Knee problems keep surgeons busy. Around 80,000 knee operations are carried out by the NHS in the UK every year and a lot of them are triggered by overuse and repetitive movements. If you hurt your knee playing sport you can probably afford time off for recovery but if your livelihood depends on being able to kneel you are in trouble. Electricians, plumbers, decorators and carpet fitters probably spent more time kneeling than standing some days. The obvious risk is kneeling on something hard and sharp, a fragment of concrete or metal or an uneven surface with raised edges. The less obvious risk is prolonged pressure which can interfere with blood circulation and can cause bursitis; a painful inflammation that accounts for 20% of the compensation claims in knee overuse injuries.
As an osteopath I see quite a few “dodgy knees”. Once the damage is done I can help reduce the pain but I can’t restore your knee once arthritis has permanently changed its shape. My advice is to protect your knees by using good quality knee pads while you are working.