Dr. Kacey Tweeten-King of Brock Veterinary Clinic in Lamesa, Texas, readies the Lameness Locator for an evaluation of a perfect candidate for the machine. The mare’s lameness was mild, and results showed problems in two limbs.

Performing lameness examinations has never been an exact science. Even the best equine veterinarians do not always agree on the cause or even the location of difficult lamenesses. Now, a relatively new piece of veterinary technology is taking the subjectivity out of lameness exams. 

The Lameness Locator was nearly 20 years in the making, but it is now gaining traction and popularity across the United States. It is not advertised as a replacement for good veterinary skills and knowledge, but as another tool for veterinarians, and perhaps soon for horse owners and even farriers.

The machine is particularly useful for identifying subtle, multiple and compensatory lamenesses, and assessing the effectiveness of nerve and joint blocks.

Development And Use

Kevin Keegan, an equine veterinarian and professor at University of Missouri’s College of Veterinary Medicine, set the wheels in motion in the early ’90s with a research project on identifying lameness through motion analysis. Over the years, and with the help of co-inventors P. Frank Pai and Yoshiharu Yonezawa, the Lameness Locator was born. The first unit was sold late in 2009, and the steadily rising number of machines in use today is over 50, 12 of which are in vet schools.

Marketed by Equinosis, Keegan’s limited liability corporation headquartered in Columbia, Mo., the Lameness Locator measures asymmetries of vertical torso acceleration to identify which limb or limbs have a problem, the severity of the lameness and in which portion of the stride the pain occurs. It cannot pinpoint the exact problem or area within the limb, and the data provided by the machine is fairly complex. There is no big red X that marks, for example, an aggravated navicular bone or sore hock. The veterinarian must still locate the exact cause of the lameness and, hopefully, cure it.


Covered with Elastikon for protection, the gyroscope is attached to the front right pastern.

Three inertial sensors placed on the horse collect data. There are accelerometers on the head and pelvis, and a gyroscope on the right front pastern. This information is transmitted wirelessly to a tablet computer. It is an odd-looking thing to watch a horse trot around with the sensors attached, particularly the sensor on the head, which is fastened to a foam pad connected to the halter, right between the horse’s ears.

New Tool, But An Expensive One

Brock Veterinary Clinic in Lamesa, Texas, uses a Lameness Locator on certain cases. Bo Brock, DVM, is a fan of most new lameness technology, and says veterinarians are now diagnosing things they could not even see 15 years ago. Brock and the other veterinarians at the clinic use the machine on about a quarter of their lameness cases, generally on the more difficult to see lamenesses.

“It’s just a tool that we didn’t have before,” Brock says of the machine.

Brock readily admits that lameness exams are subjective, which is one reason he likes the Lameness Locator.

“It takes the subjectivity out of lameness exams. It takes the art out of it and turns it more into a science,” Brock says.

Although the Lameness Locator helps Brock and his associates with difficult cases, it is not exactly a gold mine for the clinic. The purchase price is fairly high and the training is time-consuming. Brock says its use also increases the amount of time spent on a lameness exam, due to the thoroughness of the exam. However, Brock Veterinary Clinic charges a relatively small additional amount for using the Lameness Locator on a regular lameness exam.

“It’s probably not a new profit center for veterinary clinics, unless it brings in new clients,” Brock admits.

According to Keegan, the current price for a Lameness Locator and the online training is $15,000. A full warranty is available for 10% of the purchase price, which is discounted for veterinary schools.

Lameness Locators are only available for purchase by veterinarians, despite some interest by individuals.

“It’s a medical device,” says Keegan, “and it’s only marketed to equine veterinarians.”

However, a new, lower-cost model has been developed for horse owners. It has been tested and will likely be released later this year or in early 2012.

The Lameness Locator has both data acquisition and data analysis features, but the new model will only collect the data. That data must then be sent to a veterinarian, who must own a Lameness Locator, for the analysis.

This new model has many possibilities, although Keegan readily points out that a lameness cannot be diagnosed with it alone. The veterinarian must have previously examined the horse.

“It is just not enough. It is primarily for following up, or maybe for screening horses at large barns,” Keegan says.

Possible Farrier Use

There is also the possibility of horseshoers carrying this model, although Keegan had not yet given that much thought. When asked, he agreed it could be useful for farriers checking the progress of lame horses being treated with specific shoeing.


These Lameness Locator results show problems in the right front and right hind.

Brock is not certain how successful the new model will be. But many of his customers have shown interest, particularly those with expensive performance horses and those with large barns.

“I think there are a lot of untapped possibilities for preventative medicine,” Brock says. He makes note of using the machine to spot subtle lamenesses that likely would go unnoticed and might develop into something more severe without preventative action.

The new model will be marketed through veterinarians, with the intention of retaining the veterinarians’ support. The price has not been established, although Keegan says it will be significantly less than the $15,000 price tag carried by the original model.

One of Brock’s regular customers, professional barrel racer Lindsay Sears, thinks the new model could be beneficial.

“It would be nice when I’m on the road and my horse isn’t working great but isn’t dead lame,” Sears says.

In such cases, the machine might tell her whether she needs to make a trip to the veterinarian or not. That could save her considerable time, not to mention gas money. She recently drove 10 hours from a rodeo in Houston, just for Brock to look at a horse with a sore heel. But with the price of the new model still unknown, Sears is unsure whether the potential benefits would justify the expense.

Negative Views

Despite the increasing popularity of the Lameness Locator, there are some veterinarians who either do not believe in the technology, or who dislike the idea. Keegan is well aware of this.

“I really believe it is helpful for veterinarians. I really believe it is very good for the horse,” he says.

Keegan doesn’t believe that detractors are afraid the machine will decrease the importance of their specialty or level the playing field. He does think some lameness specialists may fear that inexperienced veterinarians might believe that the Lameness Locator will let them do that.

“It will not level the field. There is a lot more to analyzing lameness than detecting motion with high sensitivity,” Keegan reiterates.

The skepticism comes from several places, Keegan explains. Some veterinarians do not like the idea of using objective methods in lameness evaluations.

“It undermines their expert ability, and there is nothing you can say about that. That’s their personal opinion, and that’s the way it is,” Keegan says.

He finds it easier to counter the argument that the system is just a gadget that cannot possibly help with something as complex as equine lameness. Keegan admits that some people who see horses trotting around with sensors stuck to them think the whole thing is goofy. But Keegan counters by pointing out the amount of time and effort that went into the development of the machine, and emphasizes its positive results.

“Once they see that, then they realize that this is not a gadget,” says Keegan.

Another dislike, and one that may be remedied soon, is the name. Keegan admits it may give the wrong impression. The name was informally given by a vet student and it stuck, but there is a good chance that it will be changed.

For now, beyond the development of the horse owner’s model, other options are in the works for the Lameness Locator, including its use on other gaits, such as the foxtrot and the Saddlebred rack. Algorithms are also being developed that will allow the evaluation of lame horses at the canter instead of only the trot.