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1.
No Shinkei Geka ; 48(6): 521-526, 2020 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-32572004

RESUMO

Second impact syndrome occurrs when a patient who has sustained an initial head injury, most often a concussion, sustains a second head injury before the symptoms associated with the first have fully resolved, leading to rapid brain swelling and herniation. However, the underlying pathophysiology remains unclear. We report two cases in which acute subdural hematoma with rapid malignant brain swelling developed after repeated head traumas while snowboarding. One patient did not undergo craniotomy and died 21h after symptom onset. The other underwent urgent decompressive craniotomy and experienced prolonged disturbance of consciousness. Axial susceptibility-weighted magnetic resonance imaging performed 1 month after surgery in the second patient revealed multiple microbleeds in the subcortical white matter and parasagittal white matter in the bilateral hemispheres. These findings indicate that axonal injuries from angular acceleration may contribute to the rapid malignant brain swelling and poor outcomes.


Assuntos
Concussão Encefálica , Lesões Encefálicas Traumáticas , Traumatismos Craniocerebrais , Hematoma Subdural Agudo , Esqui , Humanos
2.
Ying Yong Sheng Tai Xue Bao ; 31(4): 1259-1266, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32530201

RESUMO

To analyze the climatic characteristics of snow resources and quantitatively evaluate the climatic suitability of skiing, we proposed the concept of theoretical snow period from the perspective of climate based on the synoptic principle. We set threshold values of different suitability degrees of three indices closely related to skiing, including air temperature, wind speed, and precipitation. The conversion function of each index was designed after normalization. Based on grey relational theory and Euclidean distance method, we established evaluation model of ski sports climate suitability index, with Changbai Mountain Ski Resort as an example. The results showed that snow resource in Changbai Mountain area was rich. From 1981 to 2018, the average snowfall during the theoretical snow period was 64.6 mm. Under the background of climate change, the average number of snow days and snowfall decreased slightly over the years, with the starting time of snow season being delayed and the ending time being advanced. The number of snow days in the early winter (from the starting time of snow season to the end of December) was significantly less than that in the later winter (from the next January to the end of snow season). Climate in Changbai Mountain was highly suitable for skiing during the snow period. The most suitable and relatively suitable days with respect to air temperature, wind speed and precipitation accounted for 91.9%, 91.8%, and 94.6% of the total, respectively. The cumulative number of days for ski comprehensive weather suita-bility accounted for 99.7%, indicating that most days were suitable for skiing. The concept of theoretical snow period in this study had made up for the problems caused by the lack of meteorological observation data of the first and last snow event on the study of snow resources. The climate suitabi-lity evaluation model of skiing could help make management decision for the development and operation of ski resorts and scientific support for skiing enthusiasts.


Assuntos
Esqui , Neve , Mudança Climática , Estações do Ano , Tempo (Meteorologia)
3.
PLoS One ; 15(4): e0231384, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32352980

RESUMO

While research on the effects of 'birth month' is usually referred to as relative age effects, the study of the effects of 'birth year' is described as the constituent year effect (CYE). In the present study we examined the impact of the CYE on participation in the Junior World Championship in alpine skiing. Based on previous research, we expected to find increasing numbers of participants the older the age-group, and that the CYE would be stronger in the speed events compared to the technical ones. The sample in the present study consisted of 1188 male skiers and 859 female skiers within the age range of 17 to 21 years at the time of competition. The results show that the number of male participants increased with increasing age, which can be described as a CYE. For female skiers, a CYE was found, but it dissipated two years earlier than for male skiers. The CYE varied with event and was more pronounced the higher the speed of the event. The findings thus suggest that a constituent year effect exists among skiers participating in the FIS Junior World Ski Championship in the alpine skiing championships, and that the effect varies with gender and event, rather unrelated to age. Thus, it seems that the effect may not be a relative age effect, but instead a relative development effect.


