The Result of Mid-High-Heeled Footwear on Young Adult Women
dataset . The high drop-out rate at this stage was caused by the poor quality of the fiducial markers . Three subjects had outlier values of SHS and were excluded from the study . Then , five measurements selected as outliers in the vertical balance angle distribution , and four in the pelvic inclination angle distribution were found , nine in total . Distributions of thoracic kyphosis angle and lumbar lordosis angle did not show any outliers . All outliers were examined for any factors that would render them unacceptable for the experiment : faulty posture , measurement and calculation errors . No irregularities were found , and the measurements were kept in the dataset .
After this procedure , 53 complete measurements were left for analysis . The remaining subjects were 20.4 ± 1.2 years old , characterized by BMI 20.2 ± 2.2 . The summary of the calculated angle distributions is presented in Table 1 . Intraclass Correlation Coefficient ( ICC3,3 ) for barefoot measurements are presented in Table 2 . Significant differences between the barefoot and high heel conditions were found in the vertical balance and pelvic inclination angles for p < 0.001 using the Wilcoxon signed-rank test . The thoracic kyphosis and lumbar lordosis angles did not differ significantly . All results of the effect size for the vertical balance angle , the pelvic inclination angle , for thoracic kyphosis angle , and lumbar lordosis angle — small are presented in Table 3 .
The influence of fiducial marker placement was examined for the pelvic inclination and vertical balance angles , where the difference was statistically significant , and the effect size at least small . Ten repetitions of the random movement of the fiducial markers on the measured surface were performed . The displacement of markers was 13.4 ± 7.2 mm . The W statistic for the vertical balance angle was 67 ± 21 with a p-value less than 0.001 for all random runs and 215 ± 18 for the pelvic inclination angle with a p-value less than 0.001 for all random runs . The effect size was −0.90 ± 0.03 in the vertical balance angle ( large effect size in all cases ), and −0.69 ± 0.02 in the pelvic inclination angle ( medium to large effect size in all cases ).
4 . Discussion
There is a lack of consensus in the literature regarding the posture changes caused by the use of high heel shoes due to several factors . This study aimed to investigate how medium-high heeled footwear influences static posture parameters . The majority of the symptoms associated with wearing high-heeled shoes are considered attributable to the observed adaptive biomechanical phenomena .
No significant effects on the lumbar lordosis angle under static conditions found by Schroeder and Hollander [ 4 ] were confirmed in this study . A small reduced pelvic tilt was similarly present . Our study did not confirm any moderately increased transversal pelvic rotation . Other postural effects of high-heeled shoes were mentioned in the literature , namely , head protraction [ 8 ], postural disorders of the head and spine [ 14 ], pelvic anteversion [ 4 , 5 , 9 , 15 , 16 ] , and knee valgus
[ 8,10,16 ]
. Only the selected parameters were evaluated in our study . Head protraction and knee position were not evaluated in the present study . The debate remains open about the potential impact of high heels on posture and lumbar hyperlordosis [ 4 , 9 , 10 , 12 , 15 ] or its decrease [ 6 ] , pelvic tilt changes and wholebody sagittal balance . Silva et al . [ 10 ] reviewed studies searched in the Scopus , SciELO , and PubMed databases between 1980 and 2011
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