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INTRODUCTION: The aim of the present study was to investigate the effect of Internal and External Heel Lift Insoles (IHLI, EHLI) on pelvic kinematics and lower extremity joint moments in subject with mild leg length discrepancy (LLD) during the Stance Phase of walking. METHODS: From twenty-eight men with mild LLD, kinematic and kinetic data were collected while they walked under each of three conditions (IHLI, EHLI and shoe). Data were collected for both limbs using a six-camera system synchronized with a force platform. For comparisons the dependent variables among the conditions, repeated measures ANCOVA and Bonferroni's post hoc test were used (P ≤ 0.05). RESULTS: For both IHLI and EHLI, there were significant decreases in peak long leg lateral and anterior pelvic tilt, long leg hip and knee abduction moments, and short leg ankle plantar flexor moment (P ≤ 0.001). Furthermore, significant increases in peak lateral and anterior pelvic tilt of the short leg were observed in the IHLI and EHLI conditions as compared to the shoe (SH) condition (p ≤ 0.01). In addition, a significant difference was observed between the IHLI and EHLI conditions in the peak values of anterior pelvic tilt of the long leg (p = 0.043) and ankle plantar flexor moment of the short leg (p = 0.044). CONCLUSION: Findings suggest that the use of IHLI and EHLI may be effective in improving pelvic movements (lateral and anterior tilt) and gait dynamics in individuals with LLD. The EHLI could reduce more the peak plantar flexor moment of the short leg and peak anterior pelvic tilt of the long leg than IHLI during stance phase of walking.

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BACKGROUND: The development of the norm of functional variables of fitness as a national database was considered the most important criterion of success in basketball. The current study aims to investigate the performance and skill-related determinants of physical fitness. METHODS: Forty-three elite basketball players (including 14 centers, 15 forward and 14 guard players) participated in this cross-sectional study. The biomechanical parameters of the vertical jump and on-court tests including 20-meter dash, 4×9m agility, 10×20 m shuttle run, repeated side hop, were evaluated. The values of these parameters were compared between different posts using MANOVA and Tukey Post hoc tests in SPSS software (P≤0.05). RESULTS: The norm of physical fitness parameters was obtained by determining the percentage points of 0-10%, 10-25%, 25-50%, 50-75%, 75-90% and 90-100%. Furthermore, peak vertical jump velocity and relative jump power were significantly higher in the guards and forwards compared to the centers (P=0.007 and P=0.027, respectively). The forwards showed significantly higher mean agility, repeated shuttle running, and EUR compared to the centers (P<0.001, P=0.020 and P=0.04, respectively). The repeated side jump was significantly lower in the centers by 8% compared to the guards (P=0.01). CONCLUSIONS: It was concluded that exercises for guards with a stronger emphasis on agility and explosiveness (plyometric exercises) in combination with aerobic fitness should be considered. Center players can benefit from resistance training in combination with jumping skills. Speed endurance and anaerobic power in skill related maneuvers are parameters of the players' poor performance in all three positions.

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Running on side-sloped surfaces is a common obstacle in the environment; however, how and to what extent the lower extremity kinematics adapt is not well known. The purpose of this study was to determine the effects of side-sloped surfaces on three-dimensional kinematics of hip, knee, and ankle during stance phase of running. Ten healthy adult males ran barefoot along an inclinable runway in level (0°) and side-sloped (10° up-slope and down-slope inclinations, respectively) configurations. Right hip, knee, and ankle angles along with their time of occurrence were analysed using repeated measures MANOVA. Up-slope hip was more adducted (p = 0.015) and internally rotated (p = 0.030). Knee had greater external rotations during side-sloped running at heel-strike (p = 0.005), while at toe-off, it rotated externally and internally during up-slope and down-slope running, respectively (p = 0.001). Down-slope ankle had greatest plantar flexion (p = 0.001). Up-slope ankle had greatest eversion compared with down-slope (p = 0.043), while it was more externally rotated (p = 0.030). These motion patterns are necessary to adjust the lower extremity length during side-sloped running. Timing differences in the kinematic events of hip adduction and external rotation, and ankle eversion were observed (p = 0.006). Knowledge on these alterations is a valuable tool in adopting strategies to enhance performance while preventing injury.

