Objective: Yoga is becoming more and more popular in the female society while the concomitant sports injury is seldom mentioned. Many clinicians have noted that yoga may result in knee problems, which though requires more researches to corroborate. This investigation was conducted to ascertain the relationship between yoga and meniscus injury as well as the extent of impairment according to variant yoga practice periods.
Methods: Totally 819 women aged 20-49 years who practiced yoga or other popular sports including badminton, jogging, climbing hills, etc for at least one hour per day were selected to participate in this research. These subjects were required to complete a questionnaire and receive relevant physical examination. Magnetic resonance (MR) scan of the knee was recommended for the suspicious subjects for ultimate diagnosis. The subject with abnormal meniscus MR signals was defined as a case and matched with two controls in terms of age and body mass index (BMI). Altogether there were 273 cases and 546 controls. The nested case-control model was adopted to assess the risk of meniscus injury between variant exposures in practicing yoga and several other popular sports. Moreover, the 181 yoga subjects were subdivided into three groups according to different exercise durations, followed by further analysis with the variables of age, BMI and Lysholm score.
Results: Yoga was found associated with a higher risk (P equal to 0.008, OR equal to 1.621) of meniscus injury compared with badminton, jogging and climbing hills. The three yoga subgroups showed statistical difference between each other in terms of Lysholm score (P equal to 0.027) and BMI (P equal to 0.003). The subjects with longer-term yoga practice had lighter weight but lower Lysholm scores.
Conclusions: Yoga perhaps exerts destructive impact on the meniscus for Chinese women, yet it needs further verifications. Furthermore, the female yoga players with longer exercise duration are more susceptible to meniscus injury though they can become leaner.