Trunk muscle loading and hip angle adjustments during simulated hiking in International Laser Class Association sailors: implications for athletic conditioning, Нагрузка на мышцы туловища и корректировка угла наклона тазобедренного сустава во время имитации пешего перехода у яхтсменов Международной ассоциации лазерных яхт: значения для спортивной подготовки, Навантаження на м'язи тулуба та коригування кута нахилу кульшового суглоба під час імітації пішого переходу у яхтсменів Міжнародної асоціації лазерних яхт: значення для спортивної підготовки

<jats:p>Background and purpose The hiking position is a fundamental technique in International Laser Class Association dinghy sailing that requires prolonged trunk muscle activation to counteract external heeling forces. However, the influence of hip angle on trunk muscle activation during hiking has not been sufficiently investigated. From an applied perspective, clarifying this relationship could help coaches and strength and conditioning specialists use hip-angle adjustments to target different trunk-loading demands during simulator-based training. Therefore, the purpose of this pilot study was to determine how different hip angles in the hiking position on a sailing simulator affect trunk muscle activation in Slovenian sailors competing in International Laser Class Association classes. Material and methods Ten competitive International Laser Class Association sailors participated in the study. Maximal voluntary contractions of selected trunk muscles were recorded before testing. Participants then performed two trials on a sailing 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 each participant’s maximal voluntary contraction. Results Hip angle had a significant effect on rectus abdominis activation (59.3 ± 18.5%, 30.8 ± 14.2%, and 14.9 ± 10.7% of maximal voluntary contraction for the extended, semi-flexed, and flexed positions, respectively; p &lt; 0.001), external oblique activation (46.2 ± 17.2%, 31.9 ± 8.9%, and 21.7 ± 8.5% of maximal voluntary contraction; p = 0.002), and internal oblique activation (24.9 ± 7.6%, 15.5 ± 6.7%, and 13.8 ± 8.4% of maximal voluntary contraction; p = 0.002). Erector spinae activation remained low across all conditions (5.4 ± 4.2%, 3.6 ± 2.0%, and 3.2 ± 2.0% of maximal voluntary contraction) and did not differ significantly between hip angles (p = 0.082). Conclusions Greater hip extension during a simulated hiking position was associated with increased activation of the rectus abdominis, external oblique, and internal oblique muscles, whereas erector spinae activation remained low. These acute responses indicate that hip angle can be used as a practical loading variable when planning hiking-simulator technique and conditioning sessions.</jats:p>