Na Jin Seo, Ph.D.

(414) 229-2906
University Services and Research 201D
Assistant Professor
Industrial And Manufacturing Engr

Dr. Seo has spent more than a decade in the developing new assistive and therapeutic hand devices. Her research aims to evaluate the neurophysiologic effects these devices have in the brain and musculoskeletal system. Her most recent research addresses how remote vibrotactile noise improves light touch sensation in stroke survivors’ fingertips.  She is also active as a high school mentor and robotics coach.


  • Post-doc, Rehabilitation Institute of Chicago, Northwestern University, Chicago, IL, 2009
  • Ph.D., Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan, 2007
  • M.S., Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan, 2005
  • B.S., Mechanical Engineering, POSTECH, Pohang, South Korea, 2002

Research Focus:

  • Biomechanics
  • Rehabilitation
  • Neuromechanics
  • Ergonomics

Honors and Awards:

  • 2013 Hugh Kelly Research Fellowship Award, South Africa
  • 2013 Millionaires’ Club, University of Wisconsin-Milwaukee
  • 2012 Graduate School / University of Wisconsin-Milwaukee Foundation Research Award
  • 2012 University of Wisconsin Libraries Research Fellows
  • 2011 Distinguished Fellowship Award by the National Institute on Disability and Rehabilitation Research
  • 2010 UWM Research Fellows Awards
  • 2010 Recipient of the Dr Judith Stitt Women Faculty Scholar Grant by the Wisconsin Women's Health Foundation
  • 2001 Winner, Research Competition, “Mechanical design of an automatic toothbrush for people without hands or people with upper limb paresis,” South Korea
  • 2000 2nd place, International Intelligent Robot Contest, “Development of an intelligent robot controlled by eye and facial movements,” South Korea
  • 1998 Silver medal, National Invention Competition, “User-friendly one-size-fits-all battery socket,” Korea


