High Caliber vs Low Caliber Skaters
Skating can be described as a bi-phasic activity involving both a support phase and a swing phase (Garrett & Kirkendall, 2000; Marino, 1977; Upjohn, Turcotte, Pearsall, & Loh, 2008). The support phase may be further subdivided into both single leg support, corresponding to glide, and double support corresponding to push off. Propulsion occurs during the first half of single leg support and commences during double leg support as the hip is abducted and externally rotated and the knee is extended (Garrett & Kirkendall, 2000; Marino, 1977). Skating is a skill, and the differences between elite and non-elite skaters have been investigated by a number of researchers (Budarick et al., 2018; McPherson, Wrigley, & Montelpare, 2004; Shell et al., 2017; Upjohn et al., 2008)
The major differences in performance between elite and non-elite players has primarily focused on acceleration of the players center of mass. The ice provides a unique environment in which the coefficient of friction is low ranging between .003-.007(Garrett & Kirkendall, 2000). This environment precludes anteroposterior force production (Budarick et al., 2018; Shell et al., 2017). In order to overcome inertia and accelerate, strength is needed to create pressure between the ice and the skate blade. Researchers have found significant differences between off-ice lower body strength tests and acceleration ability. Elite players could jump significantly further in the single leg broad jump than lower caliber players (Budarick et al., 2018; Shell et al., 2017; Upjohn et al., 2008). It appears that higher levels of strength may differentiate elite from non-elite skaters.
Step width is the measurement from the ipsilateral foot relative to the contralateral foot during propulsion. Large amounts of hip abduction are needed in conjunction with large step widths to improve acceleratory ability on the ice (Budarick et al., 2018; McPherson et al., 2004; Shell et al., 2017). It was determined that men had larger step widths and ten degrees more abduction at the hip than women players. In addition men exhibited increase hip flexion amplitudes during stance and increase knee flexion angles. This resulted in men attaining higher velocities (8.4 m/s vs 7.5 m/s) during a fifteen meter, blue line to blue line skate (Shell et al., 2017).
Angular displacement (range of motion) is another critical factor differentiating elite from non-elite skaters. Elite skaters display larger joint amplitudes. When comparing elite vs non-elite skaters on a skating treadmill, elite skaters had greater stride lengths, and increased range of motion at the hip and knee joints respectively (Upjohn et al., 2008). Range of motion continues to increase as the player moves from a run to glide motion with knee angles increasing approximately ten degrees from step one to step three (Lafontaine, 2007). The ankle is also displays more amplitude during acceleration as elite skaters had approximately 17.6 more degrees of plantarflexion than non-elite skaters. The authors suggested that this may be due to insufficient strength needed to overcome the rigidity of the skate boot in lower caliber players (McPherson et al., 2004; Stull, Philippon, & LaPrade, 2011).
Finally, stride rate has been found to further separate acceleration ability between elite vs non-elite skaters. Low trajectory angle, short single support time, and the foot placed below the hip prior to propulsion are all important aspects that separate average from elite players (Marino, 1977). While skating at easy, moderate and high velocities researchers have found a negative correlation between stride rate and both single and double leg support times. In other words, as speeds increase support times decrease and stride rates increase. This reinforces the concept that at higher speeds the number of times the force of propulsion is applied may be more important than the force at each propulsion (Marino, 1977; Wu, Pearsall, Russell, & Imanaka, 2016). Stride rates are typically much greater for higher caliber players (McPherson et al., 2004; Stidwill, Pearsall, & Turcotte, 2010; Upjohn et al., 2008; Wu et al., 2016).
The significant differences between elite and non-elite players can be seen in off-ice strength measures, as elite players tend to be stronger than non-elite (Shell et al, ’17, Budarick et al, ’18). Step widths, as elite players possess wider step distances (Shell et al, ’17, Budarick et al, ’18, Lafontaine et al, ’07), angular displacements and stride rate (Lafontaine et al, ’07, Shell et al ’17, Budarick et al, ’18, Marino et al, 77, McPherson et al, ’04) as elite players moved through larger ranges of motion faster than non-elite players.
- Budarick, A. R., Shell, J. R., Robbins, S. M., Wu, T., Renaud, P. J., & Pearsall, D. J. (2018). Ice hockey skating sprints: run to glide mechanics of high calibre male and female athletes. Sports Biomechanics, 1-17.
- Garrett, W. E., & Kirkendall, D. T. (2000). Exercise and sport science: Lippincott Williams & Wilkins.
- Lafontaine, D. (2007). Three-dimensional kinematics of the knee and ankle joints for three consecutive push-offs during ice hockey skating starts. Sports Biomechanics, 6(3), 391-406.
- Marino, G. W. (1977). Kinematics of ice skating at different velocities. Research Quarterly. American Alliance for Health, Physical Education and Recreation, 48(1), 93-97.
- McPherson, M. N., Wrigley, A., & Montelpare, W. J. (2004). The biomechanical characteristics of development-age hockey players: Determining the effects of body size on the assessment of skating technique. In Safety in ice hockey: fourth volume: ASTM International.
- Shell, J. R., Robbins, S. M., Dixon, P. C., Renaud, P. J., Turcotte, R. A., Wu, T., & Pearsall, D. J. (2017). Skating start propulsion: three-dimensional kinematic analysis of elite male and female ice hockey players. Sports Biomechanics, 16(3), 313-324.
- Stidwill, T., Pearsall, D., & Turcotte, R. (2010). Comparison of skating kinetics and kinematics on ice and on a synthetic surface. Sports Biomechanics, 9(1), 57-64.
- Stull, J. D., Philippon, M. J., & LaPrade, R. F. (2011). “At-risk” positioning and hip biomechanics of the Peewee ice hockey sprint start. The American journal of sports medicine, 39(1_suppl), 29-35.
- Upjohn, T., Turcotte, R., Pearsall, D. J., & Loh, J. (2008). Three-dimensional kinematics of the lower limbs during forward ice hockey skating. Sports Biomechanics, 7(2), 206-221.
- Wu, T., Pearsall, D. J., Russell, P. J., & Imanaka, Y. (2016). Kinematic comparisons between forward and backward skating in ice hockey.Paper presented at the ISBS-Conference Proceedings Archive.