October 26, 2015

The reliability of goniometry in Labrador Retrievers

How reliable is goniometry (measurement of angle of movement in a joint) in Labrador retrievers? Goniometry is reasonably reliable for the measurement of limb flexibility in Labrador retrievers and humans. While the reliability has been tested in humans this group is proving it for dogs. The investigators believe that there could be variation based on whether the dog is sedate or awake, different people doing measurements, one person doing multiple measurements, the measurements done on the first and last 5 dogs, and radiology vs. goniometry. There couldl also be less variation between measurements in distal joints than in proximal joints.

Goniometry measurements will be compared to those done by radiography and tested for accuracy. They will also be done by multiple testers so that the there is a comparison between testers as well as a set of data for that tester. There were 16 Labrador retrievers in the study, 6 male and 10 female, with an average age of three years. None of the dogs had a history of joint problems. One forelimb and hind limb, on the same side, were evaluated on each dog. There were positions evaluated on each dog and each position was measured three times once by each tester. A set of measurements was made while the dogs were awake and a set while they were asleep. A single dog who only had three points measured, was measured five times by one investigator to test variation between single investigators. There was a time lapse of 15 or more minutes between measurements. To test the reliability the goniometer was placed based on anatomical markings and then aligned with the axis of rotation. Before each joint was measured the rotational ability of the joint was established by rotating the joint. All measurements were recorded by an independent observer. The investigators could only see and move the arms of the goniometer. For the radiography measurements the dogs were first sedated then radiographs were made with the limbs in maximum extension and maximum flexion. During the sedated time period they also repeated goniometric measurements. The radiographs were then measured by one investigator using identical anatomical markers as in the goniometric measurements.

The researchers found that there was little variation between sedate and awake dogs and that those results were similar to radiographic measurements. There were also not significant differences in the measurements done by the three different investigators. There was also no significant variation in the measurements done by the single investigator over a long period of time nor was there any significant difference in the measurements of the first and last five dogs measured. They chose Labrador retrievers due to the fact that they are the breed most often registered with the American Kennel Club (2000) and because they have relatively constant features. For these Labrador retrievers goniometry was accurate and repeatable.

Figure 1 depicts what joints were measured and the specific angles that were examined.

Jaegger, G., Marcellin-Little, D., Levine, D., 2002 Reliability of goniometry in Labrador Retrievers. American Journal of Veterinary Research 63: 979-986

Retrieved from: http://avmajournals.avma.org/doi/abs/10.2460/ajvr.2002.63.979