Associate Professor Steven Lehman

Department of Integrative Biology

In the Motor Control Laboratory, directed by Dr. Lehman, research questions are asked on the human scale, and are answered at the most direct level, from cell to the entire person. Mathematical models are used to integrate results from the cell to the intact animal, and robots have been used to investigate the control of the simplest voluntary movements to the rehabilitation of stroke patients. The questions of immediate interest are: How do muscles stop movements? How does repetitive motion relate to muscle fatigue and to repetitive motion disorders?

A key aspect of the control of voluntary movements and locomotion is force production by muscles that are used as brakes. To find out how muscles act as brakes to stop movements, single muscle fibers are studied in vitro. The biomechanics of muscle fibers are used to construct mathematical models that simulate those mechanics, and test the models by varying the physical and chemical environment of the fibers. The research agenda is to characterize force production, energy storage and dissipation, then to extend the fiber model back up to the whole animal scale, comparing model predictions to experiments at each stage.

With the redesign of workplaces and work, ergonomists have begun to take an interest in fatigue that arises from non-forceful repetitive work. This may be the most common type of fatigue in the modern workplace. Currently experiments are carried on intact people to test whether fatigue is an indicator of cumulative repetitive work. This is the first stage in a long term plan to find the connection between fatigue and repetitive motion disorders.