Center of Pressure (COP) analysis is an important tool that allows conclusions to be drawn about the patient's body balance. This balance can be altered by orthopaedic or neurological disease. To date, there are few data on the centre of pressure in the paws of dogs during gait. There are relatively few studies available in veterinary medicine, especially regarding COP in individual paws.
The aim of this study was to show the compensatory changes in the parameters of the centre of pressure in the paw during the standing phase in a walking dog, with data collected non-invasively while dogs with osteoarthritis and healthy dogs (control group) walked on a pressure platform. This study evaluated dynamic paw COP parameters during the standing phase in dogs with hip or knee arthritis (20 dogs for each) and 20 healthy dogs. Data were obtained by walking on a pressure platform and analyzed within the disease groups compared to the control group.
Both groups of diseased dogs showed significant differences between affected and unaffected limbs, but also compared to healthy controls. Dogs with OA (osteoarthritis) of the elbow or hip showed compensatory changes in both body weight distribution and COP parameters in the paws. The nature of these changes depends on whether the thoracic or pelvic limb is affected, but similarities can still be found between the two diseases studied. Significant differences can be found not only when comparing data from individual limbs of diseased animals, but also when comparing with reference limbs of healthy animals.
In dogs with hip osteoarthritis, the mediolateral COP shift was primarily increased, and in limbs with hip osteoarthritis, the COP-area was primarily increased in both pelvic limbs. However, in dogs with elbow osteoarthritis, there was an increase in medio-lateral COP shift in the ipsilateral pelvic limb and an increase in craniocaudal COP shift in the affected limb. Conversely, COP-area increased in both pelvic limbs. These changes may reflect compensatory redistribution of body weight as well as compensatory changes in body balance. The data and findings collected in this study in both diseased and healthy dogs could serve as a basis for even more in-depth research on paw COP, which could allow for future diagnostic use.
Reicher B, Tichy A, Bockstahler B. Center of Pressure in the Paws of Clinically Sound Dogs in Comparison with Orthopedically Diseased Dogs. Animals (Basel). 2020 Aug 6;10(8):1366. doi: 10.3390/ani10081366. PMID: 32781721; PMCID: PMC7459534.
