At fitness centers lately, a craze for the stepmill, which involves continuously climbing stairs, has continued. As word has spread that it burns many calories in a short time and can even have a hip-lifting effect, use among younger people has risen sharply. However, patients are also emerging who report pain at the front of the knee after excessive stair climbing.

Sports medicine experts point out that blindly repeating only the ‘going up’ movement can actually place a burden on the cartilage behind the patella. They explain that repeatedly loading body weight with the knee deeply bent carries a risk of causing patellofemoral pain syndrome (Patellofemoral Pain Syndrome). Cha Min-seok, director of Sejong Sports Orthopedic Clinic, said, "Recently, more patients have been complaining of pain at the front of the knee after excessively repeating stepmill or stair-climbing exercises," and added, "For the knee joint, how it receives load is far more important than simply using it a lot."

The situation is similar in hiking. In fact, many mountain accidents occur on the way down rather than on the way up. Recently, in sports medicine, research aiming to use the ‘descending motion’ as a therapeutic exercise has been attracting attention.

When coming down stairs or descending a slope, ‘eccentric contraction (Eccentric Contraction)’ occurs, in which muscles lengthen while resisting force. This is a different concept from a shortening contraction, in which muscles shorten to exert force, as in ordinary stair climbing. According to studies published in sports medicine journals worldwide, eccentric lower-body exercise has been reported to be effective in rebuilding tendons and muscles around the knee. In patients with patellofemoral pain, reductions in pain and recovery of function have been confirmed.

In a clinical trial on older adults conducted by a research team at Edith Cowan University in Australia, interesting results also emerged. One group performed stair-climbing exercise, while the other rode an elevator up and then performed only stair descents. After 12 weeks, analysis showed that the ‘descent group’ had decreased insulin resistance and improved LDL cholesterol and triglyceride levels. The interpretation was that, while the cardiopulmonary burden was relatively low, sufficient stimulus was delivered to muscle and metabolic function. Dr. Cha explained, "Eccentric exercise places a relatively lower cardiopulmonary burden but can give a strong stimulus to muscles and tendons, making it highly useful even for middle-aged and older adults or patients with knee pain," adding, "However, the key is to maintain precise form so that the knee does not receive the impact directly."

Experts also emphasize the importance of a ‘safe descent’ posture. Instead of striking the ground hard with the heel first, let the forefoot make contact first, and lean the upper body slightly forward so the hip muscles help absorb the impact. It is also important to keep the toes and knees in a straight line so the knees do not collapse inward. The key is to build coordination among all the muscles used in descending.

Dr. Cha said, "In joint health, what matters is not simply the ability to push up strongly, but the deceleration ability to safely control the body's speed," and added, "If you have knee pain, rather than mindlessly repeating only going-up exercises, doing controlled descent exercises in parallel may be far more helpful for protecting the joints."