Development of a System for Measuring the Three-Axis Pedal Force in Cycling and Its Applications

For cycling, the analysis of the pedal force is one of the
important factors in the study of exercise ability assessment and
overuse injuries. In past studies, a two-axis measurement sensor was
used at the sagittal plane to measure the force only in the anterior,
posterior, and vertical directions and to analyze the loss of force and
the injury on the frontal plane due to the forces in the right and left
directions. In this study, which is a basic study on diverse analyses of
the pedal force that consider the forces on the sagittal plane and the
frontal plane, a three-axis pedal force measurement sensor was
developed to measure the anterior-posterior (Fx), medio-lateral (Fz),
and vertical (Fy) forces. The sensor was fabricated with a size and
shape similar to those of the general flat pedal, and had a 550g weight
that allowed smooth pedaling. Its measurement range was ±1000 N for
Fx and Fz and ±2000 N for Fy, and its non-linearity, hysteresis, and
repeatability were approximately 0.5%. The data were sampled at
1000 Hz using a signal collector. To use the developed sensor, the
pedaling efficiency (index of efficiency, IE) and the range of left and
right (medio-lateral, ML) forces were measured with two seat heights
(low and high). The results of the measurement showed that the IE was
higher and the force range in the ML direction was lower with the high
position than with the low position. The developed measurement
sensor and its application results will be useful in understanding and
explaining the complicated pedaling technique, and will enable
diverse kinematic analyses of the pedal force on the sagittal plane and
the frontal plane.

• Joo-Hack Lee
• Jin-Seung Choi
• Dong-Won Kang
• Jeong-Woo Seo
• Ju-Young Kim
• Dae-Hyeok Kim
• Seung-Tae Yang
• Gye-Rae Tack

• Cycling
• Index of effectiveness
• Pedal force.

[1] C. J. Hansson, G. E. Caldwell, and R. E. van Emmerik, “Changes in
muscle and joint coordination in learning to direct forces,” Human
movement science, vol. 27, no. 4, 2008, pp. 590-609.
[2] C. T. Candotti, J. Ribeiro, D. P. Soares, A. R. De Oliveira, J. F. Loss and
A. C. S. Guimarães, “Effective force and economy of triathletes and
cyclists,” Sports Biomechanics, vol. 6, no.1, 2007, pp. 31-43.
[3] J. C. Holmes, A. L. Pruitt, and N. J. Whalen, “Lower extremity overuse in
bicycling,” Clinics in sports medicine, vol. 13, no.1, 1994, pp.187-205.
[4] J. P. Broker, R. J. Gregor, “A dual piezoelectric element force pedal for
kinetic analysis of cycling,” International Journal of Sports Biomechanics,
vol. 6, no.4, 1990, pp. 394-403.
[5] M. A. Lafortune, P. R. Cavanagh, Effectiveness and efficiency during
bicycle riding. champaign , Il: Human Kinetics, 1983, pp.928-936.
[6] M. O. Ericson, R. Nisell, and J. Ekholm, “Varus and valgus loads on the
knee joint during ergometer cycling,” Scand J Sports Sci, vol. 6, 1984, pp.
39-45.
[7] P. Ruby, M. L. Hull, and D. Hawkins, “Three-dimensional knee joint
loading during seated cycling,” Journal of biomechanics, vol. 25, no.1,
1992, pp. 41-53.
[8] R. Bini, “Effects of saddle position on pedaling technique and methods to
assess pedaling kinetics and kinematics of cyclists and triathletes,” Ph.D.
Dissertation, Auckland University of technology, 2011.
[9] R. Bini, F. Diefenthaler, F. Carpes and C. Billi mota, “External work
bilateral symmetry during incremental cycling exercise,” in Proc. 25th
International Symposium on Biomechanics in Sports ,Ouro Preto-Brazil,
2007, pp. 23-27.
[10] R. R. Bini, M. Rossato, F. Diefenthaeler, F. P. Carpes, D. C. Dos reis and
A. R. P. Moro, “Pedaling cadence effects on joint mechanical work during
cycling,” Isokinetics and Exercise Science, vol. 18, no. 1, 2010, pp. 7-13.
[11] R. R. Bini, P. A. Hume, J. Croft, A. E. Kilding, “Pedal force effectiveness
in cycling: a review of constraints and training effects,” Journal of
Science and Cycling, vol. 2, no. 1, 2013, pp. 11-24.
[12] S. Dorel, J. M. Drouet, F. Hug, P. M. Lepretre, “New instrumented pedals
to quantify 2D forces at the shoe-pedal interface in ecological conditions:
preliminary study in elite track cyclists,” Computer Methods in
Biomechanics and Biomedical Engineering, vol. 11, no. S1, 2008, pp.
89-90.
[13] T. Hattori, “Body up–down acceleration in kinematic gait analysis in
comparison with the vertical ground reaction force,” Bio-medical
materials and engineering, vol. 8, no. 3, 1998, pp. 145-154.
[14] T. Korff, L. M. Romer, I. Mayhew and J. C. Martin, “Effect of pedaling
technique on mechanical effectiveness and efficiency in cyclists,”
Medicine and science in sports and exercise, vol. 39, no. 6, 2007,
pp.991-995.
[15] W. W. Peveler, “Effects of saddle height on economy in cycling,” Journal
of Strength and Conditioning Research, vol. 22, no. 4, 2008,
pp.1355-1359.
[16] W. W. Peveler and J. M. Green, “Effects of saddle height on economy and
anaerobic power in well-trained cyclists,” Journal of Strength and
Conditioning Research, vol. 25, no. 3, 2011, pp. 629-633.