Kinematic Analysis of Alternate Stride Skating in Cross-Country Skiing

1988 ◽  
Vol 4 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Gerald A. Smith ◽  
Jill McNitt-Gray ◽  
Richard C. Nelson

Cross-country ski technique is undergoing rapid evolution. Alternate stride skating was the dominant technique during the 1985–86 racing season (double poling is synchronized with the “strong” side skate; no poling occurs with the “weak” side skate). High-speed films were made of elite male racers at the Holmenkollen World Cup races, Oslo, Norway (March 1986), skating up a 7° hill. Digitized data were filtered and processed to determine three-dimensional coordinates throughout a complete skating cycle. Ten skiers were analyzed, representing a range of performances. Over the 10-km race length, cycle rates for all skiers were similar; however, cycle lengths were significantly related to cycle velocity. The correlation between cycle velocity and length was r = 0.85. Ski angles were found to be asymmetrical. Weak-side ski angles were negatively related to cycle velocity; strong-side ski angles were similar for all skiers. Center of mass (CM) position throughout the cycle exhibited characteristic differences between faster and slower skiers. CM velocity vector direction was related to cycle velocity. Thus, faster skiers tended to maintain CM motion more nearly aligned with the forward direction.

2017 ◽  
Vol 12 (2) ◽  
pp. 211-217 ◽  
Author(s):  
Thomas Losnegard ◽  
Håvard Myklebust ◽  
Øyvind Skattebo ◽  
Hans Kristian Stadheim ◽  
Øyvind Sandbakk ◽  
...  

Purpose:In the double-poling (DP) cross-country-skiing technique, propulsive forces are transferred solely through the poles. The aim of the current study was to investigate how pole length influences DP performance, O2 cost, and kinematics during treadmill roller skiing.Methods:Nine male competitive cross-country skiers (24 ± 3 y, 180 ± 5 cm, 72 ± 5 kg, VO2max running 76 ± 6 mL · kg–1 · min–1) completed 2 identical test protocols using self-selected (84% ± 1% of body height) and long poles (self-selected + 7.5 cm; 88% ± 1% of body height) in a counterbalanced fashion. Each test protocol included a 5-min warm-up (2.5 m/s; 2.5°) and three 5-min submaximal sessions (3.0, 3.5, and 4.0 m/s; 2.5°) for assessment of O2 cost, followed by a selfpaced 1000-m time trial (~3 min, >5.0 m/s; 2.5°). Temporal patterns and kinematics were assessed using accelerometers and 2D video.Results:Long poles reduced 1000-m time (mean ± 90% confidence interval; –1.0% ± 0.7%, P = .054) and submaximal O2 cost (–2.7% ± 1.0%, P = .002) compared with self-selected poles. The center-of-mass (CoM) vertical range of displacement tended to be smaller for long than for self-selected poles (23.3 ± 3.0 vs 24.3 ± 3.0 cm, P = .07). Cycle and reposition time did not differ between pole lengths at any speeds tested, whereas poling time tended to be shorter for self-selected than for long poles at the lower speeds (≤3.5 m/s, P ≤ .10) but not at the higher speeds (≥4.0 m/s, P ≥ .23).Conclusions:DP 1000-m time, submaximal O2 cost, and CoM vertical range of displacement were reduced in competitive cross-country skiers using poles 7.5 cm longer than self-selected ones.


1989 ◽  
Vol 5 (2) ◽  
pp. 185-207 ◽  
Author(s):  
Gerald A. Smith ◽  
Richard C. Nelson ◽  
Adam Feldman ◽  
Jeffrey L. Rankinen

The alternate stride or V1 skate technique was the predominant skiing method used in the free technique races of the 1988 Calgary Games. High-speed films were recorded of two free technique races: the Men’s 50 K and the Ladies' 20 K. A moderate and a steep uphill were sites of the filming, and both temporal and kinematic analyses were made. Times for a complete skating cycle tended to decrease on the steep hill (cycle rate increased). Cycle temporal proportions shifted to longer poling and recovery phases while the skating phases shortened on the steeper terrain. Mean cycle velocities (CV), cycle lengths (CL), and cycle rates (CR) were determined. Differences in kinematic relationships were noted: Male skiers included both those who emphasized CL to maximize CV and those who emphasized CR; females were relatively more consistent in emphasis on CR. In either case, center of mass (CM) motions were related to CR and CL. Increased lateral motion of CM tended to increase CL while decreasing CR. Ski edging angles were negatively correlated; a sharply edged ski on one side was usually associated with the other ski being relatively flat. The relationship of glide to ski flatness suggests that many skiers might benefit from skating with both skis relatively flat.


2019 ◽  
Vol 51 (4) ◽  
pp. 760-772 ◽  
Author(s):  
THOMAS STÖGGL ◽  
OLLI OHTONEN ◽  
MASAKI TAKEDA ◽  
NAOTO MIYAMOTO ◽  
CORY SNYDER ◽  
...  

2017 ◽  
Vol 33 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Franziska Onasch ◽  
Anthony Killick ◽  
Walter Herzog

The aim of this study was to determine the effects of pole length on energy cost and kinematics in cross country double poling. Seven sub-elite male athletes were tested using pole sets of different lengths (ranging between 77% and 98% of participants’ body height). Tests were conducted on a treadmill, set to a 2% incline and an approximate racing speed. Poling forces, contact times, and oxygen uptake were measured throughout the testing. Pole length was positively correlated with ground contact time (r = .57, p < .001) and negatively correlated with poling frequency (r = −.48, p = .003). Pole length was also positively correlated with pole recovery time and propulsive impulse produced per poling cycle (r = .36, p = .031; r = .35, p = .042, respectively). Oxygen uptake and pole length were negatively correlated (r = −.51, p = .004). This acute study shows that increasing pole length for double poling in sub-elite cross country skiers under the given conditions seems to change the poling mechanics in distinct ways, resulting in a more efficient poling action by decreasing an athlete’s metabolic cost.


