Ski Bindings Research Articles

NEW SKIING TECHNIQUES – NEW INJURIES? ANALYSIS OF SKI INJURIESIN 2004/2005

BACKGROUND New developments in ski technology have influenced the rate and structure of ski injuriesin the past. Lately, skies and snowboards with carved steel edges have taken over traditionally shaped skies and introduced a new, so called »carving« technique. In this paper weanalysed ski injuries treated at Department of Traumatology during 2004 and 2005, tosee whether new equipment and skiing techniques have changed injury rate and pattern. RESULTS The rate of ski injuries has not changed importantly while the pattern is quite different. Thenumber of high velocity and high energy injuries has raised, leading to higher number ofhead, trunk and multiple injuries. Number of upper extremity injuries has raised predominantly due to snowboarding. Carved edges and carving led to some new tipical mechanisms of injuries to the knee and upper tibia. CONCLUSIONS New design of skies and snowboards with carved edges have changed skiing technique.The velocity of skiers has raised, ski-tracking is defined by radius of ski edges and decreasedabillity to decelerate or to change direction in carving have led to new injury patterns. Newmechanisms of injuries dictate changes of security measures such as new release systemsof ski bindings, protection braces, skiing technique improvements and improved resortmanagement and safety

Do Sleep Disorders Have an Impact on Blood Pressure?

In this article, the relationship, perhaps interdependence, between sleep-disordered breathing, hypertension, and obesity is discussed. There is strong evidence that sleep-disordered breathing and hypertension are related. On the one hand, the prevalence of hypertension increases with the number of apnea-hypopnea episodes per hour of sleep, whereas on the other hand, treating sleep-disordered breathing reduces hypertension. It has also been shown that this relationship between sleep-disordered breathing and hypertension is stronger in individuals with a high body mass index. Thus, it is concluded that in individuals presenting with hypertension, sleep-disordered breathing, or increased weight, the two other variables must be investigated and treated if present.

Review of Research Literature on Snowboarding Injuries as Might Relate to an Adjustable/Releasable Snowboard Binding

Abstract The issue of an adjustable releasable binding for snowboard skiing has been the subject of comment for many years. This literature review covers a total of 24 papers, one presentation, and one previously unpublished data source (total of 26 references); they range from the earliest known study to the most recent known survey as of July 2006. There are numerous other papers that deal with various aspects of snowboard injuries, but it was judged that they did not have any significant bearing on the issue of a release binding, and thus we have not included them in this review. The purpose of the review is to examine the available peer-reviewed research literature on this topic with the purpose of identifying injury patterns and mechanisms of injury that would be amenable to mitigation by means of an adjustable releasable binding. The main conclusion is that the risk of tibia fracture (as determined in absolute terms using MDBI) is significantly higher for skiing than for snowboarding, even though ski bindings have a release capability and snowboard bindings by-and-large do not. The current concept of releasable/adjustable snowboard bindings appears to be based in large measure on the releasable/adjustable alpine ski bindings. This conclusion is based on the observation that the primary release mechanisms are substantially the same, i.e., lateral at the toe and vertically at the heel. The only known standards testing ever done of a snowboard binding (Meyer) used Alpine ski binding evaluation methods. To the best of our knowledge, no snowboarding binding manufacturer has ever explicitly expressed anything to the contrary; i.e., the model of protection is different from Alpine ski bindings. Thus the only logical conclusion is that the release function of the snowboard binding would be the same for snowboarders as the release function of Alpine ski bindings is for skiers; i.e., protection of the mid-shaft region of the tibia. As of the time of this review, there have been no scientific studies performed (or published) to demonstrate whether releasable snowboard bindings would have any effect on injury rates in snowboarding in general or for any specific injury. The many published studies on snowboard injury rates, alone or compared to Alpine skiing injuries, have led to significant speculation that releasable snowboard bindings would not decrease injury rates, and that they might perhaps increase injury rates in snowboarding. Appropriate scientific studies are required to demonstrate their potential effectiveness. There does not seem to be any biomechanical or epidemiological evidence (either relative in terms of percent of all injuries, or absolute in terms of MDBI) that releasable bindings for snowboards would be likely to reduce the incidence of injuries that are significantly controlled for with Alpine ski bindings, and therefore this review does not lend support to the proposition that a releasable binding similar to current Alpine ski bindings should be a recommended practice for snowboarding.

