The pain and lameness horses with chronic laminitis experience are what make this disease a top concern in the equine veterinary community. Evaluating lameness severity, however, is largely subjective. At the 6th International Equine Conference on Laminitis and Diseases of the Foot, held Oct. 28-31 in West Palm Beach, Fla., David Hood, DVM, PhD, discussed the use of force plate-based technology for quantifying lameness severity in chronically laminitic horses.

Hood, who investigated the technology with colleagues at his Hoof Diagnostic and Rehabilitation Clinic (HDRC), in Bryan, Texas, explained that veterinarians typically diagnose chronic laminitis based on a horse’s display of lameness and the characteristic laminitis stance, with forelimbs placed out in front and hind limbs positioned under the body. They determine disease severity by assessing lameness, which is proportional to pain; a horse in severe pain has a grave prognosis.

In his observational study Hood evaluated 30 horses admitted to the HDRC and diagnosed with laminitis. He assigned each horse an Obel grade (from from I-IV, where IV is extremely lame and reluctant to walk), which among veterinarians is currently the accepted subjective method of evaluating lameness in horses with chronic laminitis. He also took radiographs (X rays) to define which of the horses’ feet were affected.

Each horse then stood on a force plate for five minutes so veterinarians could record the ground force reaction data, or how the horse was loading each foot. Researchers also calculated each horse’s center of load (COL) and how it differed from that of a normal, healthy horse. From this information–termed the mean load stance pattern–the researchers determined correlations between a horse’s stance and lameness; the COL and lameness; and stance and the foot involved