This study tested the hypothesis that the increase in rating of perceived exertion (RPE) predicts the duration of exercise to exhaustion during exercise in hot conditions. Seven subjects performed five cycling trials in an environmental chamber at temperatures of 15 degrees C (C) and 35 degrees C (H). The cool trials were performed at intensities of 65 and 70% and the hot trials at 55, 60 and 65%. RPE, rectal and skin temperature were measured during trials. Duration to fatigue was significantly shorter in H65 and C70 than H60, C65 and H55 (P < 0.05). RPE rose linearly throughout each trial and the rate of increase in RPE was significantly faster in H65 and C70 than H55 (P < 0.05). There was an inverse linear relationship between trial duration and rate of increase in RPE (r = 0.83). Rectal temperature increased linearly throughout the trial and correlated significantly with RPE (r = 0.92). This study shows that the rate of increase in RPE predicts the duration of exercise to exhaustion at a constant power output in different environmental conditions.

This study aimed to assess changes in bowling technique and lumbar load over the course of a bowling spell in adolescent fast bowlers, and to investigate the relationship between lumbar loads during fast bowling and kinematic factors which have previously been associated with low back injury. Three-dimensional motion analysis was carried out on forty participants who performed an 8-over bowling spell. There were no significant changes in bowling technique or lumbar loads over the course of the spell. Bowling with a more extended front knee, faster ball release speed and increased shoulder counter-rotation were related to increased lumbo-pelvic loading - in particular peak transverse plane rotation moments and anterior-posterior shear forces. These lumbar loads may be a factor in low back injury aetiology and future studies should investigate the relationship between lumbar loading, injury incidence and other risk factors.

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This study aimed to assess variability in lumbo-pelvic forces and moments during a dynamic high-impact activity (cricket fast bowling) when calculated using different body segment parameters (BSPs). The first three BSPs were estimated using methods where the trunk was divided into segments according to nonspinal anatomical landmarks. The final approach defined segment boundaries according to vertebral level. Three-dimensional motion analysis data from nine male cricketers’ bowling trials were processed using the four BSPs. A repeated-measures analysis of variance revealed no significant effect on peak lumbo-pelvic forces. However, the segmentation approach based on vertebral level resulted in significantly larger peak flexion and lateral flexion moments than the other BSP data sets. This has implications for comparisons between studies using different BSPs. Further, given that a method defined with reference to vertebral level more closely corresponds with relevant anatomical structures, this approach may more accurately reflect lumbar moments.