Kinematical motion analysis of the front legs of dogs suffering from osteoarthritis of the elbow joint during special physical therapy exercise regimes Introduction Aim of this study was the kinematical analysis of the forelimb of dogs suffering from cubarthrosis while going uphill, downhill and over obstacles (Cavaletti). Our general hypothesis was that during the performance of these 3 exercises the elbow joints of dogs suffering from cubarthrosis would show decreased flexion and extension in comparison to healthy ones. Material and methods 10 adult dogs of various breeds, clinically and radio-graphically diagnosed with elbow arthrosis, were used as test group for this study. 8 clinically sound adult dogs served as control group. For all dogs, ground reaction forces were evaluated on a treadmill with integrated force plates for kinetic gait analysis. Furthermore the dogs were equipped with reflecting markers on their forelimbs for kinematic analysis at the Motion Analysis Research Laboratory of the University of Veterinary Medicine in Vienna. Specially constructed Dog-Cavaletti were used for the Cavaletti experiments. The uphill and downhill exercises were carried out with an inclination of 11 %. Following parameters of the shoulder, elbow and carpal joint were used: maximal extension angle, maximal flexion angle and the range of motion of the joint (ROM). Results The statistical analysis showed that during the Cavaletti exercise the elbow joints of the lame and contralateral forelimb of the dogs suffering from elbow arthrosis had an increased flexion and a higher ROM than those of the healthy dogs. Furthermore, we observed that the elbow of the lame forelimb was less extended than the contralateral forelimb during the downhill exercise. During the uphill exercise, it could also be shown that the angle of the shoulder joint of the lame and contralateral forelimb of the dogs with elbow arthrosis had a decreased flexion, the contralateral shoulder joint also showed a decreased extension and ROM. In addition, it was ascertained that in comparison with its contralateral limb, the shoulder joint of the lame forelimb of the dogs afflicted with arthrosis had a stronger extension while going over the Cavaletti. The carpal joint of the lame forelimbs showed a smaller ROM during the uphill exercise than that of the healthy dogs. Conclusion Especially the results pertaining to the elbow joint during Cavaletti exercising were unexpected and surprising, so that our hypothesis that dogs suffering from elbow arthrosis have decreased extension and flexion in comparison to dogs that do not could not be affirmed. Thus the results of the kinematic gait analysis at hand convey new insights concerning the mechanics of joints of arthrosis patients and must be taken into account in further investigations of the musculoskeletal system and its orthopaedic diagnosis. In addition, kinematic control can be applied in the course of follow-up examinations after conventional or surgical therapy as well as in developing protheses. The precise knowledge of joint kinematics serves the optimization of therapy measures in the field of physiotherapy, in particular for active exercise therapy.