MR 회전형 브레이크를 적용한 자전거 에르고미터의 주행 특성

Pedaling Characteristics of Cycle Ergometer Using the MR Rotary Brake

  • 윤영일 (전북대학교 헬스케어공학과) ;
  • 권대규 (전북대학교 바이오메디컬공학부) ;
  • 김동욱 (전북대학교 바이오메디컬공학부) ;
  • 김정자 (전북대학교 바이오메디컬공학부) ;
  • 김남균 (전북대학교 바이오메디컬공학부)
  • 발행 : 2008.09.01


A new cycle ergometer using a Magneto-Rheological (MR) rotary brake system has been developed for rehabilitation of hemiplegia patients to reduce uneven pedaling characteristics. For this purpose, a control method to adjust the resistance of the MR rotary brake in real time based on the magnitude of the muscular force exerted by the subject has been devised so that the mechanical resistance to the pedaling can be minimized when the affected leg was engaged for pedaling. A series of experiments were carried out with and without the engagement of this real-time control mode of MR rotary brake at different pedaling rate to find out the effect of the real-time control mode. The characteristics of the pedaling for these specific conditions were analyzed based on the variations in angular velocities of the pedal unit. The results showed that the variations in the angular velocities were decreased by 42.9% with the control mode. The asymmetry of pedaling between dominant and non-dominant leg was 19.63% in non-control mode and 1.97% in the control mode. The characteristics of electromyography(EMG) in the lower limbs were also measured. The observation showed that Integrated EMG(IEMG) reduced with the control mode. Therefore, the new bicycle system using MR brake with the real time control of mechanical resistance was found to be effective in recovering the normal pedaling pattern by reducing unbalanced pedaling characteristics caused by disparity of muscular strength between affected and unaffected leg.


  1. H. Cohen, C. A. Blatchly, L. L. Combash, "A study of the clinical test of sensory interaction and balance", Physical Therphy, pp. 346-354, 1993
  2. M. Hull, M. Jorge, "A method for biomechanical analysis of bicycling.", J Biomech., pp.631-644, 1985
  3. J. B. Chae, B. J. Kim, S. S. Bae, "A study on the control factors of posture and balance", J Kor. Soci. Phys. Ther., pp. 421-431, 2001
  4. M. Ericson, "On the biomechanics of cycling. A study of joint and muscle load during exercise on the bicycle ergometer.", Scand J Rehabil Med Suppl.., pp.1-43, 1986
  5. C. G. Song, J. Y. Kim, N. G. Kim, "A new postural balance control system for rehabilitation training based on virtual cycling", IEEE Trans. Rehabi. Eng, pp. 200-207, 2004
  6. J. C. Wall, G. I. Turnbull, "Gait asymmetries in residual hemiplegia". Arch. Phys. Med. Rehabil., pp. 550-553, 1986
  7. M. Jorge, M. Hull, "Analysis of EMG measurements during bicycle pedalling", J Biomech., pp.683-694, 1986