilst utilising IMUs may improve objectivity, transparency and diagnosis of some lameness cases, it is clear that there are no black and white answers and results still have to be analysed and interpreted carefully. The uptake of IMU use has to be driven by cost-effectiveness, ease of use, owner appreciation, support by companies developing and distributing software, and most importantly, clinician confidence in the reliability and usefulness of results.
For more information on this study, or to read the full article, please see https://doi.org/10.1111/eve.13505
| 
