Understanding successful and unsuccessful landings of aerial maneuver variations in professional surfing.

Although performing aerial maneuvers can increase wave score and winning potential in competitive surfing, the critical features underlying successful aerial performance have not been systematically investigated. This study aimed to analyze highly skilled aerial maneuver performance and to identify the critical features associated with successful or unsuccessful landing. Using video recordings of the World Surf League's Championship Tour, every aerial performed during the quarterfinal, semifinal, and final heats from the 11 events in the 2015 season was viewed. From this, 121 aerials were identified with the Frontside Air (n = 15) and Frontside Air Reverse (n = 67) being selected to be qualitatively assessed. Using chi-squared analyses, a series of key critical features, including landing over the center of the surfboard (FS Air χ2  = 14.00, FS Air Reverse χ2  = 26.61; P < .001) and landing with the lead ankle in dorsiflexion (FS Air χ2  = 3.90, FS Air Reverse χ2  = 13.64; P < .05), were found to be associated with successful landings. These critical features help surfers land in a stable position, while maintaining contact with the surfboard. The results of this study provide coaches with evidence to adjust the technique of their athletes to improve their winning potential.

Are the feet of obese children fat or flat? Revisiting the debate.

OBJECTIVE: There is debate as to the effects of obesity on the developing feet of children. We aimed to determine whether the flatter foot structure characteristic of obese primary school-aged children was due to increased medial midfoot plantar fat pad thickness (fat feet) or due to structural lowering of the longitudinal arch (flat feet). METHODS AND PROCEDURES: Participants were 75 obese children (8.3 ± 1.1 years, 26 boys, BMI 25.2 ± 3.6 kg m(-2)) and 75 age- and sex-matched non-obese children (8.3 ± 0.9 years, BMI 15.9 ± 1.4 kg m(-2)). Height, weight and foot dimensions were measured with standard instrumentation. Medial midfoot plantar fat pad thickness and internal arch height were quantified using ultrasonography. RESULTS: Obese children had significantly greater medial midfoot fat pad thickness relative to the leaner children during both non-weight bearing (5.4 and 4.6 mm, respectively; P<0.001) and weight bearing (4.7 and 4.3 mm, respectively; P < 0.001). The obese children also displayed a lowered medial longitudinal arch height when compared to their leaner counterparts (23.5 and 24.5 mm, respectively; P = 0.006). CONCLUSION: Obese children had significantly fatter and flatter feet compared to normal weight children. The functional and clinical relevance of the increased fatness and flatness values for the obese children remains unknown.

Does obesity influence foot structure in prepubescent children?

OBJECTIVE: This study examines the relationship between obesity and foot structure in prepubescent children. DESIGN: Field-based, experimental data on BMI (body mass index) and foot structure were collected for 431 consenting children from 18 randomly selected primary schools. SUBJECTS: Of the 431 participants, 62 obese (BMI>95th percentile) and 62 non-obese (10th percentile90th percentile) children (age = 8.5+/-0.5 y) were selected. MEASUREMENTS: Height and weight were measured to calculate BMI. Static weight-bearing footprints for the right and left foot of each subject were then taken using a pedograph to calculate the Footprint Angle and the Chippaux-Smirak Index as representative measures of the surface area of the foot in contact with the ground. RESULTS: A significant difference was found between the Footprint Angle of the obese and non-obese subjects for both the left (t = 3.663; P<0.001) and right (t = 3.742; P<0.001) feet whereby obese subjects displayed a reduced angle. Chippaux-Smirak Index scores were also significantly different for both the left (t = -6.362; P<0.001) and right (t=-5.675; P<0.001) feet between the two subject groups where a greater score for the obese subjects was evident. A decreased footprint angle and an increased Chippaux-Smirak Index are characteristic of structural foot changes that have been associated with compromised foot function. CONCLUSIONS: Excess body mass appears to have a significant effect on the foot structure of prepubescent children whereby young obese children display structural foot characteristics which may develop into problematic symptoms if excessive weight gain continues. Further investigation into possible consequences, particularly any effects on foot function, is warranted.