Anterior Posterior Foot Research Articles

The Influence of Medial and Lateral Forefoot Height Discrepancy on Lower Limb Biomechanical Characteristics during the Stance Phase of Running

Previous research has predominantly focused on the biomechanical effects of anterior–posterior foot motion during running, with comparatively less attention given to medial–lateral foot motion and its impact on lower limb biomechanical characteristics. We recruited 18 healthy runners who wore five different types of running shoes: regular shoes (NS), those with a 6 mm and 9 mm medial–lateral height difference in the forefoot (M6, M9), and those with a 6 mm and 9 mm lateral–medial height difference (L6, L9). Biomechanical parameters of lower limb joints during the stance phase of running, including range of motion, peak angular velocity, peak moment, power, and work, were analyzed. We used paired-sample t-tests and one-dimensional statistical parametric mapping (SPM1D) to compare joint biomechanics between shoes with varying height differences and NS. Under the L6 condition, notable differences occurred in the hip and knee flexion–extension moments during landing and push-off, accompanied by a significant increase in ankle dorsiflexion work and a significant decrease in inversion–eversion work. In contrast, the M9 condition resulted in decreased hip flexion–extension peak moment, power, and work in the sagittal plane. These findings indicate that varying forefoot medial–lateral height differences in running shoes significantly impact lower limb joint dynamics during the stance phase, particularly the L6 condition, potentially reducing knee injury risk and aiding gait improvement for overpronators. The findings offer valuable insights for sports injury prevention and athletic footwear design. However, further research is needed to understand the underlying mechanisms and practical implications for sports injury prevention and performance enhancement.

THE IMPACT OF PLANTAR OSCILLATION ON SHOOTING ACCURACY: A PRE- AND POST-TEST ANALYSIS OF CENTER OF PRESSURE IN COMPETITIVE SHOOTERS

This study aimed to evaluate the impact of a targeted intervention on plantar oscillation in professional shooters, focusing on both medial-lateral and anterior-posterior foot movements. Thirty professional shooters participated in pre-and post-test assessments of foot oscillation using stabilometric measurements. Paired sample t-tests were conducted to compare oscillations in the left foot, right foot, and both feet combined before and after the intervention. Significant improvements were observed in medial-lateral oscillation for the right foot (p = 0.017) and both feet combined (p = 0.013), indicating enhanced lateral stability post-intervention. However, no significant changes were found in anterior-posterior movements for either foot (p > 0.05). These findings suggest that the intervention successfully improved lateral balance but had a limited impact on forward-backward stability. Future interventions should incorporate additional activities to target anterior-posterior control for improved overall postural stability in shooting performance.

Evaluation of the Entrance Surface Doses (ESD) for common diagnostic X-ray examinations

ObjectiveThe purpose of this study was to assess the Entrance Skin Dose (ESD) in patients undergoing multiple types of radiographic examinations across three hospitals in Saudi Arabia. MethodsThe patient ESD was estimated directly using optically stimulated luminesces (OSL) and indirectly using a survey meter and calculations for 100 adult patients undergoing common diagnostic X-ray examinations, including a posterior anterior chest, posterior anterior hand, anterior posterior foot, and anterior posterior knee examinations, in three hospitals in Saudi Arabia. Comparative analysis with national and international reference values was conducted. ResultsOur analyses revealed considerable heterogeneity in X-ray exposure parameters among the hospitals. The mean ESD values for the chest examination were 0.28 ± 0.13 mGy for the direct method and 0.19 ± 0.11 mGy for the indirect method. Hand examination using the direct method resulted in a mean ESD of 0.42 ± 0.15 mGy, while the indirect method yielded 0.23 ± 0.06 mGy. Remarkably, the ESD values in most cases exceeded national and international guidelines, with the knee examination ESD using the direct and indirect methods showing an alarming value of 1.54 ± 0.31 mGy and 1.18 ± 0.21 mGy, respectively. The correlation between direct ESD, indirect ESD showed a strong positive correlation exists between direct ESD and Indirect ESD (r = 0.8, p < 0.001). ConclusionThe study highlights the urgent need for standardized protocols and quality control measures across radiographic facilities in Saudi Arabia. The elevated ESD values signify a critical issue that requires immediate attention to minimize patient radiation exposure while maintaining diagnostic image quality. Quality control tests and adjustments in examination parameters are strongly advised.

