Horse on stall rest

A newer addition to the equine injury rehab tool kit, stimulation therapy, has grown in popularity among horse owners looking for noninvasive ways to help their athletes heal. Because research into this modality is new, one researcher sought to understand how it might be helping, and she produced measurable results.

“Many owners use vibration stimulation when their horses are injured and placed on stall rest, during which horses can develop atrophy (muscle wasting),” said Ashley Greene, a graduate student at Mississippi State University, in Starkville.

Specifically, Greene looked at the effects of this type of therapy on horses’ muscle thickness. She presented her results at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina.

While several therapeutic platforms exist, Greene used TheraPlate, which is marketed to increase bone strength and density, increase circulation within the hoof capsule, and improve or maintain muscle mass. TheraPlate is unique in that it uses vortex wave circulation (VWC) to deliver stimulating pulses to all four limbs simultaneously, said Greene.

At the beginning of her study, she placed eight mature stock-type horses in a 45-day moderate exercise program, then stalled them continuously for eight weeks “to mimic performance horses going on stall rest,” she said.

Four of the horses remained on stall rest throughout the study (the control group), while four also received VWC twice a day, five days a week. The researchers provided all horses with 2% of their body weight in hay per day. On Days 0, 14, 28, 42, and 56, Greene used ultrasound to measure thickness of seven muscles of interest in the horse’s back, rump, and upper limbs. She recorded increases in the treatment horses’ muscle thickness vs. the controls, most notably:

  • The extensor carpi radialis in the forearm increased in thickness by 30% after eight weeks of VWC;
  • The longissimus thoracis that runs across the back increased by 9%; and
  • The longissimus lumborum, a lower back muscle, increased by 8%.

“Both the longissimus thoracis and longissimus lumborum muscles are supporting muscles in the thoracic and lumbar regions, which are greatly relied upon by the equine athlete,” said Greene. “Therefore, VWC appears to be a viable option for minimizing, if not improving, muscle loss in performance horses on stall rest.”