CORVALLIS - One of the best winter skiing seasons in recent history is drawing thousands of Oregonians to the snow-covered slopes of the Cascade Mountains this year, which has resort operators ringing cash registers and physical therapists tending to injuries.
Alpine skiing is a high-risk sport, experts say, and the knee is one of the more vulnerable areas.
The gravitational and centrifugal forces generated in creating a turn expose knees to injury, especially ligament damage and patellar problems, says Patrick O'Shea, a professor emeritus of exercise and sport science at Oregon State University and author of a ski fitness guide published by the National Ski Patrol System.
"The knee is one of the most complicated joints in the body," O'Shea said. "Knee injuries have the potential to end a skiing career, so it's not wise to subject knees to the stresses of skiing without first taking some protective measures to strengthen the supporting muscles and connective tissue."
O'Shea said strengthening the connective tissue - made of tendons and ligaments - will increase the amount of energy it can absorb before injury. Skiing on "weight-trained knees" extends the skier's safety margin.
The most common knee injury, he pointed out, involves the ligaments - those tough, fibrous bands that are attached near the ends of the bone as they meet to form the joint. Their main function is to provide joint stability by holding the bones together when the joint moves. Sprains occur when some of the fibers of the ligaments are torn.
Ligament strains are common in skiing and result when a force is exerted that exceeds the normal range of motion for the joint.
"This typically happens when someone is skiing too fast over uneven terrain, or making turns which cause excessive rotation of the knee," O'Shea said.
Most knee sprains are minor and can be treated with RICE - rest, ice, compression and elevation, O'Shea said. Ice applied immediately helps control swelling, but it shouldn't be applied directly to the skin. He recommends a treatment cycle of 30 minutes icing, followed by 15 minutes rest, repeated three times.
If pain and swelling last longer than 24 hours, O'Shea said, medical treatment is advised.
"The diagnosis and management of severe ligament injuries may require the expertise of an orthopedist sports medicine physician," he said.
Severe ligament injuries may include tearing of the deep medial ligament, the anterior cruciate ligament, or the medial meniscus. In those cases, surgery may be required to repair damage.
"Fortunately, the vast majority of knee injuries in skiing are not serious," O'Shea said. "It is the chronic 'skier's knee' that comes and goes that is frustrating. Mild pain and inflammation can often ruin an otherwise rewarding day of skiing.
"Injury prevention is the key."
O'Shea said a comprehensive strength training prescription for the knee can help prevent many injuries. A variety of exercises designed to maximize the body's "power zone" - which includes the hips, quadriceps and lower back - can provide much of the needed support.
Parallel squats are, perhaps, the best exercise, O'Shea said. But, he cautioned, "partial squats" are a poor substitute because the joints are worked through the full range of motion and may lead to over-development of the quadriceps at the expense of the hamstrings.
"Optimally, the hamstrings should be 80 percent as strong as the quadriceps," O'Shea said. "For a majority of recreational skiers, the ratio is 60 percent or less."
Other exercises that help develop strong, stable knees are leg and hip presses, knee extensions, leg curls, skier's squats and squat lunges.
If you're not 100 percent sure on how to do those exercises, consult with a fitness trainer, O'Shea emphasized.
"If you haven't lifted weights before, a two-day-a-week program - say Monday and Thursday - is a recommended regimen," O'Shea said. "Concentrate on mastering correct lifting techniques before using too much weight, especially in the parallel squat."
O'Shea suggests alternating workouts to do three of the exercises one day, and three others in the next workout to avoid overtraining. Follow the "8-12" rule, he added.
"If you can't do at least eight repetitions, the weight is too heavy," O'Shea pointed out. "And if you can do more than 12, the weight is too light." One exception: skier's squats, which can be done without weights until your legs "feel like gelatin."
In just a couple of weeks, you'll notice a difference, O'Shea said, and in six weeks, you can develop powerful legs for skiing, giving you greater edge control and a softer touch with the snow.
And with bases of several feet of snow in the mountains, it looks like good skiing through the spring.