Does ankle push-off correct for errors in anterior-posterior foot placement relative to center-of-mass states?

Understanding the mechanisms humans use to stabilize walking is vital for predicting falls in elderly. Modeling studies identified two potential mechanisms to stabilize gait in the anterior-posterior direction: foot placement control and ankle push-off control: foot placement depends on position and velocity of the center-of-mass (CoM) and push-off covaries with deviations between actual and predicted CoM trajectories. While both control mechanisms have been reported in humans, it is unknown whether especially the latter one is employed in unperturbed steady-state walking. Based on the finding of Wang and Srinivasan that foot placement deviates in the same direction as the CoM states in the preceding swing phase, and assuming that this covariance serves the role of stabilizing gait, the covariance between the CoM states and foot placement can be seen as a measure of foot placement accuracy. We subsequently interpreted the residual variance in foot placement from a linear regression model as "errors" that must be compensated, and investigated whether these foot placement errors were correlated to push-off kinetic time series of the subsequent double stance phase. We found ankle push-off torque to be correlated to the foot placement errors in 30 participants when walking at normal and slow speeds, with peak correlations over the double stance phase up to 0.39. Our study suggests that humans use a push-off strategy for correcting foot placement errors in steady-state walking.

少林寺拳法の経験が足趾把持力，接地足蹠形態，および前後足圧荷重割合に及ぼす影響

少林寺拳法の経験が足趾把持力，接地足蹠形態，および前後足圧荷重割合に及ぼす影響

Relation between Anterior-Posterior Foot Pressure Ratio and Kindergartens’ Barefoot Policy

This study aimed at clarifying the relation between anterior-posterior foot pressure ratio and kindergartens’ barefoot policy. Participants included 257 preschool children (125 boys and 132 girls) attending kindergartens with a barefoot policy and 316 preschool children (157 boys and 159 girls) attending kindergartens without this policy. An instrument called Foot view Clinic was used to measure the anterior- posterior foot pressure ratio. Participants maintained an upright posture on the instrument for 10 seconds. The posterior foot pressure proportion for each participant’s feet was used to evaluate heel load, and the mean of a 10-second measurement was used for analysis. Among boys, posterior foot pressure was significantly lower for those attending kindergartens following a barefoot policy than for those attending kindergartens not following a barefoot policy. On the other hand, no significant difference was observed in the posterior foot pressure ratio between girls who played barefoot and those who did not. Therefore, in conclusion, kindergartens’ barefoot policy affects children’s anterior-posterior foot pressure ratio and reduces the posterior foot pressure ratio in boys.

Age-related, interindividual, and right/left differences in anterior-posterior foot pressure ratio in preschool children

BackgroundThis study aimed to examine age-related, interindividual, and right/left differences in anterior-posterior foot pressure ratio in 764 preschool children (364 boys and 400 girls) aged 3.5-6.5 years.MethodsSubjects maintained an upright standing posture for 10 seconds on the Footview Clinic, an instrument designed to calculate the anterior-posterior foot pressure ratio. The ratio of anterior foot pressure in each subject’s right and left feet was selected as a variable, and the mean of a 10 s measurement was used for analysis.ResultsThe ratio of anterior foot pressure was significantly larger in the right foot than in the left foot. With regard to age, the ratio of anterior foot pressure was significantly larger in children aged over 4.5 years than in children aged 3.5 years. It was also larger in children aged 6 and 6.5 years than in children aged 4 years. Interindividual differences in variables were large, and coefficients of variance were highest in children aged 3.5 years and lowest in children aged 6.5 years.ConclusionsIn conclusion, anterior foot pressure increases with age in preschool children. Interindividual differences in anterior foot pressure are large and tend to decrease with age. Furthermore, the anterior foot pressure is slightly higher in the right foot than in the left foot. These results will be useful for various studies, such as examining relationships between the anterior-posterior foot pressure ratio and factors, such as untouched toes, physical fitness, and level of exercise.

Is economy of competitive cyclists affected by the anterior–posterior foot position on the pedal?

