Download INTERSKI CONGRESS 2011 St Anton Am Arlberg

INTERSKI CONGRESS 2011
St Anton am Arlberg
`Flying without wings`
LECTURE ABSTRACT – EDUCATIONAL DEVELOPMENTS
“Know it, Understand it, Use it”
- Biomechanics
“Know it, Understand it, Use it” – Biomechanics
For Safer & more effective, Teaching & Coaching
Introduction:
The Irish Association of Snowsports Instructors, a member of ISIA and IVSI,
have formally incorporated specific biomechanics teaching in their snowsports training syllabus
since 2004. An understanding of safe and effective technique, separate from teaching
methodology is a key part of the training system. The Association has an unusually high starting
age, and average age, of its instructors going through the system. This presentation will outline
key biomechanical knowledge and understanding of snow sports that is, and can be used, to
teach more effectively and more safely with the older and very young clients. A particular focus
will be prevention of and safe reintroduction after, ACL injuries. This is the first time the Irish
Association has offered a presentation to Interski.
Biography:
The presenter teaches in St Moritz, is the first person to go through the Irish
curriculum, is a trainer in the Irish system, and is a former University Head of Sports Sciences,
principal lecturer in sports & physiotherapy biomechanics, and professor of sports biomechanics
and physical education. David Murrie. PhM, MEd, BSc, ISIA, IVSI.
Presentation: In the 2008/9 season 43% of all alpine World Cup skiers sustained some kind of
injury, with 23 of them were ruled out for at least eight days. This season has seen similar
statistics on injured racers, prompting FIS to commission new research on injury prevention The
change in ski equipment from traditional, to `carving` skis, seems not to have significantly
influenced injury occurrence in skiing generally, although male `experts` have suffered a slight
increase in knee injuries. It is possible that the shorter and more maneuverable mass-market skis
have benefited slower skiers, but the slow backward twisting fall is a common cause of knee
injuries. Further, knee injuries comprise approximately a quarter of all ski injuries, and 10% of all
injuries in snowsports are injuries to the Anterior Cruciate Ligament (ACL), with women more
susceptible than men. In a comparison of the top 30 skiers, an injury rate of 50% for ACL injuries
during 25 years of competitive skiing was found. Also, 26% of Austrian, female racers age I518yrs, have had at least one ACL injury. Performing sensory-motor (balance control) training,
actually in ski boots (i.e. with a fixed ankle joint) has recently shown to enhance early and more
powerful, protective activation of muscles around the knee (especially the important hamstrings)
in the event of forces that are tending to displace the knee forwards.
There is actually no evidence base though that `aerobic` fitness per se is significant in
performance or injury prevention, or that snowsports skill is founded on traditional conditioning
factors, but knee injuries have been related to deficits in muscular strength. There is moreover,
some evidence that eccentric muscle strength is important with increasing speed, and in
beginners. This was more recently refined to indicate proportionate strength and coordination of
the muscles crossing the front and back of the knee is important. Even in Giant Slalom ski turns
the eccentric phase for knee extensor muscles last twice as long as the concentric phase and the
eccentric action of the outside leg exceeds that of any concentric activity. Modern slalom
technique produces minimum knee angles of less than 60 degrees and high muscular activity
corresponding to low knee angles. Maximum eccentric contraction by knee extensors may in fact
be a limiting factor for the speed at which gates can be passed in racing. Moreover, recent
studies suggest that the muscle activity in slalom and GS are much closer than expected;
suggesting the efficacy of recent ski regulations needs further thought. The implications for
Eurotest training will also be examined.
Explanation of the Irish curriculum, useful biomechanics principles, appropriate fundamental
movement patterns, exercises and preventative conditioning, plus video of Irish Trainers in action
will be presented. Notes and copies of materials will be made available in English, German,
French and Italian at the presentation.