An Advanced High Modulus (HMG) Short Glass-Fiber Reinforced Nylon 6: Part I - Role and Kinetic of Fiber-Glass Reinforcements

Recent developments were oriented on two high flow, high modulus fiber-glass reinforced nylon 6 (HMG series) grades for automotive and other industrial applications requiring high stiffness and high strength. These materials combined the following improved technological (injection molding, vibration welding, etc.) and mechanical performance properties such as greater dimensional stability, higher short-term (strength and stiffness) and long-term (fatigue and creep). The current and possible applications of these plastics includes auto mirror housing brackets, clutch pedals, clutch master cylinders, ski bindings, steering wheels, levers, auto seat frames, door handles and door lock mechanisms. In Part I of this paper, we are presenting results of reinforcement analysis with the influence of level of loading and geometrical parameters of used fiber-glass.

An Advanced High Modulus (HMG) Short Glass-Fiber Reinforced Nylon 6: Part II - Mechanical Performance

Recent developments were oriented on two high flow, high modulus grades fiber-glass reinforced nylon 6 (HMG series) grades for automotive and other industrial applications requiring high stiffness and high strength. These materials combined the following improved technological (injection molding, vibration welding, etc.) and mechanical performance properties such as greater dimensional stability, higher short-term(strength and stiffness) and long-term(fatigue and creep). The current and possible applications of these plastics includes auto mirror housing brackets, clutch pedals, clutch master cylinders, ski bindings, steering wheels, levers, auto seat frames, door handles and door lock mechanisms. In Part I of this paper, we presented results on the role and kinetic of reinforcement with the influence of level of loading and geometrical parameters of used fiber-glass. In Part II of this paper, we are presenting results on short-termand long-term mechanical performance of developed high modulus reinforced plastics.

Structural Mechanism of Smad4 Recognition by the Nuclear Oncoprotein Ski: Insights on Ski-Mediated Repression of TGF-β Signaling

The Ski family of nuclear oncoproteins represses TGF-β signaling through interactions with the Smad proteins. The crystal structure of the Smad4 binding domain of human c-Ski in complex with the MH2 domain of Smad4 reveals specific recognition of the Smad4 L3 loop region by a highly conserved interaction loop (I loop) from Ski. The Ski binding surface on Smad4 significantly overlaps with that required for binding of the R-Smads. Indeed, Ski disrupts the formation of a functional complex between the Co- and R-Smads, explaining how it could lead to repression of TGF-β, activin, and BMP responses. Intriguingly, the structure of the Ski fragment, stabilized by a bound zinc atom, resembles the SAND domain, in which the corresponding I loop is responsible for DNA binding.

Self-release of ski-binding.

We investigated whether twenty-five male and female downhill skiers of different ages (11 - 63 years) and skiing skills were able to self-release their ski binding by an inward twist of the foot and leg. We also studied possible correlations between thigh muscle torques and the ability to release the binding. All subjects used the same ski and binding, Marker Titanum M48, individually set according to weight, height, skiing skill, age, and boot sole length. Prior to the test we used a special torque wrench, the Vermont Release Calibrator, to verify that the settings of the binding corresponded to the appropriate torque (Nm) to produce a release. Isokinetic concentric and eccentric quadriceps and hamstring torques were measured. EMG was used to study which muscles are engaged in this self-test. Nineteen skiers were able to release the binding, while four children and the two muscularly weakest skiers were not. The medial hamstrings produced the highest degree of muscle activity during the inward twist release of the binding. There was a highly significant correlation between thigh muscle torques and the ability to release the binding.

Anterior cruciate ligament injury in recreational alpine skiers: analysis of mechanisms and strategy for prevention

Between 1995 and 1997, a retrospective survey was conducted in Japan to classify the types of injuries sustained by recreational alpine skiers. The purpose of this study was to investigate the causes and mechanisms of lower-extremity equipment-related (LEER) anterior cruciate ligament (ACL) injury in this population. Seventy-seven (96%) of the 80 respondents reported that their ski bindings did not release their ski boots at the time of their accident, and 30 respondents (38%) reported functional failure of their ski bindings, or that the ski boots came off. By presenting this investigation, we hope to give sports medicine clinicians a better understanding of LEER injuries and insights into how to prevent such injuries.

Preventing alpine skiing injuries – how effective are the countermeasures?