Assuntos
Desempenho Atlético , Esqui , Adolescente , Fatores Etários , Feminino , Humanos , Masculino , Adulto Jovem
4.
J Sports Sci Med ; 19(1): 112-120, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32132834

RESUMO

Recent research has shown multiple motives for high-risk sport participation derived from research on adult participants. The aim of this study was to provide insights into motives and risk-related aspects in adolescent high-risk sport participants and to compare those findings with adults performing the same activity. Semi-structured interviews were conducted with 24 adolescent (14-20 years) freeriders (skiers/snowboarders who ski outside the protected areas of a ski resort) and 24 adult freeriders (26-41 years). A content analyses was done using MAXQDA software. Both cohorts reported the motives Challenge (adolescents: 92%, adults: 88%), Freedom/Pleasure (adolescents: 88%, adults: 75%), Friends (adolescents: 88%, adults: 79%) and Balance (adolescents: 63%, adults: 63%). However, the description of friends differed between adults and adolescents. Whereas adolescents mostly referred to a community and shared interests, adults described the importance of trust and the development of deep friendships through the activity more often. Nature was a major motive in adults (83%) but not in adolescents (29%). Most of the adults have already experienced a major accident or close call (n = 19; 79%), contrary to adolescents (n = 7; 29%). Adolescents learned about the risks in freeriding primarily through their families (n = 10) and the ski club (n = 9). Some adults reported to have realized the risks involved in freeriding after starting with the activity due to experienced negative outcomes. Both cohorts were largely motivated by the same motives. As the new generation of freeriders seems to receive more instructions about risk reduction, it might be interesting to see if this educational approach results into less accidents or close calls in this group.


Assuntos
Motivação/fisiologia , Assunção de Riscos , Esqui/psicologia , Adolescente , Adulto , Fatores Etários , Conscientização/fisiologia , Feminino , Amigos/psicologia , Humanos , Entrevistas como Assunto , Masculino , Prazer/fisiologia , Pesquisa Qualitativa , Comportamento de Redução do Risco , Esqui/lesões , Adulto Jovem
5.
J Sports Sci ; 38(8): 863-872, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32138604

RESUMO

We aimed to evaluate the changes in double poling (DP) kinematics due to a long-distance cross-country skiing race in athletes with different performance levels. A total of 100 cross-country skiers, belonging to 10 different performance groups, were filmed on flat terrain 7 and 55 km after the start line, during a 58-km classical race. Cycle velocity, frequency and length decreased from the best to the lower-ranked group, while duty cycle increased (all P <.001). Between track sections, cycle velocity and length decreased, duty cycles increased (all P <.001) while frequency was unaltered (P =.782). Group*section interactions resulted for cycle velocity (P =.005). Considering all the participants together, % change in cycle velocity between sections correlated with % change in length and duty cycle (all P <.001). Thus i) skiers in better groups showed longer and more frequent cycles as well as shorter duty cycles than skiers in slower groups; ii) throughout the race all the groups maintained the same cycle frequency while decreasing cycle velocity and length; iii) better groups showed a lower reduction in cycle velocity. Individually, a low reduction in cycle velocity during the race related to the capacity to maintain long cycles and short duty cycles.


Assuntos
Destreza Motora/fisiologia , Resistência Física/fisiologia , Esqui/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Fadiga Muscular/fisiologia , Estudos de Tempo e Movimento
6.
Isotopes Environ Health Stud ; 56(1): 36-50, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32067470

RESUMO

A scarce natural snow cover forces an increasing use of artificial snow on ski slopes and returns a small amount of snowmelt water available to plants outside the pistes at the beginning of the growing season. We tested if the use of artificial snow on the ski slopes and the decreased natural snow cover outside the ski slopes lead to changes in the leaf ecophysiology of dominant species in a ski area located in Northern Italy. Using carbon (13C/12C) and oxygen (18O/16O) stable isotope ratios in plant leaves, we estimated the intrinsic water use efficiency (iWUE) and we speculated about changes in photosynthesis and stomatal conductance. Furthermore, carbon and nitrogen concentration, pigments and dry matter content, and the specific area of leaves were measured. We found a higher iWUE of the plants on the ski slopes than outside, probably because the plants on the ski piste are exposed to a condition close to waterlogging that can lead them to regulate their stomata differently than the plants outside the pistes. This behaviour was observed particularly in Ranunculus acris and in Tussilago farfara, for these species the water surplus on the piste may have affected the plants' gas exchanges.


