Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jun 28;13(7):212.
doi: 10.3390/sports13070212.

Effects of Different Moments of Inertia on Neuromuscular Performance in Elite Female Soccer Players During Hip Extension Exercise to Prevent Hamstring Asymmetries and Injuries: A Cross-Sectional Study

Jordi Pumarola  1   2 , Alesander Badiola-Zabala  3 , Mònica Solana-Tramunt  2
Affiliations

Effects of Different Moments of Inertia on Neuromuscular Performance in Elite Female Soccer Players During Hip Extension Exercise to Prevent Hamstring Asymmetries and Injuries: A Cross-Sectional Study

Jordi Pumarola et al. Sports (Basel). .

Abstract

Background: High-intensity actions like accelerations and decelerations, often performed unilaterally, are crucial in elite female football but increase the risk of interlimb asymmetries and injury. Flywheel resistance training enhances eccentric strength, yet limited research has assessed how different inertial loads affect mechanical outputs in unilateral exercises.

Purpose: This study investigated how two inertial loads (0.107 kg·m2 and 0.133 kg·m2) influence power, acceleration, speed, and asymmetry during unilateral hip extensions in elite female footballers.

Methods: Eighteen professional players (27 ± 4 years, 59.9 ± 6.5 kg, 168.2 ± 6.3 cm, BMI 21.2 ± 1.8) completed unilateral hip extensions on a conical flywheel under both inertia conditions. A rotary encoder measured peak/average power, acceleration, speed, and eccentric-to-concentric (E:C) ratios. Bilateral asymmetries between dominant (DL) and non-dominant (NDL) limbs were assessed. Paired t-tests and Cohen's d were used for analysis.

Results: Higher inertia reduced peak and mean acceleration and speed (p < 0.001, d > 0.8). Eccentric peak power significantly increased in the NDL (p < 0.001, d = 3.952). E:C ratios remained stable.

Conclusions: Greater inertial loads reduce movement velocity but increase eccentric output in the NDL, offering potential strategies to manage neuromuscular asymmetries in elite female football players.

Keywords: acceleration output; cone-shaped prevention exercise; hamstrings asymmetry; inertia load; iso-inertial devices; power output; speed output.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
(a) Initial position for the hip extension exercise using flywheel cone-shape device (90° hip flexion and knee semi-flexion). (b) Final position for the hip extension exercise using flywheel cone-shape device (hip and knee at 0°).
Figure 2
Figure 2
Testing procedures. DL = dominant leg. NDL = non–dominant leg.
Figure 3
Figure 3
NDL concentric and eccentric peak power during the hip extension exercise using a flywheel cone-shape device. # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase.
Figure 4
Figure 4
(a) DL concentric and eccentric peak acceleration during the hip extension exercise using a flywheel cone-shape device. * # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase. (b) NDL concentric and eccentric peak acceleration during the hip extension exercise using a flywheel cone-shape device. * # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase.
Figure 5
Figure 5
(a). DL concentric and eccentric peak speed during the hip extension exercise using a flywheel cone-shape device. * # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase. (b) NDL concentric and eccentric peak speed during the hip extension exercise using a flywheel cone-shape device.
Figure 6
Figure 6
(a) DL concentric and eccentric mean acceleration during the hip extension exercise using a flywheel cone-shape device. * # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase. (b) NDL limb concentric and eccentric mean acceleration during the hip extension exercise using a flywheel cone-shape device.
Figure 7
Figure 7
(a) DL concentric and eccentric mean velocity during the hip extension exercise using a flywheel cone-shape device. * # Statistically significant (p < 0.05) difference between moments of inertia for the concentric phase. (b) NDL concentric and eccentric mean velocity during the hip extension exercise using a flywheel cone-shape device.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Griffin J., Newans T., Horan S., Keogh J., Andreatta M., Minahan C. Acceleration and High-Speed Running Profiles of Women’s International and Domestic Football Matches. Front. Sport Act. Living. 2021;3:604605. doi: 10.3389/fspor.2021.604605. - DOI - PMC - PubMed
    1. Trewin J., Meylan C., Varley M.C., Cronin J., Ling D. Effect of Match Factors on the Running Performance of Elite Female Soccer Players. J. Strength Cond. Res. 2018;32:2002–2009. doi: 10.1519/JSC.0000000000002584. - DOI - PubMed
    1. Bishop C., Turner A., Maloney S., Lake J., Loturco I., Bromley T., Read P. Drop Jump Asymmetry Is Associated with Reduced Sprint and Change-of-Direction Speed Performance in Adult Female Soccer Players. Sports. 2019;7:29. doi: 10.3390/sports7010029. - DOI - PMC - PubMed
    1. Bishop C., Read P., McCubbine J., Turner A. Vertical and Horizontal Asymmetries Are Related to Slower Sprinting and Jump Performance in Elite Youth Female Soccer Players. J. Strength Cond. Res. 2018;1:56–63. doi: 10.1519/JSC.0000000000002544. - DOI - PubMed
    1. Moreno-Azze A., Arjol-Serrano J.L., Falcón-Miguel D., Bishop C., Gonzalo-Skok O. Effects of Three Different Combined Training Interventions on Jump, Change of Direction, Power Performance, and Inter-Limb Asymmetry in Male Youth Soccer Players. Sports. 2021;9:158. doi: 10.3390/sports9120158. - DOI - PMC - PubMed

LinkOut - more resources