André Schmidt Research Scholar / Postdoctoral Fellow

André Schmidt Research Scholar / Postdoctoral Fellow Ohio University College of Osteopathic Medicine Department of Biomedical Sciences 120 Life Sciences Building 45701, Athens, Ohio United States Email: schmidta@ohio.edu Phone: 740-593-0784

1999. 
      Final examination at the Integrierte Gesamtschule “Grete Unrein” in Jena, Germany
      

2000. 
      Civilian service at the Clinic for ophthalmology in Jena, Germany
      

2000-2002 Intermediate examination at the Friedrich-Schiller-Universität in Jena, Germany

Since 11/2010 Postdoctoral Fellow at Ohio University (A. R. Biknevicius` Lab)

My research interests lie predominantly in the functional morphology and comparative locomotor biomechanics of small to medium-sized mammals. Most studies on locomotion of small mammals to date have examined movements on horizontal and flat surfaces. In reality, small mammals must negotiate terrains that consist of numerous available substrates (fallen logs, branches). I am especially interested in the strategies used by animals moving on substrates that are smaller than the width of the animal’s body. For example, are there differences between mammals with- or without prehensile extremities? Which parameters define the transition between non-climbing and climbing locomotor modes and which locomotor strategies might be the locomotor strategies of early mammals? I am also interested in studying individual variability of locomotor adjustments caused by different environmental demands placed on the locomotor apparatus (e.g., substrate orientation).

For my diploma thesis I studied the treadmill locomotion of the round-eared elephant shrew (Macroscelides proboscideus, Macroscelidea, Mammalia). The goal of this study was to investigate the effects of different limb proportions on basic principles of locomotion in small

mammals. The results show that Macroscelides display the same locomotor adjustments as other small mammals, despite hindlimbs 25% longer than the front ones. A striking feature in the locomotion of this elephant shrew is the use of a “unusual” footfall pattern, where one limb is sustained in a constant bent position during the stance phase of the contralateral limb. Some of the results were presented at the 8th International Congress of Vertebrate Morphology (ICVM) and 100th Annual Meeting of the German Zoological Society (DZG).

1st Study – Arboreal locomotion in rats – the challenge of maintaining stability.
This study dealt with the “feat of moving” on small horizontal branches in a terrestrial mammal: the common rat (Rattus norvegicus). In order to maintain dynamic stability during branch locomotion the rats
displayed locomotor adjustments that have been observed previously in other clawed mammals (e.g., lateral sequence gaits, high velocities, similar contact times and peak vertical forces in forelimbs and hindlimbs). The results indicate, however, that clawed mammals and primates share several behavioral adaptations (e.g., reduction of peak vertical oscillations and side-to-side fluctuations) due to similar biomechanical constraints of small branch locomotion. One of the most interesting findings was the increase in spine movements as substrate diameter decreased. Read more…

2nd Study - Functional differentiation of the trailing and leading forelimbs during terrestrial and arboreal locomotion in the European Red Squirrel (Sciurus vulgaris, Rodentia).
	This study was conducted in order to test for differences in kinematics (e.g., 3D joint angles) and dynamics of the first (trailing) and second (leading) forelimb during locomotion on a terrestrial substrate and a horizontal branch. The results reveal that trailing forelimbs function exclusively as
shock-absorbing elements during small branch locomotion whereas a high-level of stiffness characterizes the leading forelimb. These differences in limb function are discussed in terms of an increase in stability, in particular on compliant arboreal substrates. Read more…

3rd Study - The kinematic consequences of locomotion on sloped arboreal substrates in a generalized (Rattus norvegicus) and a specialized (Sciurus vulgaris) rodent. The aim of the study was to determine which locomotor parameters the rat and the European red squirrel modify in response to substrate orientation of 30° and 60°. The data were compared with data pertaining to horizontal small branch locomotion captured in study I and II. Both species differ significantly in their preferred gait and therefore in their travel speed but numerous locomotor adjustments were surprisingly similar, perhaps due to the biomechanical constraints during locomotion on inclined small branches. The results of this study improve our understanding of climbing and support previous assumptions of highly standardized limb positions …

Since November 2010 I have been a Postdoctoral Fellow in the lab of Audrone Biknevicius at Ohio University. Ongoing projects include the individual differences in the locomotor performance of degus at different substrate orientations.

Andrada, E., Schmidt, A., Köhring, S., Mämpel, J., Fischer, M. S. and Witte, H. (2009). The effects of substrate inclination on torque patterns in rats. 3^rd International Symposium on Mobiligence in Awaji, Japan.