The primary purpose of this investigation was to test the hypothesis that cycling economy, as measured by rate of oxygen consumption ( V ˙ O 2 ) in healthy, young, competitive cyclists pedaling at a constant workrate, increases (i.e. V ˙ O 2 decreases) when the attachment point of the foot to the pedal is moved posteriorly on the foot. The V ˙ O 2 of 11 competitive cyclists (age 26.8±8.9 years) was evaluated on three separate days with three anterior–posterior attachment points of the foot to the pedal (forward=traditional; rear=cleat halfway between the head of the first metatarsal and the posterior end of the calcaneous; and mid=halfway between the rear and forward positions) on each day. With a randomly selected foot position, V ˙ O 2 was measured as each cyclist pedaled at steady state with a cadence of 90 rpm and with a power output corresponding to approximately 90% of their ventilatory threshold (VT) (mean power output 203.3±20.8 W). After heart rate returned to baseline, V ˙ O 2 was measured again as the subject pedaled with a different anterior–posterior foot position, followed by another rest period and then V ˙ O 2 was measured at the final foot position. The key finding of this investigation was that V ˙ O 2 was not affected by the anterior–posterior foot position either for the group ( p = 0.311 ) or for any individual subject ( p⩾0.156). The V ˙ O 2 for the group was 2705±324, 2696±337, and 2747±297 ml/min for the forward, mid, and rear foot positions, respectively. The practical implication of these findings is that adjusting the anterior–posterior foot position on the pedal does not affect cycling economy in competitive cyclists pedaling at a steady-state power output eliciting approximately 90% of VT.

Snatch Technique of Collegiate National Level Weightlifters

Bar trajectory during weightlifting movements is related to the position of the body during the lift and the displacement of the feet during the drop-under phase. The purpose of this study was to examine anterior-posterior foot displacement and its relationship with performance in the snatch of collegiate weightlifters. Snatch attempts of men weightlifters from the 1998 U.S.A. Weightlifting Collegiate National Championships were analyzed for horizontal displacement of the feet by video analysis. Lifts were analyzed under 2 conditions: all lifts combined and the heaviest successful attempt for each lifter. Lifts (n = 74) were placed into 4 groups: forward displacement (FD, >2.5 cm); no displacement (ND, ±2.5 cm); rearward displacement (RD, >2.5 cm); and those that showed asymmetric (AS, >7 cm difference in right and left foot) displacement of the feet. Chi-square revealed no significant difference in success rate between groups for all attempts. No statistically significant differences were noted between groups in body mass to bar mass ratio or Sinclair formula for heaviest successful attempts. Results indicate that foot displacement did not significantly affect snatch success or lifting ability in collegiate national level lifters.

Snatch Technique of Collegiate National Level Weightlifters

Bar trajectory during weightlifting movements is related to the position of the body during the lift and the displacement of the feet during the drop-under phase. The purpose of this study was to examine anterior-posterior foot displacement and its relationship with performance in the snatch of collegiate weightlifters. Snatch attempts of men weightlifters from the 1998 U.S.A. Weightlifting Collegiate National Championships were analyzed for horizontal displacement of the feet by video analysis. Lifts were analyzed under 2 conditions: all lifts combined and the heaviest successful attempt for each lifter. Lifts (n = 74) were placed into 4 groups: forward displacement (FD, >2.5 cm); no displacement (ND, +/-2.5 cm); rearward displacement (RD, >2.5 cm); and those that showed asymmetric (AS, >7 cm difference in right and left foot) displacement of the feet. Chi-square revealed no significant difference in success rate between groups for all attempts. No statistically significant differences were noted between groups in body mass to bar mass ratio or Sinclair formula for heaviest successful attempts. Results indicate that foot displacement did not significantly affect snatch success or lifting ability in collegiate national level lifters.

Effects of Various Knee Angle and Foot Spacing Combinations on Performance in the Vertical Jump

Abstract Thirty young adult males performed the vertical jump (jump and reach) at knee angles of 65, 90, and 115 degrees while using lateral and anterior-posterior foot spacings of 0, 5, 10, and 15 inches. The preliminary position was held momentarily before jumping, and every subject jumped three times at each of the 48 combinations of knee angles and foot spacings. The average of the three jumps was considered the subject's score for each preliminary stance. The results revealed that: (a) knee angle, lateral foot spacing, and anterior posterior foot spacing exert independent effects on vertical jumping performance; and (b) the most effective preliminary stance seems to be one in which the knee angle is approximately 115° with the feet spread from 5 to 10 inches laterally and slightly in excess of 5 inches anteriorly-posteriorly.