2012 ◽  
Vol 113 (6) ◽  
pp. 1385-1394 ◽  
Author(s):  
Johnny Nilsson ◽  
Fredrik Tinmark ◽  
Kjartan Halvorsen ◽  
Anton Arndt

2019 ◽  
Vol 14 (9) ◽  
pp. 1190-1199 ◽  
Author(s):  
Øyvind Skattebo ◽  
Thomas Losnegard ◽  
Hans Kristian Stadheim

Purpose: Long-distance cross-country skiers specialize to compete in races >50 km predominantly using double poling (DP). This emphasizes the need for highly developed upper-body endurance capacities and an efficient DP technique. The aim of this study was to investigate potential effects of specialization by comparing physiological capacities and kinematics in DP between long-distance skiers and skiers competing using both techniques (skating/classic) in several competition formats (“all-round skiers”). Methods: Seven male long-distance (32 [6] y, 183 [6] cm, 76 [5] kg) and 6 all-round (25 [3] y, 181 [5] cm, 75 [6] kg) skiers at high international levels conducted submaximal workloads and an incremental test to exhaustion for determination of peak oxygen uptake (VO2peak) and time to exhaustion (TTE) in DP and running. Results: In DP and running maximal tests, TTE showed no difference between groups. However, long-distance skiers had 5–6% lower VO2peak in running (81 [5] vs 85 [3] mL·kg−1·min−1; P = .07) and DP (73 [3] vs 78 [3] mL·kg−1·min−1; P < .01) than all-round skiers. In DP, long-distance skiers displayed lower submaximal O2 cost than all-round skiers (3.8 ± 3.6%; P < .05) without any major differences in cycle times or cyclic patterns of joint angles and center of mass. Lactate concentration over a wide range of speeds (45–85% of VO2peak) did not differ between groups, even though each workload corresponded to a slightly higher percentage of VO2peak for long-distance skiers (effect size: 0.30–0.68). Conclusions: The long-distance skiers displayed lower VO2peak but compensated with lower O2 cost to perform equally with the all-round skiers on a short TTE test in DP. Furthermore, similar submaximal lactate concentration and reduced O2 cost could be beneficial in sustaining high skiing speeds in long-duration competitions.


2004 ◽  
Vol 36 (Supplement) ◽  
pp. S14
Author(s):  
Gerald A. Smith ◽  
Johnny Nilsson ◽  
Bent Kvamme ◽  
Jarle Ure ◽  
Frank Ingjer

1996 ◽  
Vol 12 (1) ◽  
pp. 88-103 ◽  
Author(s):  
Gerald A. Smith ◽  
Jon B. Fewster ◽  
Steven M. Braudt

Olympic skiers in the women's 30-km race were analyzed as they double poled on a moderate downhill slope. Movement patterns of 20 skiers were analyzed 10 from a top finishing group and 10 from slower finishers in the bottom third of the field. Skiers in the faster group not only were faster overall in the race but were faster as they double poled through the site (6.75 vs. 6.43 m/s). Cycle length was significantly correlated with cycle velocity (r = .81). Trunk flexion and shoulder extension during poling were similar between groups; however, considerable variability of shoulder positioning was noted for both groups of skiers. Distinct shoulder-elbow-pole positioning differences were noted among skiers. Disadvantageous positionin» of the shoulder at the beginning of poling was related to poorer pole inclination during elbow extension. While many skiers in both fast and slow groups double poled with good positioning, others would benefit from greater shoulder flexion to maximize double poling performance.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256662
Author(s):  
Rune Kjøsen Talsnes ◽  
Guro Strøm Solli ◽  
Jan Kocbach ◽  
Per-Øyvind Torvik ◽  
Øyvind Sandbakk

The purpose of the present study was to investigate how various laboratory- and field-based tests predict on-snow cross-country (XC) skiing and roller-skiing performance. Thirty-three national-level male XC skiers (19.0±2.5 years, maximal oxygen uptake [VO2max] 70.8±4.7 mL·min-1·kg-1) performed a 13.6-km roller-ski skating competition tracked by a global positioning system (GPS), which together with individual distance International Ski Federation (FIS) points was used to assess their performance level. On separate days, time in a 6.4-km uphill running time-trial (RUN-TT) and 1.3-km uphill roller-ski double-poling time-trial (DP-TT) was measured in the field and performance indices determined while running and roller-ski skating in the laboratory. The mean finishing times for the RUN-TT and the DP-TT showed moderate to large correlations with distance FIS points and performance in the roller-ski skating competition (r = 0.56–0.72; all p<0.05). RUN-TT was more strongly correlated with distance FIS points than DP-TT (r = 0.72 versus 0.56; p<0.05). Performance indices and VO2max in incremental running and roller-ski skating in the laboratory showed large to very large correlations with distance FIS points and roller-skiing performance (r = 0.50–0.90; all p<0.05). Performance indices and VO2max in running tended to be more strongly correlated with roller-skiing performance than corresponding values obtained while roller-ski skating (all p<0.10). The present findings suggest that both laboratory performance indices and field-based performance tests provide valid predictions of XC skiing and roller-skiing performance in a heterogeneous group of male XC skiers, with test values obtained in running tending to be more strongly correlated with XC skiing performance than those found for technique-specific modalities on roller skis. However, more sophisticated and mode-specific testing might be required for more homogenous groups of elite XC skiers.


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