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  1. 1. Ski Biomechanics & Physiology Awareness <br />OVERVIEW Ski technique is a very popular subject in the world of skiing.  For many years technique has been put across to skiers getting usually moderate to great results.  With all tuition it's limited to what people's bodies can physically do.  Nearly all skiers have a weaker turn.  This is due to physical and mental limitations on one side of the body.  Because of this one side of the body usually absorbs the learning better and as a result a weaker turning direction is left.<br />This doesn't show itself generally if you're inside your comfort zone, but as soon as you ski faster, steeper and away from the piste the weaker turn becomes more apparent and will consistently let your technique down.  When flat light sets in, slopes become icy and you're feeling fatigued you'll also feel your weaker turn more.  When skiing on very steep or exposed faces, your weaker turn can actually put you in vulnerable situation as on these slopes you are truly only as good as your weaker turn!<br />Most skiers are always trying to improve their performance, speed, style and general grasp of the sport from your beginner right through to a competitor.  Quite a lot of the time improvement is slowed down by the weaker or restricted direction.  The job of a ski instructor would be a whole lot easier if he had a complete understanding of ski biomechanics and physiology.  The plateau's that are often talked about in skiing (normally intermediate plateau) usually boil down to handful of issues that are more times than not fixed by a combination of ski coaching, ski biomechanics and ski physiology exercises.<br />One other issue that ski biomechanics awareness can benefit is ski safety and injury prevention.  If you make turns that are symmetrical and generally equal, you'll become a more consistent skier.  This makes you a safer skier in all environments from the piste to big mountain.  Also, if you're skiing with better symmetry and actually know which muscles to drive the mechanical movements with, you'll reduce the risk of injury and damage to your skeleton and joints.<br />Overall, the true fact of the matter is that ski instruction is not as effective without the added factors of ski biomechanics and ski physiology.  It is our hope that more and more ski instructors across the globe will gain further education in these areas and better themselves so as to give out a much better product to the clients or athletes they work with.<br />  TYPICAL ISSUES IMPROVED WITH BIOMECHANICAL + PHYSIOLOGICAL AWARENESS<br />1.  CORRECT SKI LEG FLEX PATTERN (Unlocking the Ankles)Most skiers flex their knees more than their ankles.  This unfortunately causes body weight to rest consistently over the middle and back of the skis.  Also fatigues the thighs and puts strain on the knee joint.  Reasons for this are:a. Ski Boots perhaps too stiff b. Calf muscles perhaps too tightc. Over use of knee flex and knee flex as a habit (due to both of the above) <br />2.  SKIER SYMMETRY Most skiers ride from turn to turn with an a-frame shape in the legs. This is when the feet are wider apart than the knees.  This can happen by either the knees dropping in or the feet splitting out or both.  This makes the shape in the legs non symmetrical and the skis usually at different angles between the turns.  This can cause inconsistency between turns due to the skis being tilted at different angles.  This a-frame angle in the legs will put stress on the knee joints and tension in the muscles throughout the body.  An a-frame is one of the biggest factor behind skiers having problems in powder and variable terrains.  A-Frame's are usually more predominant on one direction.  The reasons A-frame's are so common are:a. Ski Boot set up (foot beds and canting)b. No awareness of lateral control musclesc. Ski technique issues such as pressure, edge and steering control<br />3.  INCREASE LEG STEERING RANGE - DECREASING UPPER BODY ROTATION Most skiers get told one time or another by a coach that there is too much upper body or hip rotation in their skiing.  This usually gives the skier a weaker edge support in the turn and poor body positioning over the skis.  The Result – A vulnerable and weaker set up for overall dynamic balance.  Upper body or hip rotation is usually more apparent in one direction.  Steering needs to come mainly from the legs with the ball of the thigh bone rotating inside the socket joint of the hips.  This allows the hips to remain generally facing in the direction of the fall line.<br />In most cases skiers can step their feet around approximately 50 or 60 degrees across either side from the fall line.  This means that when they steer from turn to turn and the steering of the skis is greater than say 50 or 60 degrees, the upper body will start to rotate as the skis try to achieve 75 degrees and 80 degrees of angle across the fall line (this is typically what’s needed of steeper slopes). The reasons for a poor leg steering range are:a.  