INTRODUCTION: The physiology and mechanics of single-leg skiers are not well understood; there is one previous study on this group of skiers. Single-leg skiers undergo greater knee extension and recruitment of biceps femoris for balance during alpine skiing, but trunk kinematics and muscle recruitment have not been extensively studied 1. The purpose of this study is to identify kinematic and muscular activation differences between single-leg skiers and non-disabled skiers. METHODS: Delsys Trigno sEMG and XSENS were used to monitor a professional single-leg skier`s and an expert non-disabled skier`s muscular activity and joint kinematics through ten equally spaced turns. sEMG was assessed unilaterally on Rectus Femoris (RF), Biceps Femoris (BF), Vastus Lateralis (VL), Vastus Medialis (VM), Gluteus Medius (GMD), Medial Gastrocnemius (MG), Peroneus Longus (PL) and Tibialis Anterior (TA) 2. XSENS motion capture assessed trunk, hip, and knee kinematics. RESULTS: A decreased knee joint flexion range of motion (ROM) of 39.9°, exaggerated knee joint internal/external rotation of 27.4°, and an increased lateral trunk flexion ROM of 46.1° in the single-leg skier compared to 99.6°, 15.4°, and 39.9° in the two-legged skier, respectively. The single-leg skier had a higher % MVIC for VL, VM, PL, and BF than the two-legged skier. DISCUSSION/CONCLUSION: The single-leg skier recruits the lower leg muscles to stabilize the ankle and knee joint and compensates for a decreased ROM in the knee with increased movement in the trunk. These findings are in line with previous research and add a quantitative measure of trunk kinematics 1. Subsequent investigations should aim to measure trunk muscle activation and identify the role of the upper body for balance and control during alpine skiing.
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