Advertisement

Sports Engineering

, Volume 6, Issue 1, pp 21–30 | Cite as

Estimation of reaction forces in high bar swinging

  • D. G. Kerwin
  • M. J. Hiley
Article

Abstract

Reaction forces experienced by gymnasts swinging on the high bar may be determined indirectly using inverse dynamics analysis or may be measured using strain gauges. The accuracy of inverse dynamics analysis may be poor because of errors in the estimated inertia parameters and in the accelerations obtained from digitized data. On the other hand the use of strain gauges is not always possible in elite competition. This paper presents a method for estimating the reaction forces based on the linear displacements of the bar.

The bar was modelled as a point mass attached to horizontal and vertical linear springs (obeying Hooke’s law) with stiffness coefficients determined from static loading. The stiffness coefficients of the bar were determined with three different tensions in the stabilizing cables of the high bar. A force and video analysis of backward giant circles was performed. Estimates for the reaction forces were obtained by multiplying the bar displacements from the video analysis by the stiffness coefficients determined from the static loadings. Comparisons were made between the estimated reaction forces and the reaction forces recorded using strain gauges attached to the high bar.

Varying the tension in the stabilizing cables of the high bar did not effect the stiffness of the bar. Root mean squared differences between estimated and recorded reaction forces were on average within 99 N for three ‘regular’ and three ‘accelerated’ giant circles. This was less than 3.5% of the range of forces recorded. The bar displacement method was able to estimate the peak reaction forces to within 7% on average, which compares favourably with 24% reported by Gervais (1993) using inverse dynamics.

Keywords

biomechanics gymnastics high bar reaction forces 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Abdel-Aziz, Y.I. & Karara, H. M. (1971)Direct Linear Transformation from Comparator coordinates into Object Space Coordinates in Close-range Photogrammetrey (ASP Symposium on Close-range Photogrammetrey) 1–18. American Society of Photogrammetrey, Falls Church, VA.Google Scholar
  2. Arampatzis, A. & Brüggemann, G.-P. (1999) Mechanical energetic processes during the giant swing exercise before dismounts and flight elements on the high bar and uneven parallel bars.Journal ofBiomechanics,32, 811–820.CrossRefGoogle Scholar
  3. Brüggemann, G.-P., Cheetham, P. J., Alp, Y. & Arampatzis, D. (1994) Approach to a biomechanical profile of dismounts and release-regrasp skills of the high bar.Journal of Applied Biomechanics,10, 291–312.Google Scholar
  4. Continental Sports Ltd, UK (1994)Norm-testing of functional properties of FIG equipment and FIG mats. Continental Sports Ltd, Huddersfield.Google Scholar
  5. Enchun, L. (1989) A study of the technique, principles and characteristics of the one arm giant swing backward.GRASP,7, 94–96.Google Scholar
  6. Fédération Internationale de Gymnastique (2001).Apparatus Norms (Brochure des engins), Measurements, Dimensions and Forms. FIG, Switzerland.Google Scholar
  7. Gervais, P. (1993) Calculation of reaction forces at the hands on the horizontal bar from positional data. In:Proceedings of the XIVth Congress of the International Society of Biomechanics, 468–469. University of South Paris, Paris.Google Scholar
  8. Hiley, M. J. (1998)Mechanics of the Giant Circle on High Bar. PhD thesis, Loughborough University, Loughborough, Leicestershire, UK.Google Scholar
  9. Ishii, K. & Komatsu, T. (1987) Changes of kinetic parameters and forces on the horizontal bar backward giant swing. In:Diagnostics, Treatment and Analysis of Gymnastic Talent (eds T.B. Hoshizaki, J. H. Salmela & B. Petiot), 107–117. Sports Psyche Editions, Montreal.Google Scholar
  10. Kerwin, D. G. (1995) Apex/target high resolution video digitising system. In:Procedings of the Biomechanics Section of the British Association of Sports and Exercise Science (ed. J. Watkins), 1–4. BASES, Glasgow.Google Scholar
  11. Kopp, P.M. & Reid, J. G. (1980) A force torque analysis of giant swings on the horizontal bar.Canadian Journal of Applied Sports Science 5, 98–102.Google Scholar
  12. Neal, R. J., Kippers, V., Plooy, D. & Forwood, M.R. (1995) The influence of hand guards on forces and muscle activity during giant swings on the high bar.Medicine & Science in Sports & Exercise,27, 1550–1556.CrossRefGoogle Scholar
  13. Wood, G.A. & Jennings, L. S. (1979) On the use of spline functions for data smoothing.Journal ofBiomechanics,12, 477–479.CrossRefGoogle Scholar

Copyright information

© isea 2003

Authors and Affiliations

  1. 1.Department of Sport and Exercise ScienceUniversity of BathBathUK
  2. 2.School of Sport & Exercise SciencesLoughborough UniversityLeicestershireUK

Personalised recommendations