I7-1　Development of bobsleigh shoe in preparation for the 2018 Pyeongchang Winter Olympics

Abstract

In this study we aimed to provide necessary basic data by elucidating the relationship between toe spring angle(TSA) and start sprint lap time in bobsleigh shoes, in order to develop Korean-specific bobsledding shoes. The participants of the present study consisted of 6 reserve members of the Korean national bobsleigh team who received sufficient explanation on the objective of the study and volunteered to participate. The bobsleigh shoes used in the experiment were prototypes developed by "T" Corporation, which consisted of types A, B, and C with TSAs of 30, 35, and 40, respectively. To analyze the time taken during the start, digital run-time meters (SR-500SP, Seed Tech, Korea) were set up at intervals of 0-5, 5-10, and 0-10 m for data collection. Moreover, to measure the fore foot bending angle(FBA) during the bobsleigh start motion, a high-speed camera (S-pri, AOS, Switzerland) was set up on the outside of the track, approximately 5 m from the start line, for collection of data at a rate of 1,000 frames/sec. For the FBA measurements, 7 markers (points 1-7) were attached on the sides of the outsole in the forefoot and midfoot areas. The internal angle created by lines connecting 3 points in the central area of the 7 attached markers was defined as a single angle and analyzed accordingly. The results of the analysis of the time required in the bobsleigh start stage showed significant differences between the shoes at the interval of 5-10 m, with post hoc test results indicating a statistically significant difference between the type C and A shoes (*p < .05). Moreover, the results of the analysis of FBA in the bobsleigh start stage showed significant differences between the shoes at angles 2, 3, 4, and 5. The post hoc test results indicated significant differences between types B and C at angle 2 (**p < .01); types A and C at angle 3 (**p < .01); types A and C, and types B and C at angle 4 (***p < .001); and types A and B, and types B and C at angle 5 (**p < .01). As running speed increases, FBA should also increase, but excessive forefoot bending can lead to plantar fasciitis injury and increased fatigue. Meanwhile, excessive bending restriction can reduce the efficiency of using the ground reaction force and cause limited range of motion, which act as obstacles to sports performance. Type C shoes were designed to have a TSA of 40; as such, they induced the most suitable FBA at angles 3 and 4, which correspond to the metatarsal joint, in providing the bending moment for the driving force of the bobsleigh athletes, which contributed to the shortening of the time record in the start stage.

Peculiarities of Muscle-Tendon Mechanics and Energetics in Elite Athletes in Various Sports

“…A standard bobsled race may be divided into three phases: start, race and finish [50]. Acceleration and high speed at the end of the start phase are crucial for high bob speed during a race and a better overall result [50,51].…”

“…A standard bobsled race may be divided into three phases: start, race and finish [50]. Acceleration and high speed at the end of the start phase are crucial for high bob speed during a race and a better overall result [50,51]. At the start phase, athletes must start the race by pushing the bob within 60 seconds after the start signal and run at full speed about 55 m. The start and push phases last for only 6 seconds, but they are the most important for the final result [52].…”