Activities associated with an Oriental lifestyle such as squatting during daily activities and the Lotus position have been considered potential risk factors for medial meniscal tears of the knee. In assuming the Lotus position, the feet are placed on the opposing thighs. It is a posture commonly used for meditation in the Hindu Yoga and Buddhist traditions. The position is said to resemble a lotus flower to encourage proper meditative breathing.
In this study, orthopedic surgeons examined 476 patients who had an arthroscopic exam for meniscal tears and analyzed whether a posterior root tear might be linked to these two positions.
The posterior root of the medial meniscus sounds like a mouthful but it really just describes the back corner of the meniscus. And specifically on the side of the knee closest to the other knee. This type of meniscal tear results in a piece of cartilage that is separated into two pieces but only attached to the bone (tibia) at one end.
Because of its location, the stress placed on this part of the meniscus could conceivably be greatest when the knee is in the extreme positions of flexion required in the squatting position. The same goes for the flexion and rotation required by the Lotus position.
But as it turns out, when they compared patients with medial meniscus posterior root tears (MMPRTs) with patients who had other types of meniscal tears, these two positions did not increase the risk for MMPRTs.
Of course, the researchers didn’t just look at positions when checking for potential risk factors. They collected a wide range of data including patient age, sex, body mass index (BMI), findings on X-rays, activity level, occupation, previous injuries, and use of a bed or table.
What they found was that it’s mostly intrinsic factors (not lifestyle) that make a difference. The four intrinsic risk factors with the greatest impact on MMPRTs included: increased age (older than 50 years of age), female sex, being overweight (higher BMI), and lower level of sports activity. The mechanical angle of the knee (as seen on X-rays) was one anatomic feature that also increased the risk of MMPRTs.
This study brought to our attention the importance of these risk factors. In the bigger picture, these risks are important because we know that meniscal tears can leave a person at risk for early knee osteoarthritis. Knowing what the risk factors are for the tears might help us find better ways to prevent these injuries in the first place. And that would mean reducing the risk of early degenerative knee osteoarthritis. It’s a double win-win situation.
The fact that positions often used by Oriental people did not contribute to the posterior corner tears of the medial meniscus may be because the knee structure adapt to these positions when used from an early age on. We do not know if this type of injury occurs more often in those individuals who begin using these positions later in life.