Preprint / Version 2

Inter-joint coordination to minimize angular momentum reduction in backward somersault dismounts at parallel bars


  • Hiro Hirabayashi Department of Life Sciences (Sports Sciences), Graduate School of Arts and Sciences, University of Tokyo
  • Daisuke Takeshita Department of Life Sciences (Sports Sciences), Graduate School of Arts and Sciences, University of Tokyo



Gymnastics, parallel bars, optimiziations, somersault, induced acceleration analysis


Backward somersault dismounts at parallel bars in artistic gymnastics are considered fundamental movements for other advanced skills, such as double backward tucked and piked somersaults. It has been previously discussed that angular momentum reduction around the center of mass occurs right before takeoff. However, such angular momentum reduction would decrease the number of rotations during somersaults, making it difficult for a gymnast to perform higher-valued dismounts. We hypothesized that avoiding this angular momentum reduction may be essential for enabling a large number of rotations and tested this hypothesis based on computer-based optimizations. We first determined the best stunt and observed hip flexion in the middle of the stunt, which is an unlikely movement for gymnasts. To avoid conclusions with applications only limited to unusual stunts with such hip flexion, we performed yet another optimization under additional constraints suppressing hip flexion in the middle of a stunt. In both these optimized stunts, angular momentum reduction was observed, thereby rejecting our hypothesis. However, an induced acceleration analysis of these stunts revealed that wrist and shoulder coordination weakened this angular momentum reduction, suggesting the importance of inter-joint coordination for better performance in backward somersault dismounts.


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Ae, M., Tang, H., Yokoi, T., 1992. Estimation of inertia properties of the body segments in japanese athletes. Biomechanisms 11, 23–33.

Hirashima, M., 2011. Induced acceleration analysis of three-dimensional multi-joint movements and its application to sports movements. In: Klika, V., Theoretical Biomechanics, IntechOpen, Rijeka, chapter 14.

Koike, S., Ishikawa, T., Willmott, A. P., Bezodis, N. E., 2019. Direct and indirect effects of joint torque inputs during an induced speed analysis of a swinging motion. Journal of biomechanics 86, 8–16.

Linge, S., Hallingstad, O., Solberg, F., 2006. Modelling the parallel bars in men ’s artistic gymnastics. Human movement science 25(2), 221-237.

Liu, M. Q., Anderson, F. C., Pandy, M. G., Delp, S. L., 2006. Muscles that support the body also modulate forward progression during walking. Journal of biomechanics 39(14), 2623–2630.

Millard, M., Emonds, A. L., Harant, M., Mombaur, K., 2019. A reduced muscle model and planar musculoskeletal model fit for the simulation of whole-body movements. Journal of biomechanics 89, 11–20.

Prassas, S., Papadopoulos, C., 2001. Mechanics of forward support swing skills on the parallel bars. Journal of Human Movement Studies 40, 335–350.

Zajac, F. E., Neptune, R. R., Kautz, S. A., 2002. Biomechanics and muscle coordination of human walking: Part i: Introduction to concepts, power transfer, dynamics and simulations. Gait & posture 16(3), 215–232.



2022-09-11 — Updated on 2022-11-06