Non-invasive assessment of equine muscular function: A case study

Assessment of muscle function after an injury or during recovery is of great importance in the veterinary field. Accelerometry, bioimpedance analysis and mechanomyography/acoustic myography have been used to assess human muscular problems, but have not been applied to the veterinary clinic. We report the clinical use of these techniques in a 12-year-old Danish Warmblood horse presenting with recurring and shifting lameness. Acoustic myography, assessing both the amplitude and frequency of active muscles, was employed to locate the specific area of muscle injury, the right hip, which exhibited minimal fibre recruitment giving rise to considerable weakness. This specific region was assessed by accelerometry which revealed a normal step interval for the injured leg when compared with the contralateral, but a weaker acceleration and strike force. Finally, an assessment of muscle resistance (R) and reactance (Xc) using bioimpedance confirmed a regional loss of muscle mass and a loss of cellular integrity compared with the contralateral limb.