Purpose. To assess the validity of a digitising time-motion analysis method for field-based sports and compare this to a notational analysis method using rugby union match play. Method. Five calibrated video cameras were located around a rugby pitch and one subject completed prescribed movements within each camera view. Running speeds were measured using photocell timing gates. Two experienced operators digitised video data (operator 1 on two occasions) to allow 2D reconstruction of the prescribed movements. Results. Accuracy for total distance calculated was within 2.1% of the measured distance. For intra- and inter-operator reliability, calculated distances were within 0.5% and 0.9% respectively. Calculated speed was within 8.0% of measured photocell speed with intra- and inter-operator reliability of 3.4% and 6.0%, respectively. For the method comparison, two 20 min periods of rugby match play were analysed for five players using the digitising method and a notational time-motion method. For the 20 min periods, overall mean absolute differences between methods for percentage time spent and distances covered performing different activities were 3.5% and 198.1 ± 138.1 m, respectively. Total number of changes in activity per 20 min were 184 ± 24 vs 458 ± 48 and work-to-rest ratio’s 10.0 / 90.0% and 7.3 / 92.7% for notational and digitising methods, respectively. Conclusion. The digitising method is accurate and reliable for gaining detailed information on work profiles of field sport participants and provides the applied researcher with richer data output than the conventional notational method.
|Number of pages||12|
|Journal||International Journal of Sports Physiology and Performance|
|Publication status||Published - 2006|
- rugby union