See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/40542873 Ski Sickness in Adolescents Skiers Article in Iranian Journal of Pediatrics · January 2009 Source: DOAJ CITATIONS READS 0 20 3 authors, including: Reza Alizadeh Vahid Ziaee 5 PUBLICATIONS 10 CITATIONS 171 PUBLICATIONS 946 CITATIONS AJA University of Medical Sciences SEE PROFILE Tehran University of Medical Sciences SEE PROFILE Some of the authors of this publication are also working on these related projects: Frequency of MEFV Gene In Parents of Children with Familial Mediterranean Fever View project All content following this page was uploaded by Vahid Ziaee on 05 December 2016. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. Short Communication Iran J Pediatr Dec 2009; Vol 19 (No 4), Pp:409-412 Ski Sickness in Adolescents Skiers Reza Alizadeh1,2, MD; Vahid Ziaee*1,3, MD; Ziba Aghsaei­Fard1, MD; Mehrab Hojat2, MD . Sports Medicine Research Center, Tehran University of Medical Sciences, Tehran, )R )ran . AJA University of Medical Sciences, Tehran, )R )ran . Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, )R )ran Received: Jan 22, 2008; Final Revision: May 20, 2009; Accepted: Jun 18, 2009 Abstract Objective: There is shortage of knowledge about medical problems in adolescent skiers. This study aimed to determine frequency of medical signs and symptoms during or after ski among adolescents skiers. Methods: This cross sectional study was performed in consecutive weekends in winter at Dizin ski resort in )ran. All adolescent skiers < years who had entered the resort during this time period were enrolled in the study. A questionnaire including demographics, duration of transport to the resort, wearing glasses and contact lenses for medical and non medical applications, duration and frequency of skiing and development of signs and symptoms of ski sickness during or after skiing was filled for each participant. )n addition, association of mentioned variables with medical problems was investigated. Findings: Of skiers, subjects . % were males. The mean age of the participants was . ± . years. Of them, skiers wore glasses or lens during skiing. Visual disorders including myopia, hyperopia and astigmatism were found in . % skiers. Our study showed that the frequency of main ski‐related signs and symptoms varies from to . %. There was significant association between occurrence of signs and symptoms and presence of visual disorder P= . . Conclusion: Our results showed that development of ski‐related signs and symptoms is relatively frequent. These signs and symptoms have association with minor ophthalmologic problems such as myopia or astigmatism. Iranian Journal of Pediatrics, Volume 19 (Number 4), December 2009, Pages: 409­412 Key Words: Ski sickness; Ski; Visual disorder; Vestibular disorder Introduction Ski is a popular sport all over the world. This popularity raises more attention to the medical aspects of this sport. )t has been shown that some skiers suffer from medical symptoms during or after ski especially downhill skiing. Turning motions of skis, the * Corresponding Author; Address: No 7, Sports Medicine Research Center, Al‐e‐Ahmad Freeway, Tehran, )R )ran E­mail: ziaee@tums.ac.ir © by Pediatrics Center of Excellence, Children’s Medical Center, Tehran University of Medical Sciences, All rights reserved. Ski Sickness; R Alizadeh, et al 410 lack of oxygen in higher altitudes and altitude illness including headache, vertigo and acute mountain sickness can result in some symptoms in ski athletes[ , , ]. Accordingly a [ ] as new term was defined by (uesler in ski sickness . (e described a sickness in skiers including dizziness with delusional rotatory or pendular sensations and imbalance accompanied by nausea and occasionally vomiting. The clinical and pathophysiologic features of ski sickness are markedly different from those of acute mountain sickness. )t is a special form of motion sickness which is produced by unusual and contradictory sensory information between the visual, vestibular and somato‐sensory systems[ ]. (owever, exact definition and diagnostic criteria of ski sickness have not yet been established. Moreover, at present there is shortage of knowledge about medical problems in skiers particularly in adolescent skiers. Thus, in this study we aimed to determine the frequency of non injury‐related medical problems in adolescents skiers. Subjects and Methods A cross sectional study was performed during consecutive weekends in winter at Dizin skiing resort. Dizin is the largest ski resort in the Middle East and is situated near Tehran, the capital of )ran. This resort is an international and standard resort in )ran established in . The highest and lowest points of the field are located respectively m and m above the sea. )n this period, all adolescent skiers aged < years including both recreational and professional skiers who entered the Dizin Ski resort were enrolled in the study. The study protocol was approved by the Ethics Committee of Tehran University of Medical Sciences and after explaining the study design and objective for the adolescents and their parents, we obtained their verbal consent. Sample size was calculated based on Ballester and (ausler study[ ] which showed the estimated incidence of % for vestibular symptoms in skiers. By considering α< . and power of %, the calculated sample size was . A questionnaire including demographics, duration of transport to the resort, wearing glasses and contact lenses for medical and non medical applications, duration and frequency of skiing and development of signs and symptoms during or after skiing was filled for each participant. The questionnaire was filled by trained physicians who took history and performed examination before and after skiing. The software statistical package for the social sciences SPSS, version . was used for statistical analysis. The relation between categorical variables sex, presence of visual disorder, and wearing glasses for medical and non medical applications and ski sickness was assessed by chi square. )ndependent samples t‐ test