VISUAL DETECTION OF RESPONSE TIME IN ATHLETICS: A “GOLD STANDARD”?

The response time (RT) in the sprint start in athletics is determined automatically from sensors on the blocks but the final decision on whether an athlete is disqualified is determined by visual inspection of the sensor data. This study explored the level of uncertainty of the visual detection of athletes’ RT in the sprint start. Fifteen sprinters performed six sprint starts while forces from the front block, rear block and hands were recorded. Two experimenters performed visual RT detection on two consecutive occasions using two sizes for the analysis window. Intra- and inter-reliability analysis indicated that the mean level of uncertainty of the visual detection was approximately 20 ms for the starting block data. More research is needed to formally assess the precision of the visual detection, which may result in changes in the current false start regulation

MAPPING OUT THE RESPONSE SEQUENCE OF THE SPRINT START

Establishing the limits of sprint start response time (SSRT) requires the mapping of the muscular sequence of activation and mechanical response delays and was the aim of the current study. Sprint start performance of 15 sprinters was examined with kinematic, EMG, and block force data collected. A general muscle activation sequence was identified, with both deltoid muscles, the rear leg rectus femoris, and the rear leg tibialis anterior the first muscles to increase activation from the set position. With ankle dorsiflexion the initial motion during the block push, examining the period between tibialis anterior muscle onset and block force onset is critical for quantifying mechanical response delays . Estimates of this delay period were as low as 7 ms which has implications for our understanding of the minimum SSRT a sprinter can legally produce

Contribution of new start information system prototype to the false start detection in athletics

This study aimed at comparing a prototype of a new Start Information System (SIS) with a World Athletics (WA) certified SIS which was used in competition. Twenty sprinters performed sprints under simulated race conditions. Response time (RT) was recorded by the WA certified SIS and the new SIS prototype based on a custom force plate and a new event detection algorithm to assess RT as the onset of arm force reaction. The mean value from RT recorded by the new SIS prototype for trials for which the RT given by the WA certified SIS were ranged between 100 ms and 119 ms (RT WA 100-119 ms) was 0.047±0.019 s. This result highlighted RTWA 100-119 ms were probably false start according to the theoretical minimum auditory RT, despite being valid by the current WA regulation. The revisited new SIS prototype technologies were more appropriate to detect false start in athletic