INTRODUCTION: In recent years the ski-touring (SKIALP) has acquired more popularity and SKIALP skiers have significantly improved their technical and physiological performances. The complex multiparametric environment conditions (air and snow temperature, track, techniques, gradients, materials, etc.) and the relatively recent development of the discipline, have hindered the performance of specific studies focused on SKIALP main biomechanical Parameters, similar to those performed in cross-country skiing (CCS) (Komi 1987, Smith 1990, Canclini 2000). Being convinced that SKIALP deserves biomechanical investigations, the purpose of our study is to investigate the kinematics of world elite SKIALP skiers on the treadmill and compare SKIALP kinematics patterns with CCS biomechanical parameters (Diagonal Stride-DS) measured during high level competition, simulated races and treadmill. METHOD: The first kind of data collection was performed since 1995 during WC CCS competition. A couple of digital camcorders (SONY 50 Hz) were located, in each races, on uphill section (9°). Dedicated Software for Video analysis was used (Baroni 1998). Calibration was performed by means of DLT method. A total of 10 skiers were analyzed during races. The same analysis method was applied on 4 Italian ski Team skiers engaged on a classical steady-state test by a trail with roller ski on a treadmill (2 m wide, 10° slope, 5 m/s velocity). Finally, 4 SKIALP elite skiers, were analyzed during a same test. The athletes performed their tests with their normal equipment (boots, skis and climbing skins) used on the snow. RESULTS: A set of specific kinematics parameters was measured for each athlete (tab. 1) and was reported as the mean value averaged on 2-3 movement cycles; angles-vs-angles plots were used to investigate individual coordination patterns. DISCUSSION/CONCLUSION: The SKIALP kinetics parameters measured in controlled trials on the treadmill were compared to corresponding data measured on CCS skiers on snow and on roller-ski on the treadmill. Despite such different experimental conditions, CT (cycle time) average values turned out to be quite similar (between 0.96± 0.07 s and 1.20± 0.07 s); on the contrary significant difference were found in the duration of the time-poling phase, which lasted around 50% of the CT in CCS skiers, and 66% in SKIALP athletes. Overall similar kinematics patterns of shoulders, elbows, poles inclination angles and lower body angles were observed among the examined populations, with a greater inter-subject variability in SKIALP than in CCS. The analysis seems to confirm that in al! examined cases and techniques the key phase in poling is represented by the pole plant (PP) and the related posture of upper and lower limbs. We found consistently an elbow angle at the PP around 90° without significant variations during the first part of the poling. This investigation represents the first, approximate, global biomechanical analysis of SKIALP locomotor patterns; obtained results need to be reinforced by additional data collection and analysis both on further subjects on treadmill and on the snow.
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