Aim The aim of this review was to determine the extent to which the effectiveness of countermeasures for preventing alpine skiing injuries has been evaluated. Methods The methodology involved a critical review based on the available international literature and sports equipment standards, as well as consultation with experts in the field. Where possible, the review focused on controlled trials. Results Key injury countermeasures in skiing identified in this review include physical conditioning programmes, ski-bindings and their timely release, professional adjustment of ski-bindings and the use of mechanical testing devices for this, design of ski pole handles, helmets for children (and adults), ski patrollers, skier education, speed control on the slopes and safe lifting equipment. A tabular categorisation of the types of evidence for the effectiveness of injury countermeasures is presented. This demonstrates that the weight of evidence is generally based on a combination of data-based or biomechanical testing evidence and informed opinion/anecdotal evidence. There is minimal evidence based on controlled trials in the field. The most evaluated countermeasures are ski bindings and ski pole handles. Properly adjusted ski bindings have the potential for a 3.5-fold reduction in lower extremity injuries, particularly knee injuries. Ski pole handle design needs further innovation and attention. An immediate concern is the generally poorer standard of children’s equipment, ski bindings and their adjustment. Conclusion Skiing is a sport that is growing in popularity, but with a need for controlled trials of its injury prevention countermeasures. This review provides a basis for further action in injury prevention research, development and implementation.

Alpine ski bindings and injuries. Current findings.

In spite of the fact that the overall incidence of alpine ski injuries has decreased during the last 25 years, the incidence of serious knee sprains usually involving the anterior cruciate ligament (ACL) has risen dramatically since the late 1970s. This trend runs counter to a dramatic reduction in lower leg injuries that began in the early 1970s and to date has lowered the risk of injury below the knee by almost 90%. One of the primary design objectives of modern ski boots and bindings has been to protect the skier from tibia and ankle fractures. So, in that sense, they have done an excellent job. However, despite advances in equipment design, modern ski bindings have not protected the knee from serious ligament trauma. At the present time, we are unaware of any binding design, settings or function that can protect both the knee and lower extremities from serious ligament sprains. No innovative change in binding design appears to be on the horizon that has the potential to reduce the risk of these severe knee injuries. Indeed, only 1 study has demonstrated a means to help reduce this risk of serious knee sprains, and this study involved education of skiers, not ski equipment. Despite the inability of bindings to reduce the risk of severe knee injuries there can be no doubt that improvement in ski bindings has been the most important factor in the marked reduction in incidence of lower leg and ankle injuries during the last 25 years. The authors strongly endorse the application of present International Standards Organisation (ISO) and American Society for Testing and Materials (ASTM) standards concerning mounting, setting and maintaining modern 'state of the art' bindings.

The Effectiveness of Ski Bindings and Their Professional Adjustment for Preventing Alpine Skiing Injuries

This article presents a critical review of the extent to which alpine ski bindings and their adjustment have been formally demonstrated to prevent injuries. It considers a range of evidence, from anecdotal evidence and informed opinion to biomechanical studies, testing of equipment, epidemiological studies and controlled field evaluations. A total of 15 published studies examining the effectiveness of bindings and their adjustment were identified. All of these included anecdotal or informed opinion, and all but one focused on equipment design. Seven studies involved the testing of bindings or binding prototypes, 2 studies presented biomechanical models of the forces involved in binding operation, 6 reported an epidemiological evaluation of ski bindings and 2 considered skiers' behaviours towards binding adjustment. Some of the reviewed articles relate to the study of the biomechanics of ski bindings and their release in response to various loads and loading patterns. Other studies examined the contribution of bindings and binding-release to lower extremity, equipment-related injuries, the effect of various methods of binding adjustment on injury risk and the determinants of skiers' behaviour relating to professional binding adjustment. Most of the evidence suggests that currently used bindings are insufficient for the multidirectional release required to reduce the risk of injury to the lower limb, especially at the knee. This evidence suggests that further technical developments and innovations are required. The standard of the manufacture of bindings and boots also needs to be considered. The optimal adjustment of bindings using a testing device has been shown to be associated with a reduced risk of lower extremity injury. Generally, however, the adjustment of bindings has been shown to be inadequate, especially for children's bindings. Recommendations for further research, development and implementation with respect to ski binding and their adjustment are given in this article.

