A Case Study Approach: Walking Assist Scheme Exploiting Somatic Reflex of a Leg-Paralysis Patient
Kojiro Matsushita, Akihiro Yamakawa, Hiroshi Yokoi,
and Tamio Arai
Department of Precision Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
We propose a walking-assist scheme that exploits residual functions of a hemiplegic patient with a unique case of leg paralysis – involving the somatic reflex that prevented her from raising her left leg, leaving it to drag on the ground instead. She prevented this by pressing a specific spot on her leg with her fingers. We measured electromyographic (EMG) signals and found that although she could not voluntary activate her thigh and tibial muscle, mechanical stimulus activates them. We concluded that her paralysis was a unique somatic reflex of her nerve system and we developed a mechanical stimulator that she used to train her muscles in walking and improved her gait to approach that of an unparalyzed person.
-  F. Mata, R. Sanz, and A. Puente, “Increasing Intelligence in Autonomous Wheelchairs,” Journal of Intelligent and Robotic Systems, 22, pp. 211-232, 1998.
-  A. Rentschler, R. Cooper, B. Blasch, and M. Boninger, “Intelligent walkers for the elderly: Performance and safety testing of VAPAMAID robotic walker,” Journal of Rehabillitation Research & Development, Vol.40, No.5, pp. 423-432, 2003.
-  G. Lacey and K. Dawson-Howe, “The Application of Robotics to a Mobility Aid for the Elderly Blind,” Robotics and Autonomous Systems, No.23, pp. 245-252, 1998.
-  K. Turker, P. Brodin, and T.Miles, “Reflex responses of motor units in human masseter muscle to mechanical stimulation of a tooth,” Experimental Brain Research, Vol.100, No.2, pp. 307-315, 1994.
-  T. Karcnik, T. Watanabe, R. Futami, and N. Hoshimiya, “Wearable data collection system for on-line gait stability analysis,” Neuromodulation, Vol.7, No.3, pp. 223-229, 2004.
-  T. Iwasaki, N. Shiba, H. Matsuse, T. Nago, Y. Umezu, T. Tagawa, K. Nagata, and J. Basford, “Improvement in Knee Extension Strength through Training by Means of Combined Electrical Stimulation and Voluntary Muscle Contraction,” Tohoku J. Exp. Med., Vol.209, pp. 33-40, 2006.
-  H. Matsuse, N. Shiba, Y. Umezu, T. Nago, Y. Tagawa, T. Kakuma, K. Nagata, and J. Basford, “Muscle Training by Means of Combined Electrical Stimulation and Volitional Contraction,” Aviat Space Environ. Med., Vol.77, pp. 581-585, 2006.
-  B. Smith, P. Peckham, M. Keith, and D. Roscoe, “An externally powered, multichannel, implantable stimulator for versatile control of paralyzed muscle,” IEEE Trans. Biomed. Eng., Vol.BME-34, pp. 499-508, 1977.
-  R. Kobetic, R. Triolo, and E. Marsolais, “Muscle selection and walking performance of multichannel FES systems for ambulation in paraplegia,” IEEE Trans. Rehabil. Eng., Vol.5, No.1, pp. 23-29, 1997.
-  A. Hines, P. Crago, G. Chapman, and C. Billian, “Stimulus artifact removal in EMG from muscles adjacent to stimulated muscles,” J. Neurosci. Methods, Vol.64, No.1, pp. 55-62, 1996.
-  I. Cikajlo and T. Bajd, “FES Gait Re-education: The Swing Phase Estimation,” Neuromodulation, Vol.6, No.2, pp. 122-127, 2003.
-  T. Bajd, I. Cikajlo, I. Savrin, R. Erzin, and F. Gider, “FES Rehabilitative Systems for Re-Education of Walking in Incomplete Spinal Cord Injured Persons,” Neuromodulation, Vol.3, No.3, pp. 167-174, 2000.
-  Otto Bock, website,
-  N. Hata and Y. Hori, “Human Walking Assist Control on Level Ground,” IEEE Advanced Motion Control, pp. 340-343, 2006.
-  K. Suzuki, Y. Kawamura, T. Hayashi, T. Sakurai, Y. Hasegawa, and Y. Sankai, “Intension-Based Walking Support for Paraplegia Patient,” IEEE Int. Conf. on Systems, Man and Cybernetics, Vol.3, pp. 2707-2713, Oct. 2005.
-  A. Lundberg, “Multisensory control of spinal reflex pathways,” In: R. Granit and O. Pompeiano (Eds.), Reflex control of posture and movements, Prog. Brain Res., Vol.50, pp. 11-28, 1979.
-  T. Karcnik and A. Kralj, “Stability and energy criteria in healthy and paraplegic subject gait,” Artificial Organs, Vol.21, pp. 191-194, 1997.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.
Copyright© 2007 by Fuji Technology Press Ltd. and Japan Society of Mechanical Engineers. All right reserved.