Assuntos
Monitoramento Ambiental/métodos , Água Doce/análise , Pradaria , Folhas de Planta/química , Esqui/normas , Neve/química , Altitude , Isótopos de Carbono/análise , Itália , Isótopos de Oxigênio/análise , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Estações do Ano
7.
Artigo em Inglês | MEDLINE | ID: mdl-31906403

RESUMO

The objectives of the present study were to assess general perceptions of safety in snow parks (SPs), general knowledge of rules existence, and both active and passive awareness of the International Ski Federation (FIS) rules contained in its Code of Conduct for SPs in order to define target groups for injury prevention-specific education interventions. Data were drawn from 436 freestylers randomly interviewed. The study was conducted during the 2018-2019 winter season in the SP of a major winter resort located in the Spanish Pyrenees. A questionnaire assessing personal data (gender, age, gear used, self-reported skill, and frequency of use), general perceptions on safety, general request for rules, and awareness of existing rules in SPs was developed. Chi-square goodness-of-fit tests were used to compare characteristics between groups. It was revealed, for accident prevention purposes, a concerning general lack of knowledge of existing rules in SPs (63% of participants ignored them). Risk-inducing situations that could result in severe injuries, such as familiarity with the right progression in choosing features and/or stunts or with safety equipment, were largely assessed incorrectly (94% and 70% of participants, respectively). Appropriate intuitive behavior increases with experience: youths and beginners are less able to implement FIS rules than more experienced freestylers.


Assuntos
Prevenção de Acidentes , Atletas , Parques Recreativos , Neve , Prevenção de Acidentes/estatística & dados numéricos , Adolescente , Adulto , Atletas/psicologia , Atletas/estatística & dados numéricos , Conscientização , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Parques Recreativos/estatística & dados numéricos , Esqui , Inquéritos e Questionários , Adulto Jovem
8.
Artigo em Inglês | MEDLINE | ID: mdl-31906438

RESUMO

The objective of the present study is to assess snowboarders' general perceptions of safety and knowledge of existing rules and both active and passive knowledge of the International Ski Federation (FIS) regulations in order to contribute to defining target groups for specific educational interventions in the field of injury prevention. Data were drawn from random interviews conducted with 918 snowboarders during the 2017-2018 winter season at five ski resorts located in the Spanish Pyrenees. To collect the data, a questionnaire assessing personal characteristics (gender, age, origin, and self-reported skill), general perception of safety, general request for rules, and knowledge of existing rules was used. Pearson's Chi-squared tests were performed to compare characteristics between groups. The study revealed, for accident prevention purposes, a concerning lack of general knowledge of existing rules. Risk-inducing situations that could result in severe injuries were largely assessed incorrectly. The appropriate intuitive behavior increases with age and experience: youths and beginners are less able to implement the FIS rules than older and more experienced snowboarders. Stakeholders, such as parents, ski resorts, clubs or schools, should direct educational efforts at high-risk groups. Further research is needed to determine the causal relation between snowboard-related injuries and disregard of FIS rules.


Assuntos
Prevenção de Acidentes , Traumatismos em Atletas/prevenção & controle , Esqui , Controle Social Formal , Adolescente , Adulto , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Autorrelato , Esqui/lesões , Esqui/psicologia , Inquéritos e Questionários
9.
Int J Sports Physiol Perform ; 15(5): 663-670, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32000138