Electromechanical Ski Release Binding With Mechanical Backup

To better protect Alpine skiers against injuries to both the lower leg and the knee, the objective of this work was to design a binding which: (1) maintained a consistent release level in twist in the presence of combined loads; (2) released the heelpiece based on the anterior/posterior (A/P) bending moment transmitted by the leg; and (3) modulated the release level in twist depending on the degree of contraction in muscles crossing the knee. To fulfill the objective, a conventional ski binding was modified. Modifications included integrating dynamometers into the toepiece, anti-friction device (AFD), and heelpiece. The toepiece sensor indicates the twisting moment while the AFD and heelpiece sensors indicate the anterior bending moment transmitted by the leg. To gain electronic control of binding release, a solenoid actuated mechanism was added which translated the heelpiece rearward along the ski to decouple the boot from the binding. Otherwise, the binding allowed normal mechanical function. Prototype testing confirmed the ability of the dynamometers to accurately measure desired loads in the presence of extraneous loads and the reliability of the solenoid actuated mechanism in releasing the hoot under loads typical of skiing. Thus, this work demonstrated the feasibility of hybrid electromechanical/mechanical releasable bindings. Such a demonstration should encourage the development of designs for commercial use.

Experts Try Education to Preserve Skiers' Knees

BY TOO many accounts, one of the most horrible sounds a skier can hear on a ski slope is the popping noise of the anterior cruciate ligament (ACL) as it tears during a fall. That sound, which usually heralds a painful, debilitating, and expensive knee injury, is heard no less by the most accomplished skiers than by the clumsiest novices. Severe knee sprains are now the most common medically significant injuries among Alpine or downhill skiers. While improvements in ski boots and bindings since the 1970s have greatly reduced fractures and other injuries below the knee, they appear to have done nothing to protect skiers from serious ACL injuries. According to several studies, the rate of severe knee sprains—which usually involve the ACL—has increased more than threefold since the late 1970s. Now, researchers who have spent more than two decades studying video tapes of ski injuries have developed an educational

スキーヤーの転倒事故の責任とリスクマネジメントに関する事例研究

The purpose of this study is to identify current problems concerning the responsibility for skiers'falling accidents and to relate these problems to documents concerning the setting values of ski bindings recorded for some skiing accident cases in Japan. In this study the following problems have been singled out for emphasis: (1) Up to now an overwhelming majority of ski shops and rental ski shops in Japan have no system for keeping records of the setting value of the ski bindings for purposes of avoiding liability related to skiers' accidents. (2) There are no systems in place to help obtain information from incident reports concerning the ski bindings when skiing accidents occur at ski areas. (3) It is also the case that there are no data regarding the settings of ski bindings of injured skiers, thus making the determination of liability extremely diffi cult. The Product Liability Law has been in effect from July 1995 in Japan. The Association of Ski Bindings Sellers has decided to import a system for documenting the setting values and to keep a copy when ski shops sell skis to customers. The system will be put to the test in the'95-'96 ski season. The documents concerning the setting values of ski bindings should be consid ered when reviewing an organization's overall risk management program.

Anterior cruciate ligament injury in elite Alpine competitors

Balance in Alpine skiing is dynamic and tenuous. Loss of balance typically leads to the accumulation of forces that create severe bending moments at the knee. The modern ski binding, while effective at protecting the ankle and lower leg, is much less effective at protecting the knee. The result: knee injuries have increased nearly three-fold since 1972 with anterior cruciate ligament (ACL) injuries currently accounting for approximately 10% of all skiing injuries. The mechanism of ACL injury in elite competitors is distinct from recreational skiers and is typically associated with a characteristic, deeply flexed, seated body position, with the feet accelerating forward relative to the upper body. The risk of ACL injury in elite skiers is compounded by the functional characteristics of the modern ski binding and further exacerbated by the protocols used to set release tension for competition. It is apparent that the physical abilities of the elite competitor, combined with modern ski technique and equipment, expose the skier to forces that the human body cannot tolerate. Presently, the only solution to the problem would appear to be the development of "smarter" bindings and/or the adoption of standards that set limitations on performance for the sake of safety.

Pulmonary microembolisation and temazepam.

