Hilary Clayton is getting wired. Literally. She and her Arabian dressage horse, Magic, are their own subjects for this day's data collection at Michigan State University's (MSU) Mary Anne McPhail Equine Performance Center in East Lansing. Clayton, a PhD who received her veterinary degree from Glasgow University in Scotland, has spent a lifetime studying equine biomechanics. She leads the center's innovative research programs on equine movement and its effect on health and lameness issues. Her mission is to perform scientific investigations that directly benefit the sport of dressage.
On this day, her staff, including Joel Lanovaz – chief engineer and computer guru – and various graduate students, buzz around, attaching sensors and wires to Magic's reins. Then they glue eight electrodes to four muscles on both of Clayton's arms. Each electrode must connect with a corresponding wire and each wire, or channel, runs to a receiver strapped around her waist. A similarly attached wireless transmitter and amplifier will send signals to a nearby computer where information is collected and stored.
Magic's ears twitch, but he stands quietly as Lanovaz and Wesley Singleton – a student whose project is measuring rein tension – rip off strips of duct tape and wind them around the wires and boxes at Clayton's waist to keep them from jostling loose. Duct tape is an essential part of every experiment, they joke.
"What we're going to do today is a bit different," explains Clayton in a low-pitched British accent that belies her petite, 5-foot-4-inch stature. In previous sessions, her team has taken readings of a rider's forearm muscles by electromyography (EMG) – an instrument that converts the electrical muscle activity to a graphic image – and they have correlated the action of those muscles with the rein-tension data. Today, they also will take readings from the back and abdominal muscles. In the end, they want to quantify or measure how riders use their aids and how those aids affect the horse.
As Clayton and Magic – who was champion at his first outing at Third Level the previous weekend – move off at a walk, Lanovaz heads to the edge of the arena where his bank of computers and video monitors sprout wires and cables in every direction. He manipulates the program he developed to track the EMG movements. He also directs a student to videotape Clayton. Later, the video image and computer data will be synchronized.
It takes a while to adjust the connections to see if the signals are coming through correctly. "Move your left arm," Lanovaz calls out. Clayton makes a fist. "Have you got that?" she calls back. Lanovaz frowns and thinks deeper. There are reception problems, so he and Clayton decide that, for today, they will use only six channels, initially with electrodes on Clayton's arms, which later will be moved to the back and abdominal muscles. They are disappointed in not being able to use all eight channels, but there is always another day to sort out problems; such is the nature of research.
Everything done at the McPhail Center is new and requires patience in the developmental stages. Often the trick is to adapt technology originally designed for human studies to horses. Other pieces of equipment are fabricated from ground zero.
As adjustments are made, Clayton smiles wistfully. "It would be nice to have sensors built right into clothing and the saddle where they would be less likely to malfunction." She says that more channels receiving data from many locations on both horse and rider at the same time would be ideal.
With all systems working, Clayton begins to trot around the arena. As she rides past one section of the wall, she looks up at a 6-by-6-foot image of the computer screen projected there . She can see the chart of horizontal lines that erupt in peaks and valleys, illustrating the pounds of pressure exerted by her left and right reins. Two additional bars show EMG muscle activity in the triceps and deltoids of each arm. She explains what she is doing as a rider and there is more discussion about the instant results observed from the wall.
Singleton suggests how this technology can be a teaching tool for riders someday. "Picture this [computer] image projected onto a four-sided screen hanging from the middle of the arena for riders to watch as they ride. They could see at a glance how their position and aids are influencing the horse."
Magic comes to a halt, and Clayton releases the reins and pats his neck. "I don't think anybody has ever measured the pounds of pressure in rein contact together with the muscle activity patterns and synchronized it all with video recordings," she says. Now they can help riders understand what five pounds feel like in their hands. "One of the hard things we can't quantify yet is whether lightness is due to the rider just dropping the reins or due to self-carriage."
This is only the beginning for Clayton. "A project like this requires a large information base," she says. "We'd like to collect more data from good riders on familiar horses producing optimal work. We are looking for experienced clinicians to come and give a dressage clinic and at the same time be a part of the research. We like to have experienced trainers as our models, preferably riding more than one horse. Then we can make comparisons with less experienced riders and horses at different levels and gradually build our database."
Recently, California-based trainer Gerhard Politz gave a dressage clinic, and Clayton's team wired him up in much the same way. While riding, he told them what he was doing and why. More recently, Nancy Smith, the alternate for the 1999 Pan-American Games, participated in a similar manner.
Excerpted from the October 2001 issue of Dressage Today magazine.