Endurance Times of Trunk Muscles in Male Intercollegiate Rowers in Hong Kong

Chan RH. Endurance times of trunk muscles in male intercollegiate rowers in Hong Kong.ObjectivesTo establish isometric endurance times of trunk muscles and their ratios in a group of healthy intercollegiate rowers in Hong Kong for clinical assessment reference, and to compare the trunk endurance profile of the rowers in the current study with that of nonrowers in another study.DesignIsometric endurance times were measured in 4 different positions in a cross-sectional manner. A subset of 5 subjects was tested 3 times 2 days and 1 week apart to evaluate reliability.SettingSports medicine department of a national sports institute.ParticipantsThirty-two subjects selected from a group of 42 male intercollegiate rowers reported to have more than 6 months of rowing experience and without history of low back pain.InterventionsNot applicable.Main Outcome MeasuresTrunk muscle endurance times in seconds and ratios of endurance times normalized to that of the extensor muscle.ResultsThe trunk flexor (mean ± standard deviation, 176.56±88.58s) had the best endurance times among all the trunk muscles tested (extensor mean, 114.28±34.62s; left lateral flexor mean, 94.53±32.97s; right lateral flexor mean, 98.13±41.38s). No significant difference was found between the left and right lateral flexors (P<.05). The lateral flexor and the flexor endurance times were 85% and 154% of that of the extensor, respectively. The testing protocol in this group of rowers showed good to excellent reliability (intraclass correlation coefficient range, .76–.93).ConclusionsIntercollegiate rowers in Hong Kong have better endurance in their trunk flexor than the extensor; the lateral flexors are of similar endurance capacity. These findings are different from the endurance profile reported for nonrowers in a previous study. Such differences should be considered when evaluating trunk endurance times in rowers for rehabilitation and training.