|
Affiliation
|
Centre for Exercise and Sport Science, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia. |
|
Abstract
|
CONTEXT: Accelerometer peak impact accelerations are being used to measure player physical demands in contact sports. However, their accuracy to do so has not been ascertained.
PURPOSE: To compare peak impact acceleration data from an accelerometer contained within a wearable tracking device with a three dimensional motion analysis (MA) system during tackling and bumping.
METHODS: Twenty-five semi-elite rugby athletes wore a tracking device containing a 100 Hz triaxial accelerometer (MininmaxX S4, Catapult Innovations, Australia). A single retro-reflective marker was attached to the device with its position recorded by a 12-camera MA system during three physical collision movements (tackle bag, bump pad and tackle drill; n = 625). The accuracy, effect size, agreement, precision and relative errors for each comparison were obtained as measures of accelerometer validity.
RESULTS: Physical collision peak impact accelerations recorded by the accelerometer overestimated (mean bias 0.60 g) those recorded by the MA system (P < 0.01). Filtering the raw data at a 20 Hz cut-off improved the accelerometer's relationship with MA data (mean bias 0.01 g; P > 0.05). When considering the data in nine magnitude bands, the strongest relationship with the MA system was found in the 3.0 g or less band and the precision of the accelerometer tended to reduce as the magnitude of impact acceleration increased. Of the three movements performed, the tackle bag movement displayed the greatest validity with MA.
CONCLUSIONS: The findings indicate that the MinimaxX S4 accelerometer can accurately measure physical collision peak impact accelerations when data were filtered at a 20 Hz cut-off frequency. As a result, accelerometers may be useful to measure physical collisions in contact sports.
Language: en |