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Foot pronation has not been quantified dynamically in three planes of movement in an in-vivo study. The aims of this study were to determine foot pronation through using Principal Component Analysis (PCA) method and to compare it among barefoot, shod and shod with 6° lateral wedge during the stance phase of running. In this method, three-dimension of foot movements were measured and each of these components represents a percentage of foot pronation. These components were derived based on eigenvalues and vectors of covariance matrix of primary variables. The first (PC1), second (PC2) and third (PC3) components explained about (82.5%, 79.1%), (14%, 15.8%) and (3.5%, 5.1%) the foot pronation for barefoot and shod conditions, respectively. These components were mutually independent and the components set had the same information as the primary variables. Foot pronation index and eversion angles were calculated and compared among barefoot, shod and shod with wedge insole (6° lateral wedge insole) conditions in the four phases of stance. Statistical analysis showed that there was no foot conditions effect for foot eversion in four phases (p=0.72), while this effect was significant for PC1 (p=0.001). This finding shows that PC1 index could discriminate footwear effect among each phase of stance. Specifically, pronation was reduced in shoe condition as compared to barefoot condition (p=0.02) from 5 to 50% of stance phase. It has been suggested that the PCA method provides more accurate criteria for investigating effects of footwear interventions on simultaneous three-dimensional foot motion.

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An alternative scheme for improvement of computational ghost imaging (GI) features is proposed based on a three-color fluorescent screen. While a monochrome fluorescent screen does not enhance the quality of ghost images in comparison with the ordinary GI technique, employment of a multi-fluorescent screen can be very effective. It is shown that the visibility, signal to noise ratio (SNR), and contrast to noise ratio (CNR) of the resultant ghost images are improved when a multi-fluorescent screen is used. In particular, the results prove 65%, 36%, and 95% improvement for visibility, SNR, and CNR over 2000 shots, respectively. Also shown is the possibility of reconstructing ghost images over a reduced number of shots (as small as 25) by increasing the number of colors on the screen, whereas ordinary GI is not possible with such a small number of shots. The results from simulations are checked with conducted experiments, and a good agreement between them is observed.

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There is evidence to suggest that navicular drop measures are associated with specific lower-extremity gait biomechanical parameters. The aim of this study was to examine the relationship between navicular drop and a) rearfoot eversion excursion, b) tibial internal rotation excursion, c) peak ankle inversion moment, and d) peak knee adduction moment during the stance phase of running. Sixteen able-bodied men having an average age of 28.1 (SD=5.30) years, weight of 81.5 (SD=10.40) kg, height of 179.1 (SD=5.42) cm volunteered and ran barefoot at 170 steps/minute over a force plate. Navicular drop measures were negatively correlated with tibial internal rotation excursion (r=-0.53, P=.01) but not with rearfoot eversion excursion (r=-0.19; P=.23). Significant positive correlations were found between navicular drop and peak knee adduction moment (r=.62, P<.01) and peak ankle inversion moment (r=.60, P<.01). These findings suggest that a low navicular drop measure could be associated with increasing tibial rotation excursion while high navicular drop measure could be associated with increased peak ankle and knee joint moments. These findings indicate that measures of navicular drop explained between 28% and 38% of the variability for measures of tibial internal rotation excursion, peak knee adduction moment and peak ankle inversion moments.

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OBJECTIVES: The purpose of this study was to examine the influence of semi-rigid foot orthoses on forefoot-rearfoot joint coupling patterns in individuals with different navicular drop measures during heel-toe running. DESIGN: Ten trials were collected from twenty-three male subjects who ran slowly shod at 170 steps per minute (2.23m/s) with a semi-rigid orthoses and without. METHODS: Forefoot-rearfoot coupling motions were assessed using a vector coding technique during four intervals across the first 50% of stance. Subjects were divided into two groups based on navicular drop measures. A three way ANOVA was performed to examine the interaction and main effects of stance interval, orthoses condition and navicular drop (p<0.05). RESULTS: There were no interaction effects among stance interval, orthoses condition, or navicular drop (p=0.14) whereas an interaction effect of orthoses condition and stance interval was observed (p=0.01; effect size=0.74). Forefoot-rearfoot coupling motion in the no-orthoses condition increased from heel-strike to foot-flat phase at a rate faster than the orthoses condition (p=0.02). CONCLUSIONS: Foot orthoses significantly decrease the forefoot-rearfoot joint coupling angle by reducing forefoot frontal plane motion relative to the rearfoot. Navicular drop measures did not influence joint coupling relationships between the forefoot and rearfoot during the first 50% of stance regardless of orthotic condition.

