Research Areas

The on-going research in the lab is largely experimental in nature. With the development of experimental apparatus, experiments are designed and conducted to gather data. Applying system identification and neuromuscular modeling techniques, the data is analyzed and interpreted to help deduce underlying neural control strategies.

Development of Experimental Apparatus

REKLAB benefits from a hydraulic ankle actuator to gather experimental data, and is continuously enhancing the existing equipment. New actuators are being developed to study reflex contributions to upright walking and in the knee joint.

System Identification

New techniques in system identification are being actively pursued to increase accuracy and complexity, incorporate dynamic properties, and personalize models for individual subjects. Nonlinear, time-varying multi-input methods are becoming more accessible for neuromuscular systems applications. Future projects include integrating system identification methods to determine parameter values for a priori neuromuscular modeling.

Experimental Neurophysiology

This area of research concentrates on designing experiments, gathering data, and interpreting evidence to deduce physiological control mechanisms and strategies using system identification tools. Research questions include:

• Intrinsic and reflex stiffness in normal and spastic spinal cord injured subjects
• Exploring task-dependent modulation of reflex stiffness
• The role of reflex stiffness in upright stance

Neuromuscular Modeling

Recent modeling work (by Tatiana Nikitina) has yielded a symmetric, agonist-antagonist model capable of reproducing reflex modulation patterns. This work demonstrates that the known structure of the peripheral system can produce observed complex behavior. The lab continues to explore this avenue, incorporating descending commands from the central nervous system to motoneurons and interneurons selected to optimize different behavioral criteria.