Effects of step frequency during running on the magnitude and symmetry of ground reaction forces in individuals with a transfemoral amputation

Toshiki Kobayashi; Mark W P Koh; Mingyu Hu; Hiroto Murata; Genki Hisano; Daisuke Ichimura; Hiroaki Hobara

doi:10.1186/s12984-022-01012-8

Effects of step frequency during running on the magnitude and symmetry of ground reaction forces in individuals with a transfemoral amputation

J Neuroeng Rehabil. 2022 Mar 23;19(1):33. doi: 10.1186/s12984-022-01012-8.

Authors

Toshiki Kobayashi¹, Mark W P Koh¹, Mingyu Hu¹, Hiroto Murata^{2

3}, Genki Hisano^{2

4

5}, Daisuke Ichimura², Hiroaki Hobara⁶

Affiliations

¹ Department of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
² Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Waterfront 3F, 2-3-26, Aomi, Koto-ku, Tokyo, 135-0064, Japan.
³ Department of Mechanical Engineering, Tokyo University of Science, Chiba, Japan.
⁴ Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo, Japan.
⁵ Research Fellow of Japan Society for the Promotion of Science (JSPS), Tokyo, Japan.
⁶ Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Waterfront 3F, 2-3-26, Aomi, Koto-ku, Tokyo, 135-0064, Japan. hobara-hiroaki@aist.go.jp.

Abstract

Background: Individuals with unilateral transfemoral amputation are prone to developing health conditions such as knee osteoarthritis, caused by additional loading on the intact limb. Such individuals who can run again may be at higher risk due to higher ground reaction forces (GRFs) as well as asymmetric gait patterns. The two aims of this study were to investigate manipulating step frequency as a method to reduce GRFs and its effect on asymmetric gait patterns in individuals with unilateral transfemoral amputation while running.

Methods: This is a cross-sectional study. Nine experienced track and field athletes with unilateral transfemoral amputation were recruited for this study. After calculation of each participant's preferred step frequency, each individual ran on an instrumented treadmill for 20 s at nine different metronome frequencies ranging from - 20% to + 20% of the preferred frequency in increments of 5% with the help of a metronome. From the data collected, spatiotemporal parameters, three components of peak GRFs, and the components of GRF impulses were computed. The asymmetry ratio of all parameters was also calculated. Statistical analyses of all data were conducted with appropriate tools based on normality analysis to investigate the main effects of step frequency. For parameters with significant main effects, linear regression analyses were further conducted for each limb.

Results: Significant main effects of step frequency were found in multiple parameters (P < 0.01). Both peak GRF and GRF impulse parameters that demonstrated significant main effects tended towards decreasing magnitude with increasing step frequency. Peak vertical GRF in particular demonstrated the most symmetric values between the limbs from - 5% to 0% metronome frequency. All parameters that demonstrated significant effects in asymmetry ratio became more asymmetric with increasing step frequency.

Conclusions: For runners with a unilateral transfemoral amputation, increasing step frequency is a viable method to decrease the magnitude of GRFs. However, with the increase of step frequency, further asymmetry in gait is observed. The relationships between step frequency, GRFs, and the asymmetry ratio in gait may provide insight into the training of runners with unilateral transfemoral amputation for the prevention of injury.

Keywords: Amputee; Gait; Ground reaction forces; Kinetics; Running; Running-specific prosthesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amputation, Surgical
Amputees*
Artificial Limbs*
Biomechanical Phenomena
Cross-Sectional Studies
Gait
Humans
Running*