title: Feasibility for Measuring Transverse Area Ratios and Asymmetry of Lumbosacral Region Paraspinal Muscles in Working Dogs Using Computed Tomography.
abstract: OBJECTIVE
  Describe computed tomographic (CT) anatomy of canine lumbosacral (LS) paraspinal muscles, a method for measuring paraspinal muscle transverse area ratios and asymmetry using CT, and application of this method in a small sample of working dogs with versus without LS pain.
  
  
  METHODS
  Published anatomy references and atlases were reviewed and discrepancies were resolved by examination of anatomic specimens and multiplanar reformatted images to describe transverse CT anatomy of LS region paraspinal muscles. Sixteen Belgian malinois military working dogs were retrospectively recruited and assigned to LS pain positive versus negative groups based on medical record entries. A single observer unaware of dog group measured CT transverse areas of paraspinal muscles and adjacent vertebral bodies, in triplicate, for L5-S1 vertebral locations. A statistician compared muscle transverse area ratios and asymmetry at each vertebral location between groups.
  
  
  RESULTS
  The relative coefficient of variation for triplicate CT area measurements averaged 2.15% (N = 16). Multifidus lumborum (L6-7), psoas/iliopsoas (L5-6, L6-7), and sacrocaudalis dorsalis lateralis (L6-7, L7-S1) transverse area ratios were significantly smaller in dogs with LS pain (n = 11) versus without LS pain (n = 5) (p ≤ 0.05). Muscle asymmetry values were not significantly greater in dogs with versus without LS pain.
  
  
  CONCLUSIONS
  Computed tomographic morphometry of LS region paraspinal muscles is a feasible objective method for use in future evidence-based research studies in working dogs. Potential future research applications include determining whether decreased paraspinal muscle area ratios and/or increased paraspinal muscle asymmetry could be used as markers for preclinical LS pain in stoic dogs or risk factors for other injuries in high performance canine athletes, or determining whether core muscle strengthening exercise prescriptions for dogs with LS pain have an effect on paraspinal muscle area ratios and asymmetry.
authors.affiliation: Division of Animal and Nutritional Sciences, Davis College of Agriculture, Natural Resources, and Design, West Virginia University , Morgantown, WV , USA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Cain
authors.affiliation: Division of Animal and Nutritional Sciences, Davis College of Agriculture, Natural Resources, and Design, West Virginia University , Morgantown, WV , USA.
authors.forename: Jeryl C
authors.initials: JC
authors.lastname: Jones
authors.affiliation: Office of Statistics, Davis College of Agriculture, Natural Resources, and Design, West Virginia University , Morgantown, WV , USA.
authors.forename: Ida
authors.initials: I
authors.lastname: Holásková
authors.affiliation: Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University , Blacksburg, VA , USA.
authors.forename: Larry
authors.initials: L
authors.lastname: Freeman
authors.affiliation: Department of Population and Health Science, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University , Blacksburg, VA , USA.
authors.forename: Bess
authors.initials: B
authors.lastname: Pierce
keywords: CT; canine; cauda equina; core muscle; lower back