RESUMO

PURPOSE: To investigate the factors associated with underperformance and the subsequent changes in training characteristics and supportive actions when returning to the world's best cross-country skier. METHODS: The participant is the most decorated winter Olympian, with 8 Olympic gold medals, 18 World Championship titles, and 114 World Cup victories. Training data were categorized by training form (endurance, strength, and speed); intensity (low, moderate, and high); and mode (running, cycling, and skiing/roller skiing). In addition, test data were retrospectively analyzed, and interviews were performed with the participant and her support team. RESULTS: After the competitive season, the participant had 8 weeks without systematic training and an evaluation process aiming to detect the factors contributing to underperformance. Here physiological, technical, and psychological challenges were detected. As a consequence, the participant included less high-intensity training (1.2 vs 2.1 sessions/wk, P = .011); more moderate-intensity training (0.9 vs 0.4 sessions/wk, P = .016); and more low-intensity training (6.9 vs 5.9 sessions/wk, P = .036) during the general preparation phase but with similar total endurance training load as previous season. In addition, more strength training (1.6 vs 1.1 h/wk, P = .036) and new ski-specific strength exercises were included. Finally, the athlete's autonomy when planning and adjusting training was increased, nontraining stressors were reduced, more frequent testing was included, systematic mental training was initiated, her nutritional strategy was adjusted, and her asthma treatment was optimized. CONCLUSIONS: Overall, the current case study could be used as a framework for the holistic approach to treating an overtraining condition and for generation of new hypothesis in this exiting area.


Assuntos
Comportamento Competitivo/fisiologia , Condicionamento Físico Humano/métodos , Resistência Física/fisiologia , Esqui/fisiologia , Esqui/psicologia , Transtornos Traumáticos Cumulativos/prevenção & controle , Dieta , Feminino , Humanos , Fadiga Mental/fisiopatologia , Fadiga Muscular/fisiologia , Autonomia Pessoal , Condicionamento Físico Humano/fisiologia , Treinamento de Resistência , Estresse Psicológico/prevenção & controle , Fatores de Tempo
10.
Int J Med Inform ; 136: 103977, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31978809

RESUMO

BACKGROUND AND OBJECTIVE: This study proposes an approach to evaluation and measuring of presence for man-machine interaction in the virtual reality based on electroencephalographic data. MATERIALS AND METHODS: It analyzes stable electroencephalographic patterns that allow us to trace a connection between a brain activity and purposeful actions of an individual in various environments. The subjects of the study were experienced downhill skiers equipped with electroencephalographs, who performed real-life skiing on a downhill course, after which they were offered a virtual simulation of downhill skiing using an HTCVive headset and a programmed 2D or desktop simulator. RESULTS: The results of measurement showed neuropatterns similar in the cases of virtual reality simulation and physical downhill skiing (in part of changes in space and power parameters of electroencephalograms in the different frequency ranges) and different from a 2D simulator. This observation enables us to make an assumption of realism of a virtual reality simulator in the context of reproduction of the subjects' similar cognitive and semantic connections and motor programs. DISCUSSION: Further research work will focus on evaluation of efficiency in performing psychophysiological tests (time response to a mobile object) in the virtual reality and 2D desktop application.


Assuntos
Encéfalo/fisiologia , Simulação por Computador , Eletroencefalografia/métodos , Vias Neurais , Esqui/fisiologia , Interface Usuário-Computador , Realidade Virtual , Cognição/fisiologia , Medo/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Semântica
11.
Int J Sports Med ; 41(3): 196-202, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31935775

RESUMO

This study aimed to assess prevalence and incidence of chronic exertional compartmental syndrome as well as functional outcomes after surgery in elite Nordic skiers. An exhaustive list of 294 elite Nordic skiers from the French national teams between 1994 and 2014 was analyzed through their individual medical files in order to identify cases of chronic exertional compartmental syndrome. Eighteen athletes had confirmed diagnosis and performed a structured interview to identify factors associated with chronic exertional compartmental syndrome and surgery outcomes. The prevalence was 6.1% and the incidence 13 per 1000 skier-years. Biathletes had a higher prevalence than cross-country skiers (OR=0.40, p=0.08). Free-technique skiing and roller-skiing were the main conditions inducing symptoms. All injured athletes had bilateral surgery and 94% of them reported no more or sporadic leg pain after. Almost 90% resumed competition at the same or higher level than prior surgery. Compare to previous studies, the incidence rate of chronic exertional compartmental syndrome is higher in French elite Nordic skiers. The higher prevalence in biathletes and the trigger during free-technique skiing suggest a contribution of this technique to this disease. This study also confirmed that surgery was an efficient therapeutic solution without compromising athletes' career.


