## 4 Discussion
### Prevalence of Lower Back Complaints with Respect to Sex, Category and Discipline Preference  
The current study found relatively high rates of lower back complaints in adolescent competitive alpine skiers. Indeed, 50.0% and 80.3% of the participants displayed lower back complaints in the last 7 days and 12 months, respectively. These values are considerably higher than those was previously reported for other populations. For example, a 12 months lower back pain prevalence of between 49.8% and 65.0% was observed in previous studies in elite athletes of different sports [25; 26; 27]. A 7 days lower back pain prevalence between 19.4% and 25.3% was reported for endurance athletes [25]. Previous works found a 12 months lower back complaints prevalence ranging from 20.5% to 57.0% in non-athletic adolescents [25; 28; 29], while a 7 days lower back complaints prevalence of about 20.0% was reported for young non-athletes [25]. The higher prevalence of lower back complaints observed in the present study compared to other athletic (and non-athletic) adolescents suggests that competitive alpine skiers are especially prone for lower back complaints. Indeed, in the sport of alpine ski racing, repetitive and heavy mechanical loads, high ground reaction forces, and the exposure to low-frequency whole-body vibrations have \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Characteristic Pain Intensity** & **Disability Score** \\ \hline Years of sports participation & 0.28 ** & 0.15 * \\ \hline Number of competitions/season & 0.21 ** & \(-\)0.02 \\ \hline Number of skiing days/season & 0.27 ** & 0.12 \\ \hline Number of athletic preparation & & \\ days/season & 0.03 & \(-\)0.09 \\ \hline \hline \end{tabular} Level of significance based on Pearson correlation analysis: * \(p\) \(<\) 0.05, ** \(p\) \(<\) 0.01.  
\end{table} 
Table 3: Correlation between the Grading Chronic Pain Scale scores and questions on sports exposure. been shown to adversely affect the spinal structures while skiing [14; 16; 17]. Moreover, in young skiers, the immaturity of the musculoskeletal system may exacerbate the damage experienced by the spine during the practice of this sport [13]. Despite these plausible sports-related adverse loading patterns, only a few studies, however, have investigated the occurrence of lower back complaints in competitive alpine skiers. Moreover, due to focusing on a different age group and reporting other time prevalence measures or absolute injury rates, most of them are not directly comparable to the results of the current study [3; 4; 6; 8; 11]. The only study directly comparable to our investigation reported similar magnitudes of current low back pain (67.0%) in ski high school athletes aged 15-19 years [30]. Noteworthy, in our study, a higher 7 days lower back complaints prevalence was observed in females with respect to males (60.3% vs. 42.7%). These results are in agreement with previous works and, on the one hand, may be explained by a different pain threshold and symptom perception between males and females [31; 32]. On the other hand, this sex difference may also be explained by the different anatomical characteristics of the female body (e.g., greater spine flexibility), as well as the different pubertal growth and hormonal states [33; 34]. Furthermore, our study revealed that, during the 12 months prior to data collection, 28.2% of the participants were restricted in carrying out normal daily life activities, while 27.2% needed to see a physician. This latter percentage is similar to the magnitudes found in previous studies (range between 24.0 and 33.0%) including large cohorts of children and adolescents [35; 36]. Interestingly, we found different skiing disciplines to have different perceived impacts on lower back complaints. Indeed, 50.7% attributed their lower back complaints to SL, while 26.0% reported to have suffered them in connection with GS and 7.3% with SG. None of the participants attributed their lower back complaints to DH.