  • Hur P, Wan Y-H, Seo NJ. Investigating the role of vibrotactile noise in early muscle reaction to perturbation, IEEE Transactions on Biomedical Engineering, in Press, 2013.
  • Slota GP, Enders LR, Seo NJ. Improvement of hand function using different surfaces and identification of difficult movement post stroke in the Box and Block Test, Applied Ergonomics, in Press, 2013.
  • Enders LR, Hur P, Johnson MJ, and Seo NJ. Remote vibrotactile noise improves light touch sensation in stroke survivors’ fingertips via stochastic resonance, Journal of NeuroEngineering and Rehabilitation, 10:105, 2013.
  • Hur P, Motawar BR, Seo NJ, Role of glove use in the biomechanical response to handle perturbation, Journal of Electromyography and Kinesiology, in Press, 2013
  • Seo NJ. Involuntary contralateral hand activity during unilateral grip exertion in persons with chronic stroke. Journal of Hand Therapy, 26 (3) 272-7, 2013.
  • Park J, Seo NJ, Son J, Kim W, Cheong J, Postural variation of hand precision grips by object size, Journal of Mechanical Science and Technology, in Press, 2013
  • Motawar BR, Hur P, Stinear JW, Seo NJ. Contribution of corticomotor inhibition in voluntary muscle relaxation, Experimental Brain Research, 221 (3) 299-308, 2012.
  • Seo NJ, Enders LR. Hand grip function assessed by the Box and Block Test (BBT) is affected by object surfaces, Journal of Hand Therapy, 25 (4) 397-405, 2012.
  • Hur P, Motawar BR, Seo NJ. Hand Breakaway Strength Model - Effects of glove use and handle shapes on a person’s hand strength to hold onto handles to prevent fall from elevation, Journal of Biomechanics, 45, 958-64, 2012.
  • Shim JK, Karol S, Kim Y-S, Seo NJ, Kim YH, Kim Y, Yoon B. Tactile feedback plays a critical role in maximum finger force production, Journal of Biomechanics, 45 (3) 415-20, 2012.
  • Seo NJ, Fischer HC, Bogey RA, Rymer WZ, Kamper DG. Effect of a serotonin antagonist on delay in grip muscle relaxation for persons with chronic hemiparetic stroke, Clinical Neurophysiology, 122, 796-802, 2011.
  • Seo NJ, Shim JK, Engel AK, Enders LR. Grip surface affects maximum pinch force, Human Factors, 53 (6) 740-8, 2011.
  • Seo NJ, Sindhu BS, Shechtman O. Influence of pain associated with musculoskeletal disorders on grip force timing, Journal of Hand Therapy, 24 (4) 335-43, 2011.
  • Seo NJ, Fischer HC, Bogey RA, Rymer WZ, Kamper DG. Use of visual force feedback to improve digit force direction during pinch grip in persons with stroke - A pilot study, Archives of Physical Medicine & Rehabilitation, 92 (1) 24-30, 2011.
  • Enders LR, Seo NJ. Phalanx force magnitude and trajectory deviation increased during power grip with an increased coefficient of friction at the hand-object interface, Journal of Biomechanics, 44 (8) 1447-53, 2011.
  • Seo NJ, Armstrong TJ. Effect of elliptic handle shape on grasping strategies, grip force distribution, and twisting ability, Ergonomics, 54 (10) 961-70, 2011.
  • Seo NJ, Rymer WZ, Kamper DG. Altered Digit Force Direction during Pinch Grip Following Stroke. Experimental Brain Research, 202 (4) 891-901, 2010.
  • Seo NJ, Armstrong, T.J., Young, J.G. Effects of Handle Orientation, Gloves, Handle Friction and Elbow Posture on Maximum Horizontal Pull and Push Forces. Ergonomics, 53 (1) 92-101, 2010.
  • Seo NJ, Rymer WZ, Kamper DG. Delays in Grip Initiation and Termination in Persons with Stroke: Effects of Arm Support and Active Muscle Stretch Exercise, Journal of Neurophysiology, 101, 3108-3115, 2009.
  • Seo NJ, Armstrong TJ. Friction Coefficients in a Longitudinal Direction between the Finger Pad and Selected Materials for Different Normal Forces and Curvatures. Ergonomics, 52 (5) 609-616, 2009.
  • Seo NJ. Dependence of Safety Margins in Grip Force on Isometric Push Force Levels in Lateral Pinch. Ergonomics, 52 (7) 840-847, 2009.
  • Seo NJ, Armstrong TJ. Biomechanical Analysis for Handle Stability during Maximum Push and Pull Exertions. Ergonomics, 52 (12) 1568-1575, 2009.
  • Seo NJ, Armstrong TJ, Drinkaus P. A Comparison of Two Methods of Measuring Static Coefficient of Friction at Low Normal Forces: A Pilot Study. Ergonomics, 52 (1) 121-135, 2009.
  • Seo NJ, Armstrong TJ, Chaffin DB, Ashton-Miller JA. Inward Torque and High-Friction Handles Can Reduce Required Muscle Efforts for Torque Generation. Human Factors, 50 (1) 37-48, 2008.
  • Seo NJ, Armstrong TJ. Investigation of Grip Force, Normal Force, Contact Area, Hand Size, and Handle Size for Cylindrical Handles. Human Factors, 50 (5) 734-744, 2008.
  • Seo NJ, Armstrong TJ, Chaffin DB, Ashton-Miller JA. The Effect of Handle Friction and Inward or Outward Torque on Maximum Axial Push Force. Human Factors, 50 (2) 227-236, 2008.
  • Seo NJ, Armstrong TJ, Ashton-Miller JA, Chaffin DB. Wrist Strength is Dependent on Simultaneous Power Grip Intensity. Ergonomics, 51 (10) 1594-1605, 2008.
  • Seo NJ, Kamper DG. Effect of Arm Posture, Arm Support, and Muscle Stretch on Sustained Finger Flexor Activity Following Stroke. Proceedings of the 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. Vancouver, Canada, 2008.
  • Seo NJ, Armstrong TJ, Ashton-Miller JA, Chaffin DB. The Effect of Torque Direction and Cylindrical Handle Diameter on the Coupling between the Hand and a Cylindrical Handle. Journal of Biomechanics, 40, 3236-3243, 2007.

Community Involvement:

  • Participant in the Wisconsin Women's Health Foundation's "Paying It Forward for the Health of Wisconsin Women" initiative (2014).
  • Mentor/coach for the CTSI Pilot Award in 2014-2015.
  • Advisor for the Deer Creek Intermediate School Robotics Club.
  • Served as a judge for the “Wisconsin YES!” student business plan contest for 12th grade students’ business plans.
  • Served as a judge for the General Electric (GE) Ergo Cup in 2010.
  • Participated as a career mentor for high school students from low-income families.