The Effect Of Treadmill Speed And Grade On Ice Hockey Skating Biomechanics

Abstract

Skating treadmills are used by ice hockey players to develop stride efficiency, power, and endurance. PURPOSE: Evaluate the effect of treadmill speed and grade on biomechanics. It was hypothesized that greater speeds and grades would elicit larger ranges of motion (ROM) and decrease stride time. METHODS: Seven competitive male ice hockey players (22.0 ± 0.6 y, 86.5 ± 4.4 kg, 1.82 ± 0.06 m) skated at five speed and grade conditions including 4.47 m·s-1 at 4% grade (10/4), 5.36 m·s-1 at 0% grade (12/0), 5.36 m·s-1 at 4% grade (12/4), 5.36 m·s-1 at 8% grade (12/8), and 6.26 m·s-1 at 4% grade (14/4). Left leg biomechanics were assessed using three-dimensional motion capture. Stride time was determined as the mean time between successive initial contacts of the left skate blade with the treadmill. Kinematics were normalized to percent of gait cycle. ROM was calculated as the difference between the maximum and minimum left hip and knee angles during the stance phase of the normalized kinematics. Separate repeated measures ANOVA and corrected, paired t-tests were used to assess the effect of condition. Significance was set to p < .05. RESULTS: A significant effect of condition on stride time (p < .001) was identified. Pairwise comparisons revealed that stride time was different for each condition (10/4 = .87 ± .07 s, 12/0 = 1.18 ± .13 s, 12/4 = .83 ± .06 s, 12/8 = .68 ± .05 s, 14/4 = .77 ±. 06 s). A significant effect of condition on hip sagittal plane ROM (p < .001) was identified. 12/0 (57.4 ± 4.4°) had smaller ROM than 12/4 (65.4 ± 6.6°), 12/8 (70.8 ± 7.0°), and 14/4 (66.6 ± 7.3°), 10/4 (63.0 ± 5.5°) had smaller ROM than 12/8, and 12/4 had smaller ROM than 12/8. A significant effect of condition on hip frontal plane ROM (p = .007) was also revealed, although no significant pairwise comparisons were identified (10/4 = 27.6 ± 4.4°, 12/0 = 31.3 ± 4.8°, 12/4 = 26.6 ± 4.6°, 12/8 = 23.3 ± 5.3°, 14/4 = 26.7 ± 4.0°). No effect of condition on knee sagittal plane ROM was revealed (p = .271; 10/4 = 44.6 ± 4.7°, 12/0 = 44.6 ± 4.9°, 12/4 = 44.8 ± 2.6°, 12/8 = 41.9 ± 3.0°, 14/4 = 42.3 ± 2.6°). CONCLUSIONS: In this small sample, increasing skating treadmill speed, grade, or both appears to decrease stride time, increase hip joint sagittal plane ROM, and have no effect on knee joint sagittal plane ROM. Results may aid in training program design and future ice hockey biomechanics research.