was used to analyze numerical variables age, duration and frequency of skiing and duration of transport to the ski resort . P values less than . were considered statistically significant. Table 1: Frequency of wearing glasses and contact lenses for medical and non‐medical applications in adolescents skiers Type of instrument Medical Contact lens for medical application Non­Medical contact lens Glasses for medical application Sport glasses Routine wearing Wearing during ski . % . % . % . % . % % . % Iran J Pediatr; Vol 19 (No 4); Dec 2009 411 Findings During this period, consecutive adolescent skiers entered the study. Among the subjects, there were . % males. The mean age of the cases was . ± . years. . % individuals wore glasses either for medical or non medical application during skiing Table . None of the participants had hearing assistive devices. Visual disorders were found in . % cases as follow; myopia n= , . %, hyperopia n= , . % and astigmatism n= , % . Upper respiratory tract infectious were found in . % of skiers, one of whom had taken antihistamine agents. Frequency of developed signs and symptoms in skiers is shown in Table . As the table shows, nystagmus was the most frequent sign, observed in . % skiers. Comparison of descriptive variables for symptomatic and non‐symptomatic skiers is demonstrated in table . There was significant association between presence of visual disorders and development of medical problems. Table 2: Frequency of developed signs and symptoms in adolescents skiers Signs and symptoms Frequency (%) Nystagmus True vertigo Headache Imbalance Tinnitus Dizziness Nausea Visual disturbance Vomiting . . . . . . . Discussion This study aimed to evaluate signs and symptoms in adolescent skiers during skiing. Ski sickness is a new term which has been introduced in recent years. )t occurs in susceptible individuals especially those with myopia or astigmatism when visual, vestibular and peripheral sensory information is conflicting. Symptoms are dizziness with rotatory or pendular sensations, nausea and vomiting. Development of these signs and symptoms are related to the inner ear organs which are used to maintain postural balance during skiing[ ]. Previous studies demonstrated that development of these signs and symptoms occurs relatively frequently and is mostly associated with minor ophthalmologic disorders such as myopia or astigmatism and altered somato‐sensory input due to wearing ski boots and skis. Our study showed that the frequency of main ski‐related signs and symptoms varies from to . %. This ratio in all skiers adults and adolescents was . %‐ . % in our prevous study[ ]. Our results showed that vomiting and visual disturbances are rare while nystagmus is a common sign. Similar to previous study by (ausler[ ], our results revealed that presence of visual disorders is associated with development of ski sickness. )t seems that nystagmus and vertigo are the main criteria for ski sickness, while headache is not a main criterion, because this symptom is also common in mountain sickness. (owever, there are difficulties in differentiating these sicknesses, because they have similar signs, symptoms and etiology. Other variables such as age, sex, duration of transport to the resort and wearing glasses for medical application were not related to ski sickness. Skiing and sickness had the same frequency. Regarding the effect of wearing glasses for medical application, our results are in contrast to previous study which showed significant association between wearing glasses for medical application and occurrence of ski sickness in adults [ ]. (owever, other findings in our study, particularly frequency of developed signs and symptoms, are similar to what have been reported in adult skiers. Our study shows the importance of ophthalmologic examination in adolescents who have the sickness. Also it seems that frequency of skiing should be considered as an effective factor especially in adolescents who have ski sickness. Ski Sickness; R Alizadeh, et al 412 Table 3: Comparison of variables in symptomatic and non‐symptomatic adolescents skiers Variables Symptomatic skiers non­symptomatic skiers P­value . ± . . ± . Age(mean±SD)/years Duration of skiing/hours (mean±SD) Frequency of skiing (meant±SD) Transport duration (mean±SD)/hours Sex (male) Routine wearing glasses for medical application (positive) Wearing glasses for medical application during ski (positive) Visual disorders (positive) The limitation of this study was, like in previous studies, not having the possibility to differentiate some probable overlaps of signs and symptoms of ski sickness and acute mountain sickness. Conclusion )t seems that ski sickness is independent from motion sickness in spite of their similarity. Nystagmus and vertigo are the main criteria for ski sickness. This study revealed some factors associated with ski sickness however; more studies are required to develop diagnostic criteria and other risk factors of ski sickness in both adults and adolescents. Acknowledgment This study was approved and funded by Sports Medicine Research Center and Vice Chancellor for Research of Tehran University of Medical Sciences grant No. . Authors would like . ± . . . ± . . . ± . . % . % . % . % ± . . ± . . ± . % . % . . . % . % . . . . to thank all skiers who volunteered for this study. References . (ausler R. Ski sickness. Acta Oto‐Laryngo‐ logica. ; : ‐ . . Noe F, Paillard T. )s postural control affected by expertise in alpine skiing? Br J Sports Med. ; : ‐ . . Frank BC. Risk of injuries, symptoms of excessive strain and preventive possibilities in cross country skiing. A comparison between classical technique and skating technique. Sportverletzung Sportschaden. ; : ‐ . . Ballester M, (ausler R. Ski sickness. Sci Sports. ; : ‐ . . Smart LJ, Stoffiregen TA, Bardy BG. Visually induced motion sickness predicted by postural instability. (uman Factors. ; : ‐ . . Ziaee V, Alizadeh R, Fallah J, et al. Frequency of medical symptoms in )ranian skiers. Journal of Medical Council of )slamic Republic of )ran. ; : ‐ . Persian