<h3>Objectives</h3> To evaluate the impact of ski geometry data and standing height ratio on anterior cruciate ligament (ACL) injury risk of male and female recreational skiers. <h3>Methods</h3> A retrospective questionnaire-based, case–control study of ACL-injured and uninjured recreational skiers was conducted during six consecutive winter seasons. Ski geometry data (ski length, side-cut radius, widths of the tip, waist and tail) were recorded from each participant’s skis. Standing heights at the front and rear components of the ski binding were measured with a digital sliding calliper, and the standing height ratio between the front and rear was calculated. <h3>Results</h3> A total of 1817 recreational skiers participated in this study, of whom 392 (21.6%) sustained an ACL injury. Multiple logistic regression analysis indicates a higher age, a lower skill level and riskier behaviour as independent individual risk factors associated with an ACL injury. An increase in ski length, tip width of the ski, standing height at the rear ski binding component, and in standing height ratio were found to be independent equipment-related risk factors for an ACL injury. <h3>Conclusion</h3> Reduced ski length, narrower ski tip width, lower rear standing height and a lower standing height ratio (ie, rear component of the ski binding is more elevated compared with the front component) were associated with a reduced likelihood for ACL injury. When buying or renting skis, these parameters could be considered to reduce the likelihood of ACL injury in recreational skiers.

A New Electromechanical Ski Binding with Release Sensitivity to Torsion and Bending Moments Transmitted by the Leg

This paper describes the design of a new electromechanical ski binding whereby release in both twist and forward bending is controlled electronically and the release level in twist is modulated electronically based on the neural stimulation of muscles in the quadriceps group. To provide signals for controlling release in the two modes, the binding incorporates two dynamometers. Each dynamometer measures loads that have been shown to correlate strongly (r2&gt;0.90) to torsional and bending moments at the lower leg injury sites. Although the binding consists of both a toepiece and heelpiece, the toepiece does not permit release of the boot from the ski in the twist mode but rather serves as one of the dynamometers. Consequently the heelpiece was designed to provide the release function in both modes. Release is realized by a low-force solenoid that actuates a multilink trigger mechanism. To prove feasibility, a prototype was constructed and evaluated.

Trends in skiing injury type and rates in Australia: A review of 22 261 injuries over 27 years in the Snowy Mountains

To show the trends in the rate and type of skiing injuries in Australia. A retrospective analysis of skiing injuries in the Snowy Mountains from 1962 to 1988. All injuries were seen and treated at the Ski Injury Clinic in Perisher Valley. A total of 22,261 injuries were seen over this 27 year period (data for 1963, 1964, 1966, 1977, 1978, 1981 and 1982 were missing). Injured skiers were treated at the Clinic with a small number sent to main centres for tertiary care. The overall injury rate (1962-1988) and the specific injury rate for six subgroups of injuries (1974-1988) were calculated. The overall injury rate declined dramatically over this period. The incidence of tibial fractures, ankle injuries and lacerations also declined. Upper body injuries continue to rise although this trend was not statistically significant. There was a statistically significant increase in knee injuries. The trends reported here are similar to those overseas except that the incidence of thumb injuries has not changed in Australia. The changes in the rates of lacerations, and tibial and ankle injuries can be related to improvements in ski bindings and boots.

An Alpine Ski Binding with Electrically Modulated Twist Release

This article describes the design of a new binding for Alpine skiing wherein the release level of the toepiece in twist is modulated based on the level of neural stimulation of one of the vastii muscles in the quadriceps group. A conventional binding toepiece that relies on the force of a compressed spring to resist the release of the boot was modified. To modulate the release level to either a high or a low state, a special solenoid activated mechanism that alters the binding spring constant was designed. The design details of this special mechanism are described and the computations necessary to ensure reliable activation with a low force solenoid are summarized. Also described is the special circuitry that was designed to actuate the solenoid. To demonstrate the workability of both the mechanism and the circuitry, a prototype binding system was constructed and tested. The results of this testing are described as well.

Military Nordic Skiing Injury Profiles with Two Different Types of NATO Ski Bindings

Two different types of NATO ski bindings were compared during military-nordic ski training of a Marine Corps infantry battalion of 534 men, who sustained 26 injuries (3.75 injuries per 1,000 skier days). Twelve injuries occurred with the 224 subjects using the NATO 100 bindings. Fourteen injuries occurred with the 310 subjects using the NATO 120 bindings. A total of 133 days were lost from training in the NATO 100 cohort and 121 days from training in the NATO 120 cohort, a statistically significant difference. It is concluded that the NATO 120 binding is safer.