Relationship between local ski bending curvature, lean angle and radial force in alpine skiing

The deflection of the ski is a prerequisite for carved turns. The more the ski is edged, the more the ski has to deflect and the more radial force has to be realised in order to keep the whole edge in contact with the snow. To verify this relationship, local ski bending curvature, the lean angle and the radial force were correlated with each other. Characteristic curvature patterns as well as very large correlations (r > 0.7) between the variables were identified.Die Durchbiegung des Skis ist eine Voraussetzung für gecarvte Schwünge. Je stärker der Ski gekantet ist, desto mehr muss der Ski durchbiegen und desto mehr Radialkraft muss realisiert werden, um die gesamte Kante in Kontakt mit dem Schnee zu halten. Um diesen Zusammenhang zu verifizieren, wurden die lokale Skikrümmung, der Neigungswinkel und die Radialkraft miteinander korreliert. Es wurden sowohl charakteristische Krümmungsmuster als auch sehr große Korrelationen (r > 0,7) zwischen den Variablen festgestellt

Heel riser height and slope gradient influence the physiology of ski mountaineering—A laboratory study

In ski mountaineering it is the goal to reach the top of a mountain by sheer muscle force. The specific equipment (flexible boot, only toe fixated binding, and a skin on the ski to prevent from slipping backwards) enables the skier to move up the hill ergonomically, where the heel part of the binding offers a special adaptation possibility. The so-called riser height supports the heel standing height and can be adjusted to individually preferred settings. General recommendations suggest using lower heel support in flat ascents and higher heel support in steep ascents to maintain upright posture and lower the strain. Still, it remains unclear whether the application of riser height affects the physiological response during ski mountaineering. This study was designed to investigate the effects of riser height on physiological response during indoor ski mountaineering. Nineteen participants took part in the study and walked on a treadmill with ski mountaineering equipment. The three available riser heights (low, medium, and high) were applied randomized at 8%, 16%, and 24% gradient. Results show that global physiological measurements like heart rate (p = 0.34), oxygen uptake (p = 0.26) or blood lactate (p = 0.38) values were not affected by changes in riser height. But local measurements of muscle oxygen saturation were affected by the riser height. Additionally comfort and rating of perceived exertion were also prone to changes in riser height. These results suggest differences on local measurements and perceived parameters, while global physiological measurements did not change. The results are in line with the existing recommendations but need to be confirmed in an outdoor setting as well

Assessment of physiological parameters in competitive ski mountaineering

eingereicht von Lasshofer Michael, BScLiteraturverzeichnis: Blatt 34-36Universität Salzburg, Masterarbeit, 2019(VLID)507218

Relationship between local ski bending curvature, lean angle and radial force in alpine skiing

The deflection of the ski is a prerequisite for carved turns. The more the ski is edged, the more the ski has to deflect and the more radial force has to be realised in order to keep the whole edge in contact with the snow. To verify this relationship, local ski bending curvature, the lean angle and the radial force were correlated with each other. Characteristic curvature patterns as well as very large correlations (r > 0.7) between the variables were identified.Die Durchbiegung des Skis ist eine Voraussetzung für gecarvte Schwünge. Je stärker der Ski gekantet ist, desto mehr muss der Ski durchbiegen und desto mehr Radialkraft muss realisiert werden, um die gesamte Kante in Kontakt mit dem Schnee zu halten. Um diesen Zusammenhang zu verifizieren, wurden die lokale Skikrümmung, der Neigungswinkel und die Radialkraft miteinander korreliert. Es wurden sowohl charakteristische Krümmungsmuster als auch sehr große Korrelationen (r > 0,7) zwischen den Variablen festgestellt

Relationship between local ski bending curvature, lean angle and radial force in alpine skiing

The deflection of the ski is a prerequisite for carved turns. The more the ski is edged, the more the ski has to deflect and the more radial force has to be realised in order to keep the whole edge in contact with the snow. To verify this relationship, local ski bending curvature, the lean angle and the radial force were correlated with each other. Characteristic curvature patterns as well as very large correlations (r > 0.7) between the variables were identified.Die Durchbiegung des Skis ist eine Voraussetzung für gecarvte Schwünge. Je stärker der Ski gekantet ist, desto mehr muss der Ski durchbiegen und desto mehr Radialkraft muss realisiert werden, um die gesamte Kante in Kontakt mit dem Schnee zu halten. Um diesen Zusammenhang zu verifizieren, wurden die lokale Skikrümmung, der Neigungswinkel und die Radialkraft miteinander korreliert. Es wurden sowohl charakteristische Krümmungsmuster als auch sehr große Korrelationen (r > 0,7) zwischen den Variablen festgestellt

Technique-Dependent Relationship between Local Ski Bending Curvature, Roll Angle and Radial Force in Alpine Skiing

Skiing technique, and performance are impacted by the interplay between ski and snow. The resulting deformation characteristics of the ski, both temporally and segmentally, are indicative of the unique multi-faceted nature of this process. Recently, a PyzoFlex® ski prototype was presented for measuring the local ski curvature (w″), demonstrating high reliability and validity. The value of w″ increases as a result of enlargement of the roll angle (RA) and the radial force (RF) and consequently minimizes the radius of the turn, preventing skidding. This study aims to analyze segmental w″ differences along the ski, as well as to investigate the relationship among segmental w″, RA, and RF for both the inner and outer skis and for different skiing techniques (carving and parallel ski steering). A skier performed 24 carving and 24 parallel ski steering turns, during which a sensor insole was placed in the boot to determine RA and RF, and six PyzoFlex® sensors were used to measure the w″ progression along the left ski (w1−6″). All data were time normalized over a left-right turn combination. Correlation analysis using Pearson’s correlation coefficient (r) was conducted on the mean values of RA, RF, and segmental w1−6″ for different turn phases [initiation, center of mass direction change I (COM DC I), center of mass direction change II (COM DC II), completion]. The results of the study indicate that, regardless of the skiing technique, the correlation between the two rear sensors (L2 vs. L3) and the three front sensors (L4 vs. L5, L4 vs. L6, L5 vs. L6) was mostly high (r > 0.50) to very high (r > 0.70). During carving turns, the correlation between w″ of the rear (w1−3″) and that of front sensors (w4−6″) of the outer ski was low (ranging between −0.21 and 0.22) with the exception of high correlations during COM DC II (r = 0.51–0.54). In contrast, for parallel ski steering, the r between the w″ of the front and rear sensors was mostly high to very high, especially for COM DC I and II (r = 0.48–0.85). Further, a high to very high correlation (r ranging between 0.55 and 0.83) among RF, RA, and w″ of the two sensors located behind the binding (w2″,w3″) in COM DC I and II for the outer ski during carving was found. However, the values of r were low to moderate (r = 0.04–0.47) during parallel ski steering. It can be concluded that homogeneous ski deflection along the ski is an oversimplified picture, as the w″ pattern differs not only temporally but also segmentally, depending on the employed technique and turn phase. In carving, the rear segment of the outer ski is considered to have a pivotal role for creating a clean and precise turn on the edge