Biomechanics and Motor Control Lab

Centennial Research Building, room 119
Phone:404-894-1032, Fax:404-894-7593

Research Interests

The major research focus of the laboratory is on biomechanics and motor control of locomotion and reaching movements in healthy people and individuals with neurological and musculoskeletal pathological conditions. In particular, we study the mechanisms of motor learning and adaptation to novel motor tasks as well as to pathologic conditions of the neuromusculoskeletal system caused by injury (stroke, peripheral nerve or spinal cord injury, and amputation). We also investigate how motor practice and sensory information affect selections of adaptive motor strategies.

Personnel

• Director: Boris I. Prilutsky, PhD
• Postdoctoral Associate: Alexander N. Klishko, PhD, Margarita Bulgakova, Ph.D.
• PhD Students: Lee Childers, BS, MS; Linda Harley, BS, MS; Brad Farrell, BS; Zhengqin Fan, BS
• Master Student: Gregory Phillips, BS
• Undergraduate Students: Shivani Shah
• Collaborators:
  • Irina N. Beloozerova, PhD, Barrow Neurological Institute, Phoenix, AZ
    Carlo L. Bottasso, PhD., Politecnico di Milano, Italy
    Gennady S. Cymbalyuk, PhD, Georgia State University, Atlanta, GA
    John F. Dalton IV, MD, Georgia Hand & Microsurgery, Atlanta, GA
    Donald Edwards, PhD., Georgia State University, Atlanta, GA
    Art English, PhD, Emory University School of Medicine, Atlanta, GA
    Robert J. Gregor, PhD, Georgia Tech; University of South California, Los Angeles, CA
    Robert Kistenberg, MPH, CP, LP, FAAOP, Georgia Tech
    Michel Lemay, PhD, Drexel University College of Medicine
    Peter Lum, PhD., The Catholic University of America, Washington, DC
    David McCrea, PhD, University of Manitoba, Canada
    Melody Moore-Jackson, PhD, Georgia Tech
    Sara Mulroy, PhD; PT, Rancho Los Amigos National Rehabilitation Center, Downey, CA
    T. Richard Nichols, PhD, Georgia Tech
    Mark Pitkin, PhD, Tufts University School of Medicine, Boston, MA
    Ilya A. Rybak, PhD, Drexel University College of Medicine
    Masahiro Sekimoto, Ph.D., Ritsumeikan University, Japan
    Steven L. Wolf, PhD, Emory University Rehabilitation Medicine, Atlanta, GA
    Vladimir M. Zatsiorsky, PhD, Penn State University, State College, PA

Current Research Projects

• Neuromusculoskeletal Modeling and Computer Simulation of Spinal Locomotion
  In this project our laboratory develops a comprehensive musculoskeletal model of spinal locomotion that is capable of generating realistic mechanics of walking and computing sensory feedback form the muscles and skin. The simulated walking and the feedback signals are computed based on the dynamic equations of limb and muscle dynamics and experimentally recorded muscle activity used as input. The musculoskeletal model will be integrated with the computational model of locomotor Central Pattern Generator (CPG; Rybak, McGrea, et al., 2006) through feedback and feedforward connections. This integrated neuromusculoskeletal model will allow for detailed investigations of the structure and functions of CPG and the role of proprioceptive feedback in regulation of its activity.
  

  

• Sensorimotor Control of Locomotion after Peripheral Nerve Injury
  In this project we investigate (1) mechanical responses of the local musculoskeletal system to peripheral nerve injury and repair, (2) short-term changes in muscle coordination in response to peripheral nerve injury, and (3) contributions of proprioception from intact muscles to long-term motor adaptation to the loss of feedback from affected muscles. This project involves close collaboration with Dr. Gregor (Georgia Tech, USC), Dr. English (Emory University), and Dr. Nichols (Georgia Tech). Spinal circuitry and mechanical consequences of loss of proprioception are simulated in collaboration with Dr. Edwards (Georgia State University) using software AnimatLab developed in his group.
  

  

• Motor Adaptation and Learning in Arm Reaching Tasks
  In this project we study how motor practice of novel reaching tasks and visual and proprioceptive feedback from the arm affect the speed of learning and acquisition of specific motor strategies. We investigate how and why certain invariant characteristics of skilled reaching (straight-line endpoint trajectory, bell-like endpoint velocity profile, the accuracy-speed tradeoff, specific patterns of muscle activity, etc.) are acquired during motor practice.
  This research has important applications to rehabilitation. In a related exploratory collaborative project with Drs. Lum (The Catholic University of America), Mulroy (Rancho Los Amigos National Rehabilitation Center) and Wolf (Emory University), we use kinematic and EMG measures of reaching and grasping tasks in individuals with stroke to quantify the recovery patterns after physical therapy interventions.
  

  
  

• Direct Brain Interfaces for Stroke Rehabilitation
  In this exploratory project we collaborate with the group of Dr. Moore-Jackson (Georgia Tech) to determine if a Direct Brain Interface based on real-time electroencephalographic recordings can be successfully integrated with a rehabilitation robot to provide therapeutic options for people with severe motor disabilities.
  
