Abstract
Alpine skiing, both recreational and competitive, is associated with high rates of injury. Numerous studies have shown that occupational exposure to whole-body vibrations is strongly related to lower back pain and some suggest that, in particular, vibrations of lower frequencies could lead to overuse injuries of the back in connection with alpine ski racing. However, it is not yet known which forms of skiing involve stronger vibrations and whether these exceed safety thresholds set by existing standards and directives. Therefore, this study was designed to examine whole-body vibrations connected with different types of skiing and the associated potential risk of developing low back pain. Eight highly skilled ski instructors, all former competitive ski racers and equipped with five accelerometers and a Global Satellite Navigation System to measure vibrations and speed, respectively, performed six different forms of skiing: straight running, plowing, snow-plow swinging, basic swinging, short swinging, and carved turns. To estimate exposure to periodic, random and transient vibrations the power spectrum density (PSD) and standard ISO 2631-1:1997 parameters [i.e., the weighted root-mean-square acceleration (RMS), crest factor, maximum transient vibration value and the fourth-power vibration dose value (VDV)] were calculated. Ground reaction forces were estimated from data provided by accelerometers attached to the pelvis. The major novel findings were that all of the forms of skiing tested produced whole-body vibrations, with highest PSD values of 1.5–8 Hz. Intensified PSD between 8.5 and 35 Hz was observed only when skidding was involved. The RMS values for 10 min of short swinging or carved turns, as well as all 10-min equivalent VDV values exceeded the limits set by European Directive 2002/44/EC for health and safety. Thus, whole-body vibrations, particularly in connection with high ground reaction forces, contribute to a high risk for low back pain among active alpine skiers.
Highlights
Physical activity is beneficial to human health, for example by reducing the risk of chronic disease, among the most common injuries in modern Western societies are those related to sports (Parkkari et al, 2001)
At the same time, plowing, snowplow swinging, basic swinging and short swinging exhibited two regions of intensified power spectrum densities (PSD) (Figure 2B), the first between ∼1.5 and ∼8 Hz and the second between ∼8.5 and ∼35 Hz, above which the PSD values declined. These attenuations of the PSD curves continued for all six types of skiing until ∼70 Hz, above which the values remained steady until 200 Hz, followed by another attenuation (∼200–500 Hz), remaining more or less constant until 2.5 kHz, where the power densities were 2–3 orders of magnitude lower than the maximal values
Overall means ± standard deviations and the results of the ANOVA and paired sample t-test are presented. 10 min, 10-min equivalent; 8 h, 8-h equivalent; §, only pairs for which p ≥ 0.05 are shown; SR/SPS, straight running vs. snow-plow swinging; #, one skier was excluded from the maximum transient vibration value (MTVV) analysis to obtain normal distribution of these data
Summary
Physical activity is beneficial to human health, for example by reducing the risk of chronic disease, among the most common injuries in modern Western societies are those related to sports (Parkkari et al, 2001). It has been proposed that such overuse injuries to the lower back might be reduced by controlling and/or reducing frontal and lateral bending, as well as torsion of the trunk and peak load while skiing (Spörri et al, 2015, 2016). These studies found no differences in low-back kinematics when skis with different side-cut radii were utilized. Little is presently known about the nature and frequency of overuse injuries in alpine skiing, including when and why they occur (Supej et al, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
