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A comparison of ground reaction force frequency content between rearfoot and non-rearfoot contact patterns during sidestep cutting
Oral Presentation
Paper ID : 1853-11THCONF
Authors
1کارشناس ارشد/دانشگاه مازندران
2آکادمی ملی المپیک
Abstract
Introduction: It has been reported that a large number of lower extremity injuries occurs during collision of the rear-foot with the ground during sidestep cutting. Recently scarce studies have shown that frequency contents of contact forces in different directions could justify injury mechanisms. Hence, the purpose of this study was to compare the frequency contents of contact forces between two types of contact patterns during sidestep cutting.
Methodology: Thirteen national squash players ran a 5 meter walk way before arriving to force plate. Consequently they had 5 ± 45 degrees direction change after collision to force plate in unanticipated sidestep cutting by dominant leg and data was recorded by Bioware software. The contact patterns were recorded as rear-foot and non rear-foot. The frequency of vertical and anterior-posterior ground reaction force (GRF) components was determined using Fast Fourier Transform (FFT). One way ANOVA was applied to test the hypothesis using SPSS software (p<0.05).
Results: Results showed significantly more values in 99.5% power spectrum of anterior-posterior GRFs in non rear-foot contact than rear-foot contact (p=0.04) but there was no significant difference in vertical direction (p=0.5). In addition frequency domain of vertical GRFs in rear-foot contact was significantly more than non rear-foot contact (p=0.04), but no significant differences were found in anterior-posterior frequency domain (p=0.5).
Discussion: Based on previous research findings more power spectrum frequency in rear foot contact may place more stress on musculoskeletal structures of the knee in comparison with ankle which might result in possible knee injuries. In conclusion, frequency content analysis might explain differences between sidestep cutting contact patterns regarding to injury mechanisms. However the results of this study should be considered by cautions because of small sample sizes.
Methodology: Thirteen national squash players ran a 5 meter walk way before arriving to force plate. Consequently they had 5 ± 45 degrees direction change after collision to force plate in unanticipated sidestep cutting by dominant leg and data was recorded by Bioware software. The contact patterns were recorded as rear-foot and non rear-foot. The frequency of vertical and anterior-posterior ground reaction force (GRF) components was determined using Fast Fourier Transform (FFT). One way ANOVA was applied to test the hypothesis using SPSS software (p<0.05).
Results: Results showed significantly more values in 99.5% power spectrum of anterior-posterior GRFs in non rear-foot contact than rear-foot contact (p=0.04) but there was no significant difference in vertical direction (p=0.5). In addition frequency domain of vertical GRFs in rear-foot contact was significantly more than non rear-foot contact (p=0.04), but no significant differences were found in anterior-posterior frequency domain (p=0.5).
Discussion: Based on previous research findings more power spectrum frequency in rear foot contact may place more stress on musculoskeletal structures of the knee in comparison with ankle which might result in possible knee injuries. In conclusion, frequency content analysis might explain differences between sidestep cutting contact patterns regarding to injury mechanisms. However the results of this study should be considered by cautions because of small sample sizes.
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