# Trunk Acceleration Asymmetries in Transfemoral and Transtibial Amputee Runners

Mohammad Krombi, Delphine Chadefaux, Christophe Sauret, Thoreux Patricia

► To cite this version:

Mohammad Krombi, Delphine Chadefaux, Christophe Sauret, Thoreux Patricia. Trunk Acceleration Asymmetries in Transfemoral and Transtibial Amputee Runners. Multidisciplinary Biomechanics Journal, 2025, 50th congress of the.., 10.46298/mbj.16226. hal-05191780v2

HAL Id: hal-05191780

https://hal.science/hal-05191780v2

Submitted on 23 Oct 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Trunk Acceleration Asymmetries in Transfemoral and Transtibial Amputee Runners

Mohammad Krombi<sup>a*</sup>, Delphine Chadefaux<sup>a</sup>, Christophe Sauret<sup>a, b</sup>, Patricia Thoreux<sup>a, c</sup>

<sup>a</sup> Arts et Métiers Institute of Technology, EPF Engineering School, Université Sorbonne Paris Nord, IBHGC-Institut de Biomécanique Humaine Georges Charpak, F-75013 Paris, France

<sup>b</sup> Centre d'Etudes et de Recherche sur l'Appareillage des Handicapés, Institution Nationale des Invalides, F-94000 Paris, France

<sup>c</sup> Hôpital Hôtel Dieu, AP-HP, F-75004 Paris, France

* Corresponding author: mohammad.krombi1@univ-paris13.fr

Received date: 06/04/2025

Accepted date: 27/06/2025

Publication date: 27/10/2025

**Keywords:** trunk acceleration, prosthetic running, gait asymmetry, lower-limb amputees

© 2025 The Authors

Licence CC-BY 4.0

Published by Société de Biomécanique

## 1. Introduction

Regular physical activity, such as running, is recommended to improve the overall quality of life in lower-limb amputees. However, engaging in such dynamic activities requires the use of running-specific prostheses. Prolonged use of daily-use prostheses for running can increase the risk of developing hip osteoarthritis (Sepp et al., 2021).

Biomechanical studies of prosthetic running have consistently reported significant asymmetries between the prosthetic limb (PL) and the non-prosthetic limb (NPL). These asymmetries have been predominantly investigated at the level of the lower limbs. To date, little attention has been given to the adaptations occurring at the level of the trunk during running with a prosthesis. The trunk, however, plays a fundamental role in locomotion. Trunk accelerations, which reflect underlying kinematic strategies and help maintain postural stability (Lindsay et al., 2014). In particular, acceleration in the anteroposterior (AP) direction has been shown to offer valuable insights into movement efficiency and potential injury risk (Schütte et al., 2015).

The aim of the present study is to analyze anteroposterior trunk acceleration in novice runners with transfemoral (TF) and transtibial (TT) amputations, as a first step toward understanding compensatory adaptations during prosthetic running.

## 2. Methods

Four recreational runners (1F, 3M; 34±11 y, 171±9 cm, 64±5 kg) participated, including two TT and two TF

amputees, all experienced in treadmill running at a comfortable speed of 8-9 km/h. Each participant used their own prosthesis throughout the trials (1 Ossur Flexi-Run, 1 Hopper, 2 Ottobock sprinter 1E90 + 3S80 knee). Following a warm-up period, participants completed progressive treadmill running trials at speeds ranging from 6 to 12 km/h. At each speed, two 30 second trials were collected.

Kinematic data were recorded using a Vicon® optoelectronic system (100 Hz) and reflective markers placed following ISB recommendations (Wu et al., 2005).

Data were initially processed in Vicon Nexus (v2.12.1), and further analysis of AP trunk acceleration was carried out in MATLAB (R2020a, MathWorks®). An asymmetry index (ASI) was computed to quantify differences between the PL and NPL, using the following formula:

$$ASI = \frac{NPL + PL}{0,5(NPL + PL)} \cdot 100\%$$

## 3. Results and discussion

Three out of four participants completed trials at all running speeds, with an average of 88 ± 9 gait cycles recorded per speed. Figure 1 illustrates an example of mean AP trunk acceleration over one normalized running cycle of the PL, at two different speeds.

When focusing on the stance phase (38% ± 4%), two distinct peaks in AP acceleration can be identified. The first positive peak occurs during the early stance and
corresponds to the braking phase. This peak reflects the deceleration of the trunk as the runner absorbs the impact following ground contact. This acceleration represents the ability of the runner to attenuate ground reaction forces and maintain postural control.

Our results indicate that this braking peak was higher in the TT participants compared to the TF participants (Table 1). However, when analyzing this peak across limbs, particularly in TF runners, we observed that the NPL consistently generated much higher braking accelerations compared to the PL. This was especially evidenced for Subject 2, where the ASI between limbs exceeded 100%, suggesting a marked compensatory strategy from the NPL. In contrast, Subject 1 exhibited lower asymmetry. This participant had a longer residual limb (Gritti-Stokes amputation) and more intact sub-pelvic muscles, contributing to a more efficient braking phase, allowing better prosthetic control and reducing the need for over-compensation. Such a compensation was not observed in the two TT participants, who demonstrated more symmetrical braking peak.