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BACKGROUND: Changes in foot orientation due to orthoses and the relationship with perceived comfort are still unclear in pes cavus. The purpose of this study was to determine the acute changes of fore-foot angles due to the use of custom-made orthoses and their relationship with perceived comfort during standing. METHODS: Two photographs were taken using a color-coded camera-based system from the posterior and medial views of 20 subjects with bilateral pes cavus under barefoot and with orthoses conditions during standing. Djian-Annonier, calcaneal inclination, 1st metatarsal declination and rearfoot angles were measured and perceived comfort in the forefoot, midfoot and rearfoot was estimated using an adapted Visual Analogue Scale-type questionnaire. RESULTS: In comparison with the barefoot condition, orthoses increased significantly the 1st metatarsal declination angle by 1.9 degrees (p<0.01), and the Djian-Annonier angle by 1.1 degrees (p=0.02). The calcaneal inclination angle decreased significantly by an average of 3.0 degrees (p<0.01). Wearing orthoses significantly improved perceived comfort in forefoot, midfoot and rearfoot when compared to barefoot condition (p<0.01). A significant correlation was observed between variation of calcaneal inclination angle and the perceived comfort at the midfoot (r=-0.44; p=0.04). CONCLUSION: Flattening of foot arch and improvement of midfoot perceived comfort in pes cavus could be attributed to the reduction of the calcaneal inclination angle in the sagittal plane by using orthoses during standing.

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Changes in magnitude and timing of rearfoot eversion and tibial internal rotation by foot orthoses and their contributions to vertical ground reaction force and knee joint moments are not well understood. The objectives of this study were to test if orthoses modify the magnitude and time to peak rearfoot eversion, tibial internal rotation, active ground reaction force and knee adduction moment and determine if rearfoot eversion, tibial internal rotation magnitudes are correlated to peak active ground reaction force and knee adduction moment during the first 60% stance phase of running. Eleven healthy men ran at 170 steps per minute in shod and with foot orthoses conditions. Video and force-plate data were collected simultaneously to calculate foot joint angular displacement, ground reaction forces and knee adduction moments. Results showed that wearing semi-rigid foot orthoses significantly reduced rearfoot eversion 40% (4.1 degrees ; p=0.001) and peak active ground reaction force 6% (0.96N/kg; p=0.008). No significant time differences occurred among the peak rearfoot eversion, tibial internal rotation and peak active ground reaction force in both conditions. A positive and significant correlation was observed between peak knee adduction moment and the magnitude of rearfoot eversion during shod (r=0.59; p=0.04) and shod/orthoses running (r=0.65; p=0.02). In conclusion, foot orthoses could reduce rearfoot eversion so that this can be associated with a reduction of knee adduction moment during the first 60% stance phase of running. Finding implies that modifying rearfoot and tibial motions during running could not be related to a reduction of the ground reaction force.

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BACKGROUND: Based on twisted plate and mitered hinge models of the foot and ankle, forefoot-rearfoot coupling motion patterns can contribute to the amount of tibial rotation. The present study determined the differences of forefoot-rearfoot coupling patterns as well as excessive excursion of tibial internal rotation in shod versus barefoot conditions during running. METHODS: Sixteen male subjects ran 10 times at 170 steps per minute under the barefoot and shod conditions. Forefoot-rearfoot coupling motions were assessed by measuring mean relative phase angle during five intervals of stance phase for the main effect of five time intervals and two conditions (ANOVA, P<0.05). Tibial internal rotation excursion was compared between the shod and barefoot conditions over the first 50% of stance phase using paired t-test, (P<0.05). FINDINGS: Forefoot adduction/abduction and rearfoot eversion/inversion coupling motion patterns were significantly different between the conditions and among the intervals (P<0.05; effect size=0.47). The mean absolute relative angle was significantly modified to 37 degrees in-phase relationship at the heel-strike of running with shoe wears. No significant differences were noted in the tibial internal rotation excursion between shod and barefoot conditions. INTERPRETATION: Significant variations in the forefoot adduction/abduction and rearfoot eversion/inversion coupling patterns could have little effect on the amount of tibial internal rotation excursion. Yet it remains to be determined whether changes in the frontal plane forefoot-rearfoot coupling patterns influence the tibia kinematics for different shoe wears or foot orthotic interventions. The findings question the rational for the prophylactic use of forefoot posting in foot orthoses.

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