Assuntos
Síndromes Compartimentais/epidemiologia , Traumatismos da Perna/epidemiologia , Resistência Física/fisiologia , Esqui/lesões , Síndromes Compartimentais/cirurgia , França/epidemiologia , Humanos , Incidência , Traumatismos da Perna/cirurgia , Prevalência , Estudos Retrospectivos , Resultado do Tratamento
12.
Artigo em Inglês | MEDLINE | ID: mdl-31948103

RESUMO

Alpine ski racing is a sport with a high risk of injuries. In order to contribute to the longitudinal career development of young athletes, prevention measures should be elaborated. Therefore, the aim of the present study was to investigate prospectively the role of biological maturity status, and changes in anthropometric characteristics and physical fitness parameters over one season in elite youth ski racers younger than 15 years. Eighty-nine elite youth ski racers (39 females, 50 males), aged 10-14 years (mean age: 12.1 ± 1.3), were investigated. Anthropometric characteristics and physical fitness parameters were assessed prior and after the winter season; traumatic and overuse injuries were recorded over the 32 weeks. Binary logistic regression analyses (R² = 0.202-0.188) revealed that the biological maturity (Wald = 4.818; p = 0.028), and changes over the season in the jump agility test (Wald = 4.692; p = 0.03), in body height (Wald = 6.229; p = 0.013), and in leg length (Wald = 4.321; p = 0.038) represented significant injury risk factors. Athletes who could improve their jump agility performance more, had smaller changes in the anthropometric characteristics and who were closer to their peak height velocity were at a lower injury risk. In the context of injury prevention, regular neuromuscular training should be incorporated, and phases of rapid growth have to be considered.


Assuntos
Desenvolvimento do Adolescente , Atletas/estatística & dados numéricos , Traumatismos em Atletas/epidemiologia , Aptidão Física , Esqui/lesões , Adolescente , Fatores Etários , Antropometria , Traumatismos em Atletas/etiologia , Áustria/epidemiologia , Estatura , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco , Estações do Ano , Esqui/fisiologia
13.
J Sports Med Phys Fitness ; 60(1): 119-124, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31640310

RESUMO

BACKGROUND: Alpine sports are associated with risk of serious injuries. To gain insight into factors that may help reduce injury severity, accident characteristics and injury patterns were analyzed in a cohort of injured skiers and snowboarders. METHODS: All patients with Alpine sports-related injuries, reporting the injury to a leading medical assistance organization in the Netherlands in the period of 2013-2016, were contacted. Medical data were collected from the patients' files. Only ski and snowboard incidents were included. Injuries were classified according to the Abbreviated Injury Scale (AIS) and Injury Severity Scale (ISS). Data on the accident conditions, i.e. risk factors, were collected using retrospective patient-reported questionnaires. Risk factors for injuries with ISS≥9 were analysed by multivariate modelling. RESULTS: Of the 1588 included patients, 421 patients filled out the questionnaire. Skiers (N.=1370) had more knee injuries (20.4% vs. 7.4%, P<0.001), femur fractures (5.3% vs. 0.5%, P=0.002) and lower leg fractures (27.5% vs. 11.5%, P<0.001) compared to snowboarders (N.=218). Skiers were also more seriously injured (ISS>9) (P=0.01). Injured snowboarders sustained more brain concussions (8.8% vs. 15.7%, P=0.003) and lower arm fractures (5.4% vs. 16.1%, P<0.001). Only 'a higher skills level' was borderline significant for predicting serious injury (OR: 4.0 95% CI: 0.86-18.50; P=0.08). No additional risk factors were identified. CONCLUSIONS: Injury patterns after skiing and snowboarding accidents differ, injury severity differed not. Preventive measures should therefore aim to protect specific body parts depending on the type of Alpine sport. Experienced skiers and snowboarders may be more at risk for serious injuries.