<table><caption>**Table 1.** Braking peak of AP trunk acceleration at two running speeds (6 and 10 km/h), and corresponding ASI.</caption><thead><tr><th>Speed</th><th>6 km/h<br>(m/s²)</th><th>ASI (%)</th><th>10 km/h<br>(m/s²)</th><th>ASI (%)</th></tr></thead><tbody><tr><td>TF1_PL</td><td>1,4 ± 0,3</td><td rowspan="4">35,2</td><td>1,6 ± 0,1</td><td rowspan="4">40,3</td></tr><tr><td>TF1_NPL</td><td>2,0 ± 0,3</td><td>2,4 ± 0,7</td></tr><tr><td>TF2_PL</td><td>0,5 ± 0,2</td><td>0,6 ± 0,1</td></tr><tr><td>TF2_NPL</td><td>2,2 ± 1,4</td><td>1,8 ± 1,1</td></tr><tr><td>TT3_PL</td><td>2,4 ± 0,5</td><td rowspan="3">6</td><td>2,5 ± 0,4</td><td rowspan="3">13,7</td></tr><tr><td>TT3_NPL</td><td>2,5 ± 0,3</td><td>2,8 ± 0,1</td></tr><tr><td>TT4_PL</td><td>1,7 ± 0,5</td><td>2,1 ± 0,2</td></tr><tr><td>TT4_NPL</td><td>2,6 ± 0,2</td><td>30,8</td><td>2,5 ± 0,1</td><td>16</td></tr></tbody></table>

This discrepancy may be linked to the absence of knee flexion during the stance phase in TF runners, which may be explained by the mechanical limitations of TF prostheses, where the absence of active knee control during this stance phase limits the shock absorption capabilities of the prosthesis side.

These asymmetries in the braking response of trunk acceleration have been reported during walking in TF amputees (Tura et al., 2010). When compared to non-amputee individuals, TF amputees exhibit

<figure><img src="image_2.png" /><figcaption>**Figure 1.** Mean AP trunk acceleration at: 6 km/h (solid lines) and 10 km/h (dotted lines). Top: TF amputees; bottom: TT amputees.</figcaption></figure>

differences in the amplitude and stability of trunk acceleration during walking (Lamoth et al., 2010).

Considering that trunk accelerations are influenced by the ground reaction forces transmitted by the lower limbs, these results open up prospects for the in situ assessment of asymmetries using wearable sensors, enabling trainers to optimize performance and reduce compensations.

## 4. Conclusions

Those preliminary results highlight important anteroposterior trunk acceleration asymmetries between prosthetic and non-prosthetic limbs, particularly in transfemoral amputees. The observed overcompensation by the NPL may increase injury risk over time. These findings support further investigation of trunk dynamics in amputee running, and open perspectives for biomechanical monitoring in the field using wearable sensors.

## References

* Lamoth, C. J. C., Ainsworth, E., Polomski, W., & Houdijk, H. (2010). Variability and stability analysis of walking of transfemoral amputees. *Medical*
*Engineering & Physics*, 32(9), Article 9. https://doi.org/10.1016/j.medengphy.2010.07.001

Lindsay, T. R., Noakes, T. D., & McGregor, S. J. (2014). Effect of treadmill versus overground running on the structure of variability of stride timing. *Perceptual and Motor Skills*, *118*(2), Article 2. https://doi.org/10.2466/30.26.PMS.118k18w8

Schütte, K. H., Maas, E. A., Exadaktylos, V., Berckmans, D., Venter, R. E., & Vanwanseele, B. (2015). Wireless tri-axial trunk accelerometry detects deviations in dynamic center of mass motion due to running-induced fatigue. *PLOS ONE*, *10*(10), e0141957. https://doi.org/10.1371/journal.pone.0141957

Sepp, L. A., Baum, B. S., Nelson-Wong, E., & Silverman, A. K. (2021). Hip joint contact loading and muscle forces during running with a transtibial amputation. *Journal of Biomechanical Engineering*, *143*(3), Article 3. https://doi.org/10.1115/1.4049227

Tura, A., Raggi, M., Rocchi, L., Cutti, A. G., & Chiari, L. (2010). Gait symmetry and regularity in transfemoral amputees assessed by trunk accelerations. *Journal of NeuroEngineering and Rehabilitation*, *7*(1), 4. https://doi.org/10.1186/1743-0003-7-4

Wu, G., van der Helm, F. C. T., (DirkJan) Veeger, H. E. J., Makhsous, M., Van Roy, P., Anglin, C., Nagels, J., Karduna, A. R., McQuade, K., Wang, X., Werner, F. W., & Buchholz, B. (2005). ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion—Part II: Shoulder, elbow, wrist and hand. *Journal of Biomechanics*, *38*(5), 981–992. https://doi.org/10.1016/j.jbiomech.2004.05.042