DATASET FOR STUDY: The Influence of Hip Angle on trunk muscle activation during simulated hiking in ILCA Class sailors: a pilot study

The purpose of the study was to determine how different hip angles in the hiking position on a sailing simulator affect trunk muscle activation in Slovenian ILCA class sailors. Ten competitive sailors participated in the study. Each participant first performed maximal voluntary contraction measurements for selected trunk muscles and then completed two trials on the simulator at three hip angles: extended, semi-flexed, and flexed. Surface electromyography was used to assess rectus abdominis, external oblique, internal oblique, and erector spinae activation, with values normalized to maximal voluntary contraction. Hip angle had a significant effect on rectus abdominis activation (59.3 ± 18.5%, 30.8 ± 14.2%, and 14.9 ± 10.7% maximal voluntary contraction for extended, semi-flexed, and flexed positions, respectively; p < 0.001), external oblique activation (46.2 ± 17.2%, 31.9 ± 8.9%, and 21.7 ± 8.5% MVC; p = 0.002), and internal oblique activation (24.9 ± 7.6%, 15.5 ± 6.7%, and 13.8 ± 8.4% MVC; p = 0.002). In contrast, erector spinae activation remained low across conditions (5.4 ± 4.2%, 3.6 ± 2.0%, and 3.2 ± 2.0% MVC) and did not differ significantly between hip angles after correction for sphericity (p = 0.082). These findings indicate that greater hip extension during simulated hiking increases abdominal muscle activation, particularly in the rectus abdominis and external oblique muscles, while erector spinae involvement remains limited.