Assuntos
Acidentes/estatística & dados numéricos , Esqui/lesões , Adolescente , Adulto , Concussão Encefálica/epidemiologia , Bases de Dados Factuais , Feminino , Fraturas Ósseas/epidemiologia , Humanos , Escala de Gravidade do Ferimento , Traumatismos do Joelho/epidemiologia , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
14.
Sports Biomech ; 19(2): 157-167, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29781789

RESUMO

External supports that reduce ankle joint mobility such as ski-boots can impair postural control of healthy participants. Although this disruptive effect has been attributed to the rigidity of the external supports, the results remained controversial and no study has been conducted in order to evaluate the influence of ski-boots rigidity. Hence, the question about the influence of ankle support rigidity on postural control remains open. This study was therefore undertaken in order to investigate the effect of ski-boots rigidity on postural control. Ten healthy active participants were recruited. The wearing of soft and rigid ski-boots was compared to barefoot while standing on a seesaw generating mediolateral and anteroposterior instability. Centre of pressure displacements were sampled with a force platform. The surface electromyographic activity of the main muscles from the leg, thigh and trunk was recorded. A motion analysis system was also used to calculate the ankle, knee and hip angles. The results did not reveal any negative influence of ski-boot rigidity on postural control but rather suggest a less active postural control with the rigid ski-boots which offered a higher mechanical contribution.


Assuntos
Equilíbrio Postural/fisiologia , Sapatos , Esqui/fisiologia , Equipamentos Esportivos , Adolescente , Tornozelo/fisiologia , Fenômenos Biomecânicos , Eletromiografia , Desenho de Equipamento , Feminino , Quadril/fisiologia , Humanos , Joelho/fisiologia , Masculino , Movimento/fisiologia , Músculo Esquelético/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
15.
Internist (Berl) ; 61(1): 91-95, 2020 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-31673730

RESUMO

This article reports the case of a 43-year-old woman who presented to the emergency room with headache and paresthesia after a fall on the head while skiing. She had clinical signs of volume depletion and blood test showed severe hyponatremia. Cerebral imaging was unremarkable. The diagnosis of cerebral salt-wasting syndrome (CSWS) was made, which is defined by the presence of extracellular volume depletion due to a tubular defect in renal sodium transport in patients with normal adrenal and thyroid function. The disease is mostly secondary to a neurological disease or head trauma. The patient rapidly improved after volume therapy and treatment with mineralocorticoids. The differentiation of CSWS from the syndrome of inappropriate antidiuretic hormone (SIADH) secretion can be challenging but the distinction is important because treatment options are very different.


Assuntos
Traumatismos Craniocerebrais/complicações , Hiponatremia/etiologia , Síndrome de Secreção Inadequada de HAD/diagnóstico , Esqui/lesões , Acidentes , Adulto , Feminino , Humanos
16.
Med Sci Sports Exerc ; 52(1): 233-243, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31403609

RESUMO

PURPOSE: This study aimed to compare biceps femoris long head (BFlh) fascicle length (Lf) obtained with different ultrasound-based approaches: 1) single ultrasound images and linear Lf extrapolation, 2) single ultrasound images and one of two different trigonometric equations (termed equations A and B), and 3) extended field of view (EFOV) ultrasound images. METHODS: Thirty-seven elite alpine skiers (21.7 ± 2.8 yr) without a previous history of hamstring strain injury were tested. Single ultrasound images were collected with a 5-cm linear transducer from BFlh at 50% femur length and were compared with whole muscle scans acquired by EFOV ultrasound. RESULTS: The intrasession reliability (intraclass correlation coefficient [ICC3,k]) of Lf measurements was very high for both single ultrasound images (i.e., Lf estimated by linear extrapolation; ICC3,k = 0.96-0.99, SEM = 0.18 cm) and EFOV scans (ICC3,k = 0.91-0.98, SEM = 0.19 cm). Although extrapolation methods showed cases of Lf overestimation and underestimation when compared with EFOV scans, mean Lf measured from EFOV scans (8.07 ± 1.36 cm) was significantly shorter than Lf estimated by trigonometric equations A (9.98 ± 2.12 cm, P < 0.01) and B (8.57 ± 1.59 cm, P = 0.03), but not significantly different from Lf estimated with manual linear extrapolation (8.40 ± 1.68 cm, P = 0.13). Bland-Altman analyses revealed mean differences in Lf obtained from EFOV scans and those estimated from equation A, equation B, and manual linear extrapolation of 1.91 ± 2.1, 0.50 ± 1.0, and 0.33 ± 1.0 cm, respectively. CONCLUSIONS: The typical extrapolation methods used for estimating Lf from single ultrasound images are reliable within the same session, but not accurate for estimating BFlh Lf at rest with a 5-cm field of view. We recommend that EFOV scans are implemented to accurately determine intervention-related Lf changes in BFlh.