• Mechanics and Control of Precise Stepping
  In this collaborative project with Dr. Beloozerova (Barrow Neurological Institute) we ask how accurate stepping movements are organized and achieved and what are the biomechanical and neural mechanisms of accurate locomotor movements. We address these questions by assessing full-body mechanics, limb muscle activity, and activity of motor cortex during locomotor task with different demands on the accuracy of foot placement. Our subjects walk on a continuous flat surface, on horizontal ladders with rungs of different widths, and along narrow pathways.
  
• Innovations in Lower Limb Prostheses Attachment
  This collaborative project with Dr. Mark Pitkin (Tufts University), Dr. John F. Dalton IV (Georgia Hand, Shoulder & Elbow) and Robert S. Kistenberg (Georgia Tech) focuses on the development of the Skin and Bone Integrated Pylon that is intended for direct skeletal attachment of limb prostheses.
  

  

Research Opportunities

Research opportunities related to the projects listed above are available for graduate and undergraduate students. Dr. Prilutsky is also a faculty member of the Georgia Tech's Bioengineering Graduate Program. Undergraduate students interested in research opportunities in the lab are encouraged to apply for the President’s Undergraduate Research Awards.

Funding

• 2006-2011, NIH Bioengineering Research Partnership grant NS048844 – Rybak (PI): “Spinal Control of Locomotion: Studies and Applications”
• 2007-2012, NIH Program Project Grant HD032571 – English (PI): "Sensorimotor Control of Locomotion after Peripheral Nerve Injury".

Recent Publications

• Maas H, Gregor RJ, Hodson-Tole EF, Farrell BJ, Prilutsky BI. Distinct muscle fascicle length changes in feline medial gastrocnemius and soleus during slope walking. Journal of Applied Physiology (2009, in press).
• Pitkin M, Raykhtsaum G, Pilling J, Shukeylo Yu, Moxson V, Duz V, Lewandowski J, Connolly R, Kistenberg RS, Dalton JF IV, Prilutsky BI, Jacobson S. Mathematical modeling, mechanical and histopathology testing of the porous prosthetic pylon for direct skeletal attachment J Rehabil Res Dev. (in press).
• Prilutsky BI, Klishko AN, Farrell B, Harley L, Phillips G, Bottasso CL. Movement coordination in skilled tasks: Insights from optimization. In: Advances in Neuromuscular Physiology of Motor Skills and Muscle Fatigue (Shinohara M Ed.), Research Signpost (accepted).
• Maas H, Prilutsky BI, Nichols TR, Gregor RJ. The effects of self-reinnervation of cat medial and lateral gastrocnemius muscles on hindlimb kinematics in slope walking. Exp Brain Res. 181(2): 377-393, 2007.
• Bottasso C.L., Prilutsky B.I., Croce A., Imberti E., Sartirana S. A numerical procedure for inferring from experimental data the optimization cost functions using a multibody model of the neuro-musculoskeletal system. Multibody System Dynamics 16: 123-154 (2006).
• Gregor R.J., Smith D.W., Prilutsky B.I. Mechanics of slope walking in the cat: quantification of muscle load, length change, and ankle extensor EMG patterns. Journal of Neurophysiology 95:1397-1409 (2006).
• Prilutsky B.I., Sirota M.G., Gregor R.J., Beloozerova I.N. Quantification of motor cortex activity and full-body biomechanics during unconstrained locomotion. Journal of Neurophysiology 94: 2959-2969 (2005).
• Ivashko, D.G., Prilutsky, B. I., Markin, S. N., Chapin, J. K. and Rybak, I. A.. Modeling the spinal cord neural circuitry controlling cat hindlimb movement during locomotion. Neurocomputing 52-54: 621-629 (2003).
• Prilutsky, B.I. and Zatsiorsky, V.M. Optimization-based models of muscle coordination. Exercise and Sport Science Reviews 30:32-38 (2002).
• Raikova, R.T. and Prilutsky, B.I. Sensitivity of predicted muscle forces to parameters of the optimization-based human leg model revealed by analytical and numerical analyses. J. Biomechanics 34: 1243-1255 (2001).
• Gregor, R.J., Smith, J.L., Smith, D.W., Oliver, A. and Prilutsky, B.I. Hindlimb kinetics and neural control during slope walking in the cat: unexpected findings. J. Applied Biomechanics 17: 277-286 (2001).
• Prilutsky B.I. Eccentric muscle action in sport and exercise. In Encyclopedia of Sports Medicine. Biomechanics in Sport (Ed. Zatsiorsky V.M.), pp. 56-86. Oxford, UK, Blackwell Science Ltd. (2000).
• Prilutsky, B. I. Coordination of two- and one-joint muscles: functional consequences and implications for motor control (target article). Motor Control 4:1-44 (2000).
• Prilutsky, B. I. and Gregor R. J. Analysis of muscle coordination strategies in cycling. IEEE Transactions on Rehabilitation Engineering 8: 362-370 (2000).
• Prilutsky, B. I. and Gregor R. J. Swing- and support-related muscle actions differentially trigger human walk-run and run-walk transitions. Journal of Experimental Biology 204: 2277-2287 (2000).