General tightness in the hips b.  Lack of range in exterior and interior leg rotationc.  Many years skiing without finishing off of the turn shape <br />4.  POWDER STEERING THE SKIS (foot + thigh steering, not just foot)Most skiers have a good knowledge of steering the feet which usually gives an adequate result of steering the skis in each direction. However, not all skiers get educated on steering the thighs.  If thigh steering is added to foot steering, the overall process of the steering action is much stronger.  If muscles are more responsible for the steering action in the legs, it takes the torque out of the knee joint during the steering process. <br />Also, if skiers are wishing to ski and higher speeds, ride on steeper slopes and freeride on big mountain terrain it's essential that the power steering of the upper legs is switched on. The main reasons skiers don't use upper leg steering are: a. Foot steering usually being the only description of steering mentioned in a skiers first few weeks b. Lack of power and endurance in the upper leg steering muscles <br />5.  LATERAL ANGULATION (differences between leaning / falling left and right)If you watch video footage of most skiers in slow motion over 25 frames per second, you will nearly always see a difference between the angles skiers fall into with each turn direction.  Lean or Falling from the hips into each turn direction can be a technically demanding exercise.  Most skiers either lack confidence or lack range of movement falling towards the left or the right. <br />Usually we all favour either our left or right side of the body in many things in life.  Because of this when learning to lean the legs or fall with the hips in each direction, we will naturally fall to one direction and have a restriction to the other.  On the direction with the mental restriction you will normally see skiers leaning their head and shoulders across and not really moving the hip too much.  There is also a physical issue that can affect the falling in each direction which is being tighter in the muscle groups down one side of the body in the legs, hips and lower back.  Tightness in one side can restrict the range and speed someone can fall and lean their legs.<br />Main issuesa. Left and Right sides of the brain can make use favour falling / leaning the legs in one direction more than the other and actually make us lack confidence in one direction b. Tight muscles on one side of the body can make us lack range of movement and speed of movement for falling / leaning <br />6.   MIDDLE BODY CORE STRENGTH (activating core on the move)So many skiers spend most, if not all, of their time skiing from turn to turn with very little or no middle body strength.  If you ski with not much middle body and core strength you run the risk of allowing your hips (centre of your mass) to drop back during your turns.  This puts you out of balance and leaves your body weight on the tails of your skis.  Also when you’re skiing moguls and variable terrain you’ll often find that you’re constantly skiing into lumps of snow that cause there to be a sudden impact on the body.  If your middle body is weak with no core activation, you’ll find your upper body collapsing forwards as your body breaks at the waist. <br />To ski with middle body strength you need to learn how to activate you core and develop overall middle body strength and endurance.  This can be done by focusing on strength building exercises for your lower back and stomach muscles and your transverse abdominal (core) group of muscles.  Once you can become aware of how these muscles work you can then start to try skiing with them activated full time during your turns.  This is not as easy as it sounds and work off of snow is required to achieve full time core activation.<br />Main issues a. Most skiers ski without middle body strength and full time core activation making themselves vulnerable when performance levels are pushed or the conditions get more difficult b. Skiers can suffer from lower back compression injuries when skiing without a strong middle body <br />Solution is a. Dry land training to develop core strength and endurance.  This can be done by following some simple exercises given to you by professional fitness instructors b. Using a pre ski Core activation exercise to wake up the middle body and rehearse the position to hold it in when skiing.  