Assuntos
Músculos Isquiossurais/anatomia & histologia , Músculos Isquiossurais/diagnóstico por imagem , Feminino , Músculos Isquiossurais/lesões , Humanos , Masculino , Reprodutibilidade dos Testes , Fatores de Risco , Esqui/lesões , Esqui/fisiologia , Ultrassonografia/métodos , Adulto Jovem
17.
Br J Sports Med ; 54(1): 33-37, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31399428

RESUMO

OBJECTIVES: The risk of graft revision following ACL reconstruction may depend on the sport type the individuals are engaged in. The purpose of this study was to report the ACL graft revision rate in alpine skiers, football and handball players. MATERIALS AND METHODS: Primary ACL reconstructions and graft revision data from 2004 to December 2016 were obtained from the Norwegian Cruciate Ligament Registry. The graft survival rates were calculated for individuals in each of the three sport types, for bone patellar tendon bone (BPTB) and hamstring tendons (HT) grafts separately, and related to age at primary operation and sex. RESULTS: A total of 711 grafts in 14 201 primary ACL reconstructions were revised (5.0%) after median 6 years, 3.8% in alpine skiers, 5.0% in soccer and 6.1% in handball players (p<0.001). Adjusted Cox regression showed similar ACL graft survival rates in the three groups. The HR for graft revision was 5 times higher for individuals aged ≤18 years than for those aged ≥35 years (p<0.001). The corresponding HR for graft type was 1.8 times higher for HT than for BPTB grafts (p<0.001), but 2.8 times higher for individuals aged ≤18 years (p<0.001). The 12 years survival of BPTB grafts was 96% compared with 93% for HT grafts (p <0.001). CONCLUSION: The revision rate for ACL grafts was similar among alpine skiers, football and handball players, and the results support the use of BPTB grafts in young athletes with closed growth zones in the knee. STUDY DESIGN: Cohort study; level of evidence, 2.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Enxerto Osso-Tendão Patelar-Osso/métodos , Tendões dos Músculos Isquiotibiais/transplante , Esportes com Raquete/lesões , Reoperação , Esqui/lesões , Futebol/lesões , Adolescente , Adulto , Fatores Etários , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Masculino , Noruega , Sistema de Registros , Estudos Retrospectivos , Fatores Sexuais , Transplante Autólogo , Adulto Jovem
18.
Br J Sports Med ; 54(1): 44-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31527043

RESUMO

OBJECTIVES: To describe the incidence, type, aetiology and severity of injuries sustained by the International Ski Federation World Cup level female ski jumpers during the 2017-18 season. DESIGN: Prospective cohort study. METHODS: Sixty-seven female ski jump athletes from 16 countries were followed throughout the 17-week winter season. Preseason baseline demographic data and injury history were recorded via questionnaire. Prospective biweekly reports and retrospective end-of-season interviews provided data on all injuries requiring medical attention. RESULTS: Seventeen injuries were recorded, corresponding to an incidence of 25.4 injuries/100 athletes/season. The incidence of time-loss and severe injuries were found to be 17.9 and 4.5, respectively. The knee was the most common site of injury (4/17; 23.5%). Fourteen injuries occurred on the ski jump hill and crash-landing was the most common mechanism of injury (10/14; 71%). Eighty-five per cent of all moderate and severe injuries occurred in snow or windy conditions. Length of jumps resulting in injury averaged 83.7% (95% CI 72.9% to 94.4%) of hill size. Moderate injuries causing 8-28 days absence from training activities were most common (7/17; 41%) and there were three severe injuries necessitating >4 weeks absence. CONCLUSION: Injuries among elite female ski jumpers are common and the majority are acute, resulting in time loss from training and competition. The knee was the most common site of injury and poor weather conditions may be a risk factor. Future studies are needed to identify risk factors for injury and to guide injury prevention initiatives.


