ArticleOpen Access http://dx.doi.org/10.26855/hpj.2025.12.005
The Effect of Custom Orthotic Insoles on Lower Limb Muscle Fatigue in Patients with Flat Feet
Xiaoran Wang
Beijing 101 Middle School, Beijing 100000, China.
*Corresponding author: Xiaoran Wang
Published: November 14,2025
Abstract
Flat feet, a common foot structural abnormality, seriously affects an individual’s health and quality of life. This study aims to evaluate the impact of custom orthotic insoles on sports biomechanical characteristics such as muscle fatigue in patients with flat feet. A self-controlled crossover design was adopted, with a 25-year-old male patient with flexible flat feet as the subject. In two experiments separated by one week, the subject wore ordinary insoles (control group) and custom orthotic insoles (experimental group) respectively, and ran continuously on a treadmill at 8 km/h for 30 minutes. Surface electromyographic (sEMG) signals of the gastrocnemius muscle (sampling rate: 2000 Hz) and plantar pressure data were collected simultaneously. Indicators including integrated electromyog-raphy (iEMG), maximum iEMG, mean frequency (MF), and plantar peak pressure were compared. In the early stage of exercise (1–6 minutes), the iEMG of the experimental group was significantly higher than that of the control group [(16,096.78 ± 1,235.73) vs (9,908.63 ± 531.04)], with an increase of 62.45% (p < 0.001); the maximum iEMG increased by approximately 101% [(675.68 ± 129.35) vs (335.77 ± 34.58), p < 0.001]. In the late stage of exercise (7–30 minutes), the iEMG of the control group surged to (27,434.87 ± 11,424.37), while that of the experimental group remained at (16,409.57 ± 1,436.47), with a near-significant difference (p = 0.052). The decrease amplitude of MF in the con-trol group was approximately 40% higher than that in the experimental group, and the increase in fatigue slope was more than 112 times. The average plantar peak pressure in the experimental group decreased by about 12%, and the center of gravity trajectory was closer to the midline. These results indicate that custom orthotic insoles can effectively optimize plantar pressure distribution, delay the occurrence of muscle fatigue, and may improve neuromuscular control efficiency. This study confirms the positive role of custom orthotic insoles in improving exercise performance and reducing the risk of sports injuries in patients with flat feet.
Keywords
Flat feet; Custom insoles; Plantar pressure; Surface electromyography (sEMG); Muscle fatigue
References
[1] Bai X, Huo H, Zhao H, et al. Effect of orthotic insoles on lower limb motor function during the stance phase of walking in patients with flat feet. Chin J Sports Med. 2022;41(5):361-8.
[2] Cao P, Wang B, Cong Y, et al. Evaluation study on the correction effect of orthotic insoles on flat feet. J Imaging Res Med Appl. 2017;1(18):184-6.
[3] Huang Y, Wang Y, Wang J, Sun W. The arch support insoles show benefits to people with flatfoot on stance time, cadence, plantar pressure and contact area. PLoS One. 2020;15(8):e0237382.
[4] Kirmizi M, Elvan A, Akcali DT, Caglar NS. Effects of foot exercises and customized arch support insoles on foot posture, plantar force distribution, and balance in people with flexible flatfoot: a randomized controlled trial. Gait Posture. 2024;113:106-14.
[5] Wang Y, Wang J, Sun W. Effect of orthotic insoles on plantar pressure distribution of flat-footed college students before and after running fatigue. J Med Biomech. 2024;39(S1):464.
[6] Wang Y, Zhou Z, Sun W, et al. Effect of orthotic insoles on plantar pressure during running in flexible flat-footed individuals under fatigue state. Leather Sci Eng. 2025;35(2):66-72.
[7] Xu Q, Guo Y, Zhang X, et al. Biomechanical analysis of the effect of orthotic insoles on the lower limbs of patients with flat feet. J Taiyuan Univ Technol. 2024;55(2):390-8.
[8] Aghaie Ataabadi P, Abbasi A, Letafatkar A. Short-Term Effects of Foot Orthoses and Antipronation Taping on the Center of Pressure and Ground Reaction Forces of People With Flat Feet During Running. Sci J Rehabil Med. 2024;13(2):274-89.
How to cite this paper
The Effect of Custom Orthotic Insoles on Lower Limb Muscle Fatigue in Patients with Flat Feet
How to cite this paper: Xiaoran Wang. (2025) The Effect of Custom Orthotic Insoles on Lower Limb Muscle Fatigue in Patients with Flat Feet. Health and Prevention Journal, 2(1), 54-60.
DOI: http://dx.doi.org/10.26855/hpj.2025.12.005