Review of Injury Countermeasures and their Effectiveness for Cross-Country Skiing

Monash University Accident Research Centre - Report #100 - 1996

Authors: H. Kelsall & C. Finch

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Abstract:

Cross-country skiing is a popular alpine sport. It can be one of the most physically demanding of all sports, involving most of the body's muscles, and requiring a sustained cardiovascular and respiratory output. It is also ideal as a recreational sport, and can be enjoyed by individuals of all ages. Cross-country skiing includes ski-touring, defined trail skiing using the diagonal stride or skating techniques, and cross-country/downhill skiing. Cross-country skiers have been estimated to account for approximately 20% of all participants in alpine sports. The most common type of cross-country skiing injuries are sprains/twists, fractures and bruises. The most frequently injured body regions are the knee, arm/hand and the ankle. Risk factors for injury include poor condition of ski tracks; unsuitable or inferior equipment; poor balance, inadequate mastery of the cross-country skiing technique and overuse. The aim of this report is to present a critical review of the extent to which the effectiveness of cross-country skiing injury countermeasures has been evaluated and to make recommendations for further research, development and implementation. Countermeasures specifically reviewed in this report include: ski pole handle design, ski bindings and equipment, skiing technique, pre-season conditioning, ski lessons, clothing, adequate nutrition and reduced alcohol intake, standards for skiing equipment, environmental factors, ski patrollers, first aid, rescue equipment and general resort safety. Little is known about cross-country skiers, their characteristics, aetiology and injury patterns, equipment related factors and the relationship between injury patterns and causal factors such as skiing ability, equipment, snow conditions and terrain. Some cross-country injuries are similar to those among alpine skiers. This suggests that countermeasures that have been effective in preventing alpine injuries, such as improvements in equipment design, may also prevent cross-country injuries. More attention needs to be directed towards preventing cross-country injuries, including data collection and epidemiology studies of injury patterns, studies of the mechanisms of injury and the safety of equipment.

Executive Summary

Introduction

Cross-country (or Nordic) skiing is a popular sport in which there is a broad range of standards and ages of skiers. Cross-country skiing can be one of the most demanding of all sports, involving most of the body's muscles, and requiring a sustained cardiovascular and respiratory output. It is also ideal as a recreational sport, and can be enjoyed by individuals of all ages.

Cross-country skiing includes ski-touring (usually skiing away from defined resort areas), defined trail (or track) skiing using the diagonal stride or skating techniques, and cross-country/downhill skiing (combined with ski touring or sometimes on the regular ski runs). Equipment has been designed to suit the particular requirements of each type. As a sport, cross-country skiing has developed considerably since the 1980s with improvements in technology and design of equipment and clothing. There has been considerably less research on the epidemiology of cross-country skiing injuries or on evaluation of countermeasures to reduce injuries than there has been in alpine skiing.

Cross-country skiers have been estimated to account for approximately 20% of all participants in alpine sports. In a 1985 Australian study, the cross-country skiing injury rate was 0.49 injuries per 1000 skier days, while the alpine injury rate was 3.54 per 1000 skier days. Whilst the incidence of skiing injuries is lower in cross-country than alpine skiing, there is evidence to suggest that the severity of injuries may be comparable. The most common type of cross-country skiing injuries are sprains/twists (43%), fractures (25%) and bruises (18%). The most common body locations are the knee (26%), arm/hand (13%), and the ankle (12%). Risk factors for injury, especially amongst recreational skiers, include poor condition of ski tracks (deep tracks, ruts, iciness, sharp bends etc) and the downhill segment of terrain; unsuitable or inferior equipment (slippery glass fibre skis, wrong type of wax, boot not matched to the skiing style, etc); poor balance and inadequate mastery of the cross-country skiing technique.

The aim of this report is to present a critical review of the extent to which the effectiveness of injury countermeasures for cross-country skiing have been evaluated, consider the results of such evaluation and the level of supporting evidence, and make recommendations for further action in injury prevention research and practice. Measures to prevent or control injury, ie injury countermeasures can be targeted toward primary (pre-event), secondary (event) and tertiary (post-event) prevention in the chain of injury events. Primary countermeasures for cross-country skiing include pre-season conditioning and fitness programs and adequate warm ups, skiing technique, equipment factors (skis, boots, bindings, ski poles, eye wear, clothing, helmets), adherence by skiers to the skiers' safety and courtesy codes, ski patrollers, adequate nutrition and fluid intake, environmental factors (condition and design of ski trails), skier education programs, skiing instruction and expertise of instructors, adequate supervision of children, and use of safety equipment. Secondary countermeasures include protective equipment (helmets, eye wear), skiers conduct code and speed control, general sports equipment (ski pole handle design, standard of bindings, ski boots), condition of ski trails and environmental factors. Tertiary countermeasures include location of injured skiers, availability of first aid equipment; ski patrol assessment, treatment and transport; access to medical care; and adequate treatment and rehabilitation of injuries before resumption of skiing.

The following sections describe the major countermeasures reviewed and give the recommendations for further research, development and implementation.