Assuntos
Traumatismos em Atletas/epidemiologia , Esqui/lesões , Aniversários e Eventos Especiais , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/prevenção & controle , Comportamento Competitivo/fisiologia , Transtornos Traumáticos Cumulativos/epidemiologia , Transtornos Traumáticos Cumulativos/prevenção & controle , Feminino , Humanos , Incidência , Traumatismos do Joelho/epidemiologia , Traumatismos do Joelho/etiologia , Traumatismos do Joelho/prevenção & controle , Condicionamento Físico Humano , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Índices de Gravidade do Trauma , Tempo (Meteorologia)
19.
J Sports Sci Med ; 18(4): 798-804, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31827365

RESUMO

In recent years, there is an increasing importance of double poling (DP) performance regarding the outcome in classic cross-country skiing (XCS) races. So far, different approaches were used to predict DP performance but there is a lack of knowledge how general strength parameters are related to DP performance parameters gathered from in field-test situations. Therefore, the aim of this study was to determine the relationship between general strength measurements of different upper-body segments and pole force measurements during a DP sprint exercise. In addition, multiple linear regressions were calculated to determine the predictive power of theses variables regarding DP sprint performance, represented as maximum velocity. Thirteen none-elite cross-country skiers performed two 60 m DP sprints at maximal speed on a tartan track using roller skis. In addition, maximum isometric and concentric strength tests were performed on a motor-driven dynamometer with four major upper-body segments (trunk flexion / extension, shoulder / elbow extension). Especially the mean pole force and the strength test parameters correlated significantly (r ≥ 0.615) in all except one comparison. However, regression analyses revealed that neither pole force parameters (R² = 0.495) nor isometric (R² = 0.456) or dynamic (R² = 0.596) strength test parameters could predict the DP performance significantly. This study showed that standardized isokinetic strength tests could be used to estimate pole force capabilities of XCS athletes. However, pole-force and strength test parameters failed to predict significantly maximal velocity during a DP sprint exercise, which might be attributed to the non-elite subject group.


Assuntos
Desempenho Atlético/fisiologia , Destreza Motora/fisiologia , Força Muscular/fisiologia , Esqui/fisiologia , Adulto , Cotovelo/fisiologia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Análise de Regressão , Ombro/fisiologia , Torque , Tronco/fisiologia
20.
Sensors (Basel) ; 19(24)2019 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-31847427

RESUMO

No matter your experience level or budget, there is a great ski goggle waiting to be found.Goggles are an essential part of skiing or snowboarding gear to protect your eyes from harsh environmental elements and injury. In the ski goggles manufacturing industry, defects, especially on the lens surface, are unavoidable. However, defect detection and classification by visual inspection in the manufacturing process is very difficult. To overcome this problem, a novel framework based on machine vision is presented, named as the ski goggles lens defect detection, with five high-resolution cameras and custom-made lighting field to achieve a high-quality ski goggles lens image. Next, the defects on the lens of ski goggles are detected by using parallel projection in opposite directions based on adaptive energy analysis. Before being put into the classification system, the defect images are enhanced by an adaptive method based on the high-order singular value decomposition (HOSVD). Finally, dust and five types of defect images are classified into six types, i.e., dust, spotlight (type 1, type 2, type 3), string, and watermark, by using the developed classification algorithm. The defect detection and classification results of the ski goggles lens are compared to the standard quality of the manufacturer. Experiments using 120 ski goggles lens samples collected from the largest manufacturer in Taiwan are conducted to validate the performance of the proposed framework. The accurate defect detection rate is 100% and the classification accuracy rate is 99.3%, while the total running time is short. The results demonstrate that the proposed method is sound and useful for ski goggles lens inspection in industries.


Assuntos
Dispositivos de Proteção dos Olhos , Esqui , Algoritmos , Humanos
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