Comparing Frequency Spectrum of Ground Reaction Forces in Blind and Healthy Participants With Open and Closed Eyes During Walking

Abstract

Background and Aims This study aimed to compare the frequency spectrum of ground reaction forces in blind and healthy participants with open and closed eyes during walking. Methods This study was quasi-experimental. The statistic samples comprised 15 blind men with a mean age of 25.22±6.33 years and 15 healthy men with a mean age of 27.22±5.31 years. They were selected by available sampling. A foot scan (RS Scan International, Belgium) device was used to measure the foot pressure values while walking. Variables of foot pressure were recorded at a sampling frequency of 300 Hz. For data analysis, we used the paired t test to compare the within-group means and the independent t test to compare the between-group means in SPSS software, version 24. Results The results showed that the frequency content with 99.5% power was greater in the blind group than in the healthy group with open eyes in the vertical direction, first metatarsal, and lateral and medial heel parts (P<0.05). Also, the frequency content with 99.5% power was greater in the healthy group with closed eyes than those healthy ones with open eyes (P<0.05). The frequency content with 99.5% power (P=0.004) and numbers of essential harmonics (P=0.003) in the vertical direction in the blind group were respectively 9.84% and 13.51% less than the healthy group with closed eyes. The number of essential harmonics (P=0.002) in the vertical direction in the healthy group with closed eyes was 20.61% greater than those healthy ones with open eyes. The frequency content with 99.5% power in the vertical direction in the blind group was less than that of the healthy group with closed eyes (P=0.023). Conclusion Considering the increase in frequency with 99.5% power and the number of essential harmonics in different areas of the soles of the foot in the blind group and healthy group with closed eye, it is recommended that physiotherapists, motion analysts, and rehabilitation specialists design a special rehabilitation protocol for blind people and those who lost their vision due to an accident.