How will I know if my meniscus is torn in my knee ?

Meniscus injuries in a knee are not constantly painful and will only cause pain after activity involving twistng or jarring of the knee for instance after a run or a hike on uneven ground. The knee will be painful if you kneel on it and mat get swollen from time to time. The best way to know is to have an examination by an experienced Orthopaedic surgeon and a MRI scan may be required.