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You should stop doing exercises untill assessed properly

If MRI shows no tissue or joint damage, exercise can be continued, but initiated under the guidance of a physiotherapist

This needs to be assessed properly, there are other reasons for knee effusion as well. Consult online or in person with the physical therapist for proper assessment and treatment.

Hey there! The reason behind your joint effusion should be known. The synovium has got irritated and inflamed which has resulted into escape of fluid/pus/blood into the recess. If you will do core leg exercises without first treating the cause of inflammation, it will prove no good. It will rather increase your problem. Please get consulted for better diagnosis.

you need to get a proper assessment and proper rehab exercise with gudance

you need a proper assessment and treatment from nearby physio or osteopathy

Hi First treat the joint effusion n then go with core leg exercises

If it is a right leg pain along the front of the knee cap pain, hamstring release could help. If you mean planks by core exercises, knee extension needs to be pain free, then it could help. If you mean abdominal exercises by lying on the back they should be fine. But you need to see a physiotherapist to assess and then see your ability to do these.

Hi. You need an online consultation for best diagnosis and treatment.