The influence of bowling velocity on movement variability in experienced older aged lawn bowlers

This project examined the movement strategies adopted by highly experienced older aged lawn bowlers when performing Draw and Drive deliveries.

Cross-sectional.

Twenty five experienced (10.2 ± 7.8 years) older aged lawn bowlers (67.3 ± 7.0 years) who play lawn bowls at least once per week volunteered to participate in this study. Participants performed 10 Draw and Drive deliveries at a target positioned 23 m away while standing on two force platforms (600 Hz), while an infrared motion capture system (200 Hz) recorded phases times and both foot and bowl positioning. Normalised root mean square (NoRMS) analyses was used to assess the bowl path consistency during the delivery phase. Correlation analyses assessed for relationships between age and experience and the spatiotemporal variables, with paired t-tests and effect size (ES) analyses used to examine differences between delivery types.

None of the spatiotemporal or NoRMS data achieved more than low correlations with either age or playing experience (R² < 0.2). Although bowl release velocities were significantly slower for the Draw 5.25 ± 0.72 m/s than for the Drive deliveries 6.40 ± 0.97 m/s (p < 0.001, ES = 1.96) there were limited changes in any of the spatiotemporal variables. NoRMS data remained largely unchanged between Draw (5.10 ± 1.65) and Drive (5.07 ± 1.49, p = 0.925, ES = 0.02) deliveries.

These highly experienced lawn bowlers are adapting their technique to the different task demands of the two delivery types without altering their specific movement strategies.