Design and validation of a portable, inexpensive and multi-beam timing light system using the Nintendo Wii hand controllers

Objectives: Commercial timing light systems (CTLS) provide precise measurement of athletes running velocity, however they are often expensive and difficult to transport. In this study an inexpensive, wireless and portable timing light system was created using the infrared camera in Nintendo Wii hand controllers (NWHC). Design: System creation with gold-standard validation. Method: A Windows-based software program using NWHC to replicate a dual-beam timing gate was created. Firstly, data collected during 2 m walking and running trials were validated against a 3D kinematic system. Secondly, data recorded during 5 m running trials at various intensities from standing or flying starts were compared to a single beam CTLS and the independent and average scores of three handheld stopwatch (HS) operators. Intraclass correlation coefficient and Bland–Altman plots were used to assess validity. Absolute error quartiles and percentage of trials in absolute error threshold ranges were used to determine accuracy. Results: The NWHC system was valid when compared against the 3D kinematic system (ICC = 0.99, median absolute error (MAR) = 2.95%). For the flying 5 m trials the NWHC system possessed excellent validity and precision (ICC = 0.97, MAR < 3%) when compared with the CTLS. In contrast, the NWHC system and the HS values during standing start trials possessed only modest validity (ICC < 0.75) and accuracy (MAR > 8%). Conclusions: A NWHC timing light system is inexpensive, portable and valid for assessing running velocity. Errors in the 5 m standing start trials may have been due to erroneous event detection by either the commercial or NWHC-based timing light systems.