Hi. Crackling sound in your knees, with pain in Anterior aspect of knee is common in sitting job professionals. This is due to weakness of your quadriceps muscles as a result your knee cap hits the femoral surface and cause softening of the cartilage which is called chondromalacia which in turn leads to sounds and pain.
Next Steps
Treatment very simple. Strengthening quadriceps and hamstring. Don't sit for a long time at one place more than 30-40 min. Cycling 30 min per day. No knee cap to be applied it will weaken your muscles more
Health Tips
Regards
Dr Sachin Jain
Arthroscopic surgeon and Sports medicine expert, Jaipur
Team India doctor for commonwealth games 2018