AU - Mokhtari Malekabadi, Arefeh AU - Jafarnezhadgero, AmirAli AU - Gghorbanlou, Farshad TI - The Effects of Changing Footstrike Pattern on the Amplitude and Frequency Spectrum of Ground Reaction Forces During Running in Individuals With Pronated Feet PT - JOURNAL ARTICLE TA - USWR JN - USWR VO - 10 VI - 4 IP - 4 4099 - http://ptj.uswr.ac.ir/article-1-423-en.html 4100 - http://ptj.uswr.ac.ir/article-1-423-en.pdf SO - USWR 4 AB  - Purpose: The current study aimed to evaluate the effects of barefoot and shod running with two different styles on ground reaction force-frequency content in recreational runners with low arched feet. Methods: The statistical sample of this research was 13 males with Pronated Feet (PF) (Mean±SD age: 26.2±2.8 y; height: 176.1±8.4 cm; weight: 78.3±14.3 kg). A force plate (Bertec, USA) with a sample rate of 1000 Hz was used to record the reaction forces under each foot. Three test conditions in our study included shod running with rearfoot, midfoot, and forefoot patterns. Repeated-measures Analysis of Variance (ANOVA) was used for analyzing the data. Results: During forefoot running, the research subjects attained 10% higher GRF values in vertical direction, compared with rearfoot running (P˂0.001, d=2.133). Forefoot running decreased the peak vertical GRF, compared to rearfoot running (by 12%, P=0.01, d=0.826). Barefoot running decreased the peak vertical GRF, compared to shod running (by 6%, P=0.027, d=1.143). The collected results revealed a significantly lower FyMed (P<0.02, d=1.11, 14%), Fy99.5% (P<0.02, d=0.11, 8%), and greater FyNe (P<0.02, d=0.72, 10%), Fz99.5% (P<0.01, d=4.30, 124%), and FzNe (P<0.01, d=1.65, 44%) when running with rearfoot strike pattern, compared with forefoot strike pattern. Conclusion: The study subjects with pronated feet experienced greater GRF values during forefoot running than rearfoot; such data may imply an increased risk of running injuries. Therefore, forefoot running is not recommended for runners with pronated feet. CP - IRAN IN - Department of Physical Education and Sport Sciences, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, Ardebil, Iran LG - eng PB - USWR PG - 205 PT - Research YR - 2020