Is there anything (ie. passive movement or walking) that increases the production of synovial fluid?

The cyclic compression and release of the articular cartilage during walking certainly helps in maintaining continuous circulation of synovial fluid into and out of cartilage. Compression from weight bearing squeezes fluid out of the cartilage and into the synovial cavity and fresh fluid enters the cartilage from that cavity when the weight is released. Cyclic exchanges of healthy synovial fluid are among the benefits of exercise.

It is certainly possible that the increase in systemic blood flow that occurs during exercise increases blood flow to the synovial membranes and thus the rate of exchange of fluid between the joint cavity and the associated capillary beds, delivering fresh nutrients and oxygen to the fluid bathing the articular cartilage and removing CO2 and wastes. Whether increased blood flow would cause an actual increase in synovial volume or just make for healthier maintenance of a steady state amount and composition of synovial fluid is not clear to me.

Joint inflammation is a known cause of increased synovial fluid volume, but because it mainly involves more fluid (plasma ultrafiltrate), the concentration of key lubricating elements of the synovial fluid (e.g., glycosaminoglycