(70) Single Leg Lateral and Horizontal Loaded Jump Testing: Reliability and Correlation with Long Track Sprint Speed Skating Performance

Purpose:  This study examined the intra-day reliability of two novel unilateral loaded jump protocols designed for long track speed skaters. SUBJECTS: Highly trained (n=26), national level athletes performed single leg jumps with a horizontal robotic resistance across three external load conditions (10 N, 7.5% of body mass, 15% of body mass) using their dominant limb. Jumps were performed in both the horizontal (Jump_Horz) and lateral (Jump­_Lat) direction to replicate the body position and line of force application observed during the running and gliding phases of on-ice acceleration. Subjects completed two consecutive trials of the same jump protocol to examine the intra-day reliability of the peak velocity (PV) achieved for each loading condition.

Results:  PV across each jump type and loading condition had good reliability (ICC > 0.8, CV < 5%). Significant positive relationships (r=0.5-0.8, P < 0.05; n=22) were observed between all jump conditions and on-ice sprint race split times obtained including 100 m (Figure 1), 400 m and 500m.

Conclusions:  Our results indicate that unilateral loaded jump tests are reliable in speed skating athletes and may help practitioners diagnose and monitor lower limb maximal muscle power capacity in a sport specific manner. PRACTICAL APPLICATIONS: The results of this study suggest that both the Jump­_Lat and Jump_Horz loaded jump protocols used in the present study were reliable and showed a strong correlation with long track speed skating performance. Practitioners seeking to use linear modelling approaches during resisted unilateral jumping must determine how to sufficiently load the jump without degrading movement kinematics or focus on PV across load conditions as an outcome measure rather than relying on LV parameters. Directions of future research may be to implement these tests in other skating populations, compare results with standard bilateral jump assessments, and move towards on-ice measurement tools that allow running and gliding performance to be assessed separately.

Acknowledgements: This study was supported by the Canadian Sport Institute Calgary, the Olympic Oval at the University of Calgary, Speed Skating Canada, the Killam Foundation, and the Canadian Institutes of Health Research (CIHR: 950-200955).