Exploring the Virtual Pivot Point in Unilateral Transfemoral Amputee Locomotion: Implications for Prosthetic Development
Mohseni O, Ebrahimian S, Firouzi V, Khosrotabar M, Kupnik M, Sharbafi MA, Seyfarth A (2025)
Publication Type: Conference contribution
Publication year: 2025
Journal
Publisher: Institute of Electrical and Electronics Engineers Inc.
Pages Range: 8254-8260
Conference Proceedings Title: IEEE International Conference on Intelligent Robots and Systems
Event location: Hangzhou, CHN
ISBN: 9798331543938
DOI: 10.1109/IROS60139.2025.11246205
Abstract
The virtual pivot point (VPP), a theoretical convergence point of ground reaction forces during gait, has gained attention for its potential to uncover underlying locomotor control strategies. Here, we present the first investigation of VPP in individuals with unilateral above-knee amputation, using a publicly available dataset of 18 participants. Subjects were categorized into K2 (walking speeds 0.4-0.8m/s) and K3 (0.6-1.4m/s) functional levels. Our findings show that both groups demonstrate high sagittal-plane VPP quality, comparable to that of healthy individuals, with R2 > 95%, indicating a strong relationship between VPP formation and sagittal plane dynamics. Conversely, in the frontal plane, VPP analysis reveals greater variability and lower quality, indicating the absence of a well-defined pivot during gait. Notably, frontal-plane VPP quality deteriorates with increasing walking speed, particularly in K3 ambulators. While this speed-dependency is observed in healthy individuals as well, the rate of decline is significantly steeper in amputees. Additionally, spatial analysis of VPP positions reveals a consistent elevation of the amputated leg's VPP compared to the intact leg. These findings emphasize the importance of frontal plane dynamics in amputee gait and suggest improvements in prosthetic design to enhance control and promote more symmetrical, natural gait.
Involved external institutions
Germany (DE)
Finland (FI)How to cite
APA:
Mohseni, O., Ebrahimian, S., Firouzi, V., Khosrotabar, M., Kupnik, M., Sharbafi, M.A., & Seyfarth, A. (2025). Exploring the Virtual Pivot Point in Unilateral Transfemoral Amputee Locomotion: Implications for Prosthetic Development. In Christian Laugier, Alessandro Renzaglia, Nikolay Atanasov, Stan Birchfield, Grzegorz Cielniak, Leonardo De Mattos, Laura Fiorini, Philippe Giguere, Kenji Hashimoto, Javier Ibanez-Guzman, Tetsushi Kamegawa, Jinoh Lee, Giuseppe Loianno, Kevin Luck, Hisataka Maruyama, Philippe Martinet, Hadi Moradi, Urbano Nunes, Julien Pettre, Alberto Pretto, Tommaso Ranzani, Arne Ronnau, Silvia Rossi, Elliott Rouse, Fabio Ruggiero, Olivier Simonin, Danwei Wang, Ming Yang, Eiichi Yoshida, Huijing Zhao (Eds.), IEEE International Conference on Intelligent Robots and Systems (pp. 8254-8260). Hangzhou, CHN: Institute of Electrical and Electronics Engineers Inc..
MLA:
Mohseni, Omid, et al. "Exploring the Virtual Pivot Point in Unilateral Transfemoral Amputee Locomotion: Implications for Prosthetic Development." Proceedings of the 2025 IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2025, Hangzhou, CHN Ed. Christian Laugier, Alessandro Renzaglia, Nikolay Atanasov, Stan Birchfield, Grzegorz Cielniak, Leonardo De Mattos, Laura Fiorini, Philippe Giguere, Kenji Hashimoto, Javier Ibanez-Guzman, Tetsushi Kamegawa, Jinoh Lee, Giuseppe Loianno, Kevin Luck, Hisataka Maruyama, Philippe Martinet, Hadi Moradi, Urbano Nunes, Julien Pettre, Alberto Pretto, Tommaso Ranzani, Arne Ronnau, Silvia Rossi, Elliott Rouse, Fabio Ruggiero, Olivier Simonin, Danwei Wang, Ming Yang, Eiichi Yoshida, Huijing Zhao, Institute of Electrical and Electronics Engineers Inc., 2025. 8254-8260.
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