How well does virtual reality replicate real-world side-step cutting in football? A Study Protocol

Abstract

Anterior cruciate ligament (ACL) ruptures are among the most severe injuries in football, with

female athletes facing a disproportionately high risk due to anatomical, hormonal, and

biomechanical differences (Mancino et al., 2024). A significant proportion of these injuries

occur during non-contact defensive scenarios, particularly side-step cutting movements

(Kaneko et al., 2016). While injury prevention programs exist, their effectiveness remains

limited (Weitz et al., 2020), highlighting the need for more targeted and innovative approaches.

Virtual reality (VR) has emerged as a promising tool in sports training and rehabilitation,

offering immersive, controlled environments for movement practice (Li et al., 2025). However,

before VR-based interventions can be confidently implemented, it is essential to establish

whether movement patterns performed within a virtual environment are comparable to those

in real-world conditions.

This study investigates whether lower-limb kinematics during a football-specific side-step

cutting task differ between a virtual reality environment and a real-world setting in female

football players. A VR scenario was developed in the Unity game engine to simulate a scenario

in which a virtual character approaches the athlete and he has to perform a side-step cut to

block them.

70 female athletes without prior ACL injury history from various recreational football levels will

perform 15 trials of this scenario in both the real-world and VR setting. Sample size was

determined by an a prior power analysis for a repeated-measures comparison (α = .05, power

= .80, medium effect size d = 0.4–0.5), yielding a minimum of ~60 completers, inflated to 70 to

account for an anticipated 15% dropout rate, while also generating approximately 1,000

biomechanical data samples sufficient for machine learning analyses in future studies. During

the tasks in the VR athletes wear a head-mounted display and consumer grade VR trackers

to capture the motion of the lower limbs and to display the athlete’s motions in the VR

environment. Additionally, motion capture data will be recorded simultaneously using multiple

cameras and analyzed with the post-processing software Theia3D, serving as the gold-

standard reference for kinematic variables known to be associated with ACL injury risk,

including knee and hip joint angles. Following the VR session participants will complete the

Igroup Presence Questionnaire to evaluate their subjective experience of immersion, usability,

and fatigue.

The primary aim of this study is to determine the ecological validity of the VR scenario by

identifying potential differences in biomechanical movement patterns between real-world and

VR conditions like approach velocity, ground contact time, movement onset / reaction time and

the step width at initial contact. Proofing the equivalence is a critical prerequisite for the

subsequent studies in further projects, which will use VR as a platform for individualized motor

learning interventions targeting ACL injury prevention. If movement patterns in VR closely

mirror those observed in real-world settings, this would provide a strong foundation for using

immersive virtual environments as a safe, scalable, and ecologically valid training and

assessment tool for female football players at risk of ACL injury.

References

Kaneko, S., Sasaki, S., Hirose, N., Nagano, Y., Fukano, M., & Fukubayashi, T. (2016).

Mechanism of Anterior Cruciate Ligament Injury in Female Soccer Players (Research

Article No. 8; Issue 1, p. e13322). Asian Journal of Sports Medicine.

https://doi.org/10.5812/asjsm.38205

Li, Y., Peng, J., Cao, J., Ou, Y., Wu, J., Ma, W., Qian, F., & Li, X. (2025). Effectiveness of

virtual reality technology in rehabilitation after anterior cruciate ligament

reconstruction: A systematic review and meta-analysis. PLOS ONE, 20(3), e0314766.

https://doi.org/10.1371/journal.pone.0314766

Mancino, F., Kayani, B., Gabr, A., Fontalis, A., Plastow, R., & Haddad, F. S. (2024). Anterior

cruciate ligament injuries in female athletes: Risk factors and strategies for

prevention. Bone & Joint Open, 5(2), 94–100. https://doi.org/10.1302/2633-

1462.52.BJO-2023-0166

Weitz, F. K., Sillanpää, P. J., & Mattila, V. M. (2020). The incidence of paediatric ACL injury

is increasing in Finland. Knee Surgery, Sports Traumatology, Arthroscopy, 28(2),

363–368. https://doi.org/10.1007/s00167-019-05553-9