Effect of double- density foot orthoses on ground reaction forces and lower limb muscle activities during running in adults with and without pronated feet

Ebrahim Piri; Vahid Sobhani; AmirAli Jafarnezhadgero; Ehsan Arabzadeh; Alireza Shamsoddini; Matteo Zago; Urs Granacher

doi:10.1186/s13102-025-01095-5

Effect of double- density foot orthoses on ground reaction forces and lower limb muscle activities during running in adults with and without pronated feet

BMC Sports Sci Med Rehabil. 2025 Mar 21;17(1):54. doi: 10.1186/s13102-025-01095-5.

Authors

Ebrahim Piri¹, Vahid Sobhani², AmirAli Jafarnezhadgero³, Ehsan Arabzadeh⁴, Alireza Shamsoddini⁴, Matteo Zago⁵, Urs Granacher⁶

Affiliations

¹ Student Research Committee, Baqiyatallah University of Medical Sciences, Tehran, Iran.
² Exercise Physiology Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran. sobhani518@gmail.com.
³ Department of Sports Biomechanics, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran.
⁴ Exercise Physiology Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
⁵ Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy.
⁶ Department of Sport and Sport Science, Exercise and Human Movement Science, University of Freiburg, Freiburg, Germany. urs.granacher@sport.uni-freiburg.de.

Abstract

Background: The analysis of ground reaction forces and muscle activities during walking or running can help clinicians decide on the usage of foot orthoses, particularly in individuals with pronated feet. Here, we aimed to investigate the effects of double- density foot orthoses on running kinetics and lower limb muscle activities in adults with and without pronated feet.

Methods: Forty male adults with pronated feet (PF: n = 20, age = 25.4 ± 0.3 years, body-mass-index [BMI] = 23.3 ± 1.2 kg/m²) and without pronated feet (WPF: n = 20, age = 26.4 ± 1.0 years, BMI = 24.0 ± 0.7 kg/m²) volunteered to participate in this study. The study was registered with the Iranian Registry of Clinical Trials (IRCT20220129053865N1). Ground reaction forces (F_x, F_y, F_z) and lower limb muscle activities (e.g., m. gastrocnemius) were recorded using surface electromyography (EMGs) during running at a constant speed of 3.2 m/s over an 18-m walkway with an embedded force plate. EMGs were normalized to maximum voluntary isometric contractions.

Results: Test-retest reliability for running speed data was excellent for PF and WPF groups and for the entire study cohort with intraclass correlation coefficients > 0.95. The 2-way ANOVA revealed lower peak F_z (p = 0.011; d = 1.226), lower time-to-peak for F_x (p = 0.023, d = 1.068), F_y (p = 0.025, d = 1.056), and F_z (p = 0.045, d = 0.931) during running with foot orthoses in PF individuals. During the loading phase, PF and WPF exhibited lower gastrocnemius (WPF: p = 0.005, d = 1.608; PF: p = 0.001, d = 2.430 ) and vastus medialis (WPF: p < 0.001, d = 2.532; PF: p < 0.001, d = 2.503) activity when running with foot orthoses.

Conclusions: Although double- density foot orthoses resulted in some beneficial biomechanical effects such as lower muscle activation (e.g., m. vastus medialis) in individuals with PF, foot orthoses constructions need further modifications to achieve even better running mechanics to enhance performance and lower limbinjury occurrence.

Trial registration: IRCT20220129053865N1 (Registration date 19/08/2024).

Keywords: Electromyography; Flat feet; Gait analysis; Insoles; Kinetics.