Ski Pole Handle Design

Injuries to the thumb are the most common upper extremity injury in skiing. The injuries can occur in all directions of fall, although a forward fall is more commonly reported. Retention of the ski pole in the hand during a fall is the major cause of this type of injury. Ski poles (or stocks) are carried by both cross-country and alpine skiers. Ski poles used by cross-country skiers are longer and have narrowed handles, compared to alpine ski poles. Skiers use them to push themselves along on the flat or uphill and as part of the skiing turn. The research on ski pole handle design has been done in relation to alpine skiing. Although the identified and reviewed studies relate to alpine ski pole handle design, there are significant implications for injury prevention in cross-country skiing and further attention to cross-country ski pole handle design is warranted.

Recommendations for further research, development and implementation

  • Further research into the design of ski pole handles and ski straps is needed.
  • Further research into the design of ski gloves.
  • Controlled evaluations of both ski pole handles and ski glove designs in the field are required.
  • An assessment of correct falling techniques and consideration of what is taught by ski schools in relation to this should be made.
  • There should be continued support for a high standard of ski patrol services to provide a rapid response and safe transport of injured skiers.
  • Specific advice, or training, for doctors in and around ski field areas, about the examination, management and rehabilitation of thumb and shoulder injuries needs to be developed and promoted.

Ski Bindings and Equipment

Ski bindings and boot design are particularly relevant to lower limb injuries. The heel position is not fixed, and bindings are not designed to release. Convertible or cable bindings or heel plates that stabilise or fix the heel during turning and skiing downhill can provide better control, but may increase the risk of injury, with the ski acting as a lever about which the knee twists. Releasable cross-country bindings are reputably being developed, but as in alpine skiing, safe design and reliable performance criteria need to be met if they are to assist in injury reduction. The choice of ski boot depends on the cross-country skiing activity for which they will be used, eg touring, racing or skating, but should be flexible at the forefoot and allow free motion at the ankle.

Recommendations for further research, development and implementation

  • Further research into the mechanisms of lower extremity injuries is needed.
  • Detailed studies of the potential role of releasable cross-country bindings are warranted before they are widely promoted.
  • Monitoring of injury trends as new equipment becomes available.
  • Education of cross-country skiers about the most appropriate equipment for their type of cross-country skiing.

Skiing Technique

During the mid-1980's the skating technique largely replaced the traditional diagonal striding as a racing technique and revolutionised the sport. The upper body plays a more propulsive role in cross-country skiing than alpine skiing, and more so in the skating that diagonal striding technique. Overuse injuries can consequently be a problem.

Recommendations for research, development and implementation

  • Monitor overuse injury trends, particularly in competitive skiers.
  • Encourage adequate preparation and warm-up before skiing.
  • Include consideration of the potential for overuse injuries and their prevention in training programs.

Pre-Season Conditioning

Cross-country skiing is a physically demanding sport. Skiing requires muscle endurance, strength, flexibility and cardiopulmonary fitness. Whilst highly trained athletes (racers) and experienced skiers still have injuries, the recreational skier with low skills and inadequate physical preparation may be at greater risk.

Recommendations for research, development and implementation

  • Additional research into the effectiveness of conditioning programs on the prevention of skiing injuries is required.
  • A more rigorous evaluation of the impact and health outcomes of the Australian Physiotherapy Association's "Get Fit to Ski with Physiotherapy" program should be undertaken.
  • Specific conditioning programs for cross-country skiers should be investigated.

Ski Lessons

Ski lessons are available at most Australian resorts. A number of epidemiological studies of injuries among alpine skiers have considered the association of ability, and sometimes a history of having taken ski lessons, with injury rates. Similar studies have not been done with respect to cross-country skiing, but the results are reported here because similar principles apply to cross-country skiing. The role of skiing instruction in preventing injuries is controversial, and it is considered that skiing lessons must be coupled with experience to have positive effect. The reviewed literature suggests that beginners and less experienced skiers have a higher risk of injury than advanced or intermediate skiers. The effect of ski lessons on the injury rates of intermediate or advanced skiers is less obvious. Ski lessons have other advantages including orientating skiers to the use of lifts, social contact and fun, the resort and it's layout, suitable slopes for their ability and other safety measures. The effectiveness of ski lessons as a countermeasure, however, has not been evaluated in a formal, controlled way, especially for cross-country skiers.

Recommendations for research, development and implementation

  • There should be standardisation of epidemiological data collection and reporting systems for categories of skiing ability and history of ski lessons in future studies.
  • Controlled studies to evaluate the effectiveness of ski lessons for injury prevention should be undertaken.
  • A review of the content of ski lessons with respect to skiing safety should be undertaken.

Clothing

Clothing serves several purposes in alpine conditions, including protection from a variety of weather conditions such as snow, sleet or rain, high winds, poor visibility, brilliantly sunny days and strong reflective glare. Clothing that is inadequate in providing warmth and wind factor protection can leave the skier at risk of hypothermia and frostbite. Consideration of clothing design and injury is an area that warrants particular attention to consumer acceptance.

Recommendations for research, development and implementation

  • Continue to improve the materials for skiing garments and eyewear.
  • Consider manufacturing clothing with higher coefficients of friction.
  • Continue to reinforce the essential and protective aspects of clothing to skiers.
  • Continue to encourage the use of protective sun screen.
  • Consider a specific review of children's clothing and eyewear.

Adequate Nutrition and Reduced Alcohol Intake

Injuries are more likely to occur at certain times of the day, such as late morning and late afternoon, and fatigue at such times may contribute to the risk of injury. Adequate rest, nutrition and energy replenishment are also likely requirements for both enhanced performance and injury prevention.

Recommendations for research, development and implementation

  • Reinforce the importance of good nutrition and adequate carbohydrate replenishment during skiing.
  • Conduct preliminary studies on the alcohol consumption patterns of Australian skiers, and cross-country skiers more specifically, to determine the extent to which it is a factor in injuries.
  • Undertake controlled studies on the relationship between alcohol consumption and injury occurrence.

Standards for Skiing Equipment

No standards relating specifically to cross-country skiing equipment were identified through this review.

Recommendations for further standards development

  • A review of Australia's policy regarding skiing equipment and requirements in relation to equipment standards should be undertaken.
  • A review of Australia's policy regarding training and standards for ski shop personnel, ski binding fitting and adjustment in retail and hire outlets needs to be performed.
  • Based on the results of these two reviews, Australian policies may need to be reviewed.

Environmental Factors

Cross-country skiers often ski away from resort areas, alpine ski slopes and established trails. However, an increasing number of skiers are seen to be telemarking down ski runs. Environmental factors are important in both alpine and cross-country skiing. Ski patrols report that they use injury data collected throughout the season to monitor injury rates and take targeted remedial action if particular patterns are appearing. The effectiveness of various methods of hazard identification and mitigation have not been formally evaluated. Standardisation of policies and methods for hazard identification and mitigation and injury severity scores assist in comparisons of techniques and resort areas, and the monitoring of the effectiveness of interventions.

Recommendations for further research, development and implementation

  • Standardisation of policies and methods for hazard identification and mitigation
  • Consider a pilot test and validation of the calculation of injury severity scores and corrected injury severity scores to aid in ongoing assessment of slopes.
  • More formal evaluation of the effectiveness of hazard identification and mitigation in injury reduction is needed.
  • Continued support for the ski patrol role in the identification and removal of hazards.
  • Attention to cross-country skiing injuries in data collections and identification of those that occur on resort ski runs.

Ski Patrollers, First Aid, Rescue Equipment and Resort Safety

The organisation of emergencies services, selection and maintenance of equipment, administration of first aid treatment, transport and the use of trained personnel have been identified as important aspects of a service to administer first aid to skiers. Ongoing injury surveillance (especially by ski patrollers) can identify slopes or trails where a number of injuries have occurred and assist in focusing hazard identification and mitigation and injury prevention. Action may involve advice to resort management, a speed control program, promotion of safety helmets, trail or ski run closure, signage or obstacle markers or avalanche danger control. Ongoing surveillance can also assist in evaluating the effectiveness of interventions.

Recommendations for further research, development and implementation

  • Standardise data collection by ski patrollers and all Australian ski resorts and include information on weather and snow conditions and terrain.
  • Review the incident/injury report forms used by ski patrollers to maximise the use of information for injury research and monitoring, with particular attention to cross-country skiing injuries.
  • Consider methods for the collection of injury severity data and the potential for standardisation of this.
  • Standardise the age groups used for statistical comparisons in the analysis and reporting of injury data.
  • Further develop injury surveillance programs for a range of snow sports.
  • The standardisation of data collection across all Australian resorts would provide an improved data base for research, statistical comparisons, surveillance, the monitoring of injury trends and evaluation of the effectiveness of interventions or injury control programs.
  • Continue to support the Ski Patrol Association.
  • Make available at least one Global Positioning System unit at all ski resorts.
  • Investigate making alerting devices, eg mobile phones or transmitters, available to skiers to alert ski patrols and to identify location if lost or injured.
  • Continue to promote safe driving in the mountains.

Conclusions

The technology and techniques of cross-country skiing have developed at a rapid pace over the last 10 years, but cross-country injuries have not been subjected to the same degree of research and countermeasure development as alpine skiing injuries. Studies on cross-country skiing injuries are complicated by the lack of a large injury data base, little information about the population at risk and smaller numbers of skiers and injury cases for comparative purposes and trend analysis.

Cross-country skiing injuries, the bio-mechanical and equipment related factors and epidemiological data, have not been as well studied as alpine skiing. Little is known about cross-country skiers, their characteristics, aetiology and injury patterns, equipment related factors and the relationship between injury patterns as determined by epidemiological studies and causal factors such as skiing ability, equipment snow conditions and terrain. Some cross-country injuries are similar to those among alpine skiers. This suggests that countermeasures that have been effective in preventing alpine injuries, such as improvements in equipment design, may also prevent cross-country injuries. More attention needs to be directed towards cross-country skiing from a safety point of view, from data collection and epidemiology studies of injury patterns to the bio-mechanics of injury and the safety of equipment.

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