P2.192 Thursday, Jan. 5 Kinematic, kinetic and electromyographic analysis of the locomotor ontogeny of the Beagle HELMSMÜLLER, D.; WEFSTAEDT, P.; NOLTE, I.; SCHILLING, N.*; Small Animal Clinic, University of Veterinary Medicine Hannover; Small Animal Clinic, University of Veterinary Medicine Hannover; Small Animal Clinic, University of Veterinary Medicine Hannover; Institute of Systematic Zoology and Evolutionary Biology, Friedrich-Schiller-University firstname.lastname@example.org
Juveniles must perform in the same environment as adults while their body undergoes continuing changes in body size and proportions and their musculoskeletal system progressively matures. To better understand how young altricial mammals cope with these changes and analyze which locomotor parameters change during ontogeny, we studied the locomotor development in dogs. We used six male Beagle siblings in this longitudinal study and collected data every week to two weeks starting at the age of 9 weeks. Kinematic, kinetic and electromyographic data were collected synchronously while the puppies walked and trotted on an instrumented treadmill. Each gait was performed at the same Froude number throughout ontogeny to circumvent locomotor differences due to body size. Additionally, morphometric data were collected to capture the development of body and limb proportions. Confirming previous results, the typical mammalian intralimb re-proportioning was observed, i.e., distal segments decreased while proximal segments increased in relative length. Epaxial muscle activity was nearly adult-like in its timing by the age of 9 weeks. Likely connected with the changes in body proportions, the relationship of the peak vertical forces between the fore- and hindlimbs shifted from the forelimb supporting a relatively greater proportion of body mass in the puppies in comparison to adults. The results of this study increase our understanding of the dog’s locomotor ontogeny in particular and of mammals in general.