This following explains:<br />1 Ski Biomechanics & Physiology Awareness <br />Primary Muscles Used for Skiing<br />What are the primary muscles used for downhill skiing? If you had asked this question 50 years ago, you would have received an entirely different answer. Back then, strength was a crucial element of alpine skiing. As such, the quadriceps, which are the strong muscles in the front of the thighs, would have been the primary muscles utilized. With the advent of straight skis, however, things began to change. Now skiing is considered more of a dynamic balance versus a strength-related sport. This has led to some changes in the primary muscles used when skiing. Related AdsSkiingSki TaosUtah Ski AreaSki ResortSki Vermont<br />The Core Musculature<br />Without good balance, skiing is virtually impossible. The deep core muscles are responsible for dynamic balance. These include the transverse abdominal muscle (the deepest core muscle), as well as the pelvic floor muscles, which support your internal organs. While the core muscles are not the prime movers of skiing movements, they are essential stabilizers.<br />The Feet and Ankles<br />You can't talk about ski technique without mentioning the kinetic chain, which refers to a sequence of events in a pattern of movements. When analyzing any series of actions, it's important to look at where the movement begins. Then you can begin to understand how these primary movements will affect all subsequent actions. In modern skiing, all moves begin in the feet and ankles. For example, the peroneus longus is involved in eversion and plantar flexion of the foot, while the tibialis is used for dorsi flexion. All of these movements are essential to carving the snowy terrain.<br />Gluteus Maximus<br />In skiing, the gluteus maximus functions as a hip extender. It also abducts, or pulls, the leg away from the center line of the body and stabilizes the knee when it is in an extended position. As such, the gluteal muscles are important for mogul skiing.<br />Quadriceps Muscles: Front of the Thigh<br />The rectus femoris extends the knee and flexes the hip. The vastus medialis performs the more subtle action of extending the knee. In modern skiing, it is used more frequently than the rectus femoris.<br />The Hamstrings: Back of the Leg<br />The hamstrings are perhaps one of the most important muscle groups in alpine skiing as they are involved in flexion of the knee. In skiing, they help absorb shock and protect the sensitive ACL.<br />Primary Muscles Used for Skiing |<br />Article Written By Lisa Mercer<br />In 1999, Lisa Mercer’s fitness, travel and skiing expertise inspired a writing career. Her books include " Open Your Heart with Winter Fitness" and " 101 Women's Fitness Tips." Her articles have appeared in " Aspen Magazine," " HerSports," " 32 Degrees," " Pregnancy Magazine" and " Wired." Mercer has a Bachelor of Arts in psychology from the City College of New York.<br />SKIING INJURIES<br />Skiing Injuries in Children, Adolescents, and Adults* <br />M. C. DEIBERT, M.D., D. D. ARONSSON, M.D., R. J. JOHNSON, M.D., C. F. ETTLINGER, M.S. and J. E. SHEALY, PH.D.#, BURLINGTON, VERMONT <br />Investigation performed at the Department of Orthopaedics and Rehabilitation, McClure Musculoskeletal Research Center, The University of Vermont College of Medicine, Burlington <br />We prospectively gathered data on skiing injuries that had been sustained at the Sugarbush North ski area since 1972 and at the Sugarbush South ski area since 1981. The purpose of the current study was to document the overall rates of injury in children, adolescents, and adults participating in alpine skiing. We also sought to determine the ten most common injuries in each age-group. Finally, we analyzed short-term and long-term trends to determine if changes in equipment had had an effect on the frequency or pattern of injury. From the 1981–1982 to the 1993–1994 season, there were 2.79 injuries per 1000 skier days: 4.27 injuries in children, 2.93 in adolescents, and 2.69 in adults. During the last eight years of the study, the most common injuries were a contusion of the knee in children, a sprain of the ulnar collateral ligament of the thumb in adolescents, and a grade-III sprain of the anterior cruciate ligament in adults. The short-term trends revealed that, in children, the frequency of tibial fractures decreased 10 per cent while that of fractures of the upper extremity increased 8 per cent. The long-term trends showed that, in adults, the rate of tibial fractures decreased 89 per cent while that of injuries of the anterior cruciate ligament increased 280 per cent. The overall rate of injury decreased 43 per cent from the beginning of the study in 1972 to the end of the study in 1994; the decrease was 58 per cent in children, 45 per cent in adolescents, and 42 per cent in adults. Data on the types of equipment and the binding-release values were collected prospectively from injured skiers and from 2083 non-injured skiers. Of the fifty-nine skiers who sustained a spiral fracture of the tibia, forty-two (71 per cent) had binding-release values that were higher than the average for the uninjured group. We believe that the use of properly functioning modern equipment will decrease the rate of injury, particularly in children.<br />