An affordable and easy-to-use wireless device that uses four inertial sensors to detect lameness in horses has come a step closer after completing a preliminary study.
The system has proven its usefulness in identifying lameness and assessing its severity, Cristian Mihaita Crecan and his research colleagues reported in the journal sensors.
The device, named Lameness Detector 0.1, uses inertial sensors attached to the lower part of each limb to detect lameness.
The study team, with the Faculty of Veterinary Medicine at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca in Romania, said the results obtained in their study convinced them that further validation and standardization of the lameness detector 0.1 was warranted.
The end result is likely to be an affordable, easy-to-use and readily available device that, primarily as a screening tool, can assist equine veterinarians in their routine assessments of equine gait performance and lameness.
The study team said that while the classic lameness assessment is based on observation with some degree of repeatability and reliability, the human eye’s relatively low imaging frequency means that clinicians are unable to capture small changes in movement patterns.
Technological efforts in this area have focused on the use of multiple systems, such as B. force plates, optical motion capture systems and inertial measurement units.
Often recommended as the most accurate system, stationary force plates are the gold standard for objective assessment of lameness in horses, providing accurate and reliable results with high sensitivity and specificity.
However, the cost and complexity of the device and the need for controlled conditions and numerous environmental constraints, as well as the need for each limb to be removed and assessed separately, present major obstacles to conventional veterinary practices using these plates.
Optical motion detection systems can also be expensive and usually require laboratory conditions.
The study team’s paper described their efforts to design, develop and test an original system of devices to aid in the diagnosis of lameness under field conditions.
The Lameness Detector 0.1 System consists of four identical devices attached with adjustable and flexible straps to the front of each horse’s pasterns. The devices transmit data for processing and interpretation by software.
In order to disturb the natural gait as little as possible, four light and small components were connected together in each of the devices: a battery, an accelerometer, a microcontroller board and a Bluetooth device. The computer software named Lameness Detector 0.1 is custom written and open source. The biggest piece of any device is the battery.
Ten horses were used in the study, including six mares and four stallions. All had varying degrees of lameness in either a front or a hind leg.
The devices recorded data for five consecutive steps taken during a walk, sending the data from three axes for each leg for analysis.
The device demonstrated its usefulness in lameness detection and severity assessment, the study team reported, including the lowest subjectively detectable lameness.
The data showed identical dynamics for healthy legs, but significant differences between the healthy and lame legs on the X-axis. For both fore and hind limbs, acceleration values increased for the healthy limbs and decreased for the lame limbs.
Previous studies have also shown that vertical force peaks and impulses have high relevance in assessing lameness severity, they noted.
In discussing their work, the researchers said the term “lameness” is not limited to describing an apparent limp. This also includes subtle gait changes or reduced performance or willingness to perform.
Lameness, they said, is a pathological condition; a clinical problem that must be diagnosed in a timely manner from the earliest and slightest signs and treated appropriately to avoid further deterioration and permanent impairment of the animal’s locomotion.
Different terms are sometimes used to describe the gait of horses with conformational errors, training or shoeing errors, and unequal muscle development, such as:
“These animals were also implicitly considered to be quite lame and were awaiting a more definitive or thorough diagnosis to prove it.”
Equine medicine has continually evolved over the centuries to find the best possible lameness screening procedures.
“The paradox of this situation is currently happening with the advent of very sensitive objective gait analysis capabilities in horses, when veterinary medicine is faced with unexpected concerns and may need to re-define equine lameness to avoid overdiagnosis.
“Therefore, the integration of gait analysis technology into equine clinical practice is an ongoing process that requires careful monitoring.
“Ironically, the increased sensitivity in detecting slight gait asymmetries, which may be difficult for the human eye to observe in a classic lameness assessment, is seen as both a strength and a weakness of modern equipment for objective gait analysis.
“Although this sensitivity, accuracy and impartiality is purposefully pursued to allow for precise diagnosis at certain ‘thresholds’, the opposite concern is that when an asymmetry is so subtle that it is difficult to detect, its clinical relevance is not.” achieved can be safely certified.
“Taking all these aspects into account, our Lameness Detector 0.1 should be a screening tool to improve subjective lameness assessment.”
Used at the beginning of classical observation, it is intended to increase the practitioner’s attention to conduct a more thorough and detailed investigation when the data might indicate a problem.
The authors emphasized that an inertial sensor-based investigation cannot completely replace subjective clinical assessment, but can support it by improving and validating the accuracy and reliability of subjective results.
As the American Association of Equine Practitioners states, diagnosing and treating lameness is both a science and an art. It requires, on the one hand, a solid understanding of all structures involved in horse locomotion and requires adaptation to changing conditions, horse types, uses, personalities and owner needs.
“In this way, any equipment that supports the veterinary practice is valuable in its own right, without replacing the knowledge, experience, and even talent required to properly interpret the quantitative results.”
The study team consisted of Crecan, Iancu Adrian Morar, Alexandru Florin Lupsan, Calin Cosmin Repciuc, Mirela Alexandra Rus and Cosmin Petru Pestean.
Crecan, CM; Morar, IA; Lupsan, AF; Repciuc, CC; Rus, MA; Pestean, CP Development of a Novel Approach to Detecting Lameness in Horses Based on Inertial Sensors: A Preliminary Study. Sensors 2022, 22, 7082. https://doi.org/10.3390/s22187082
The study, published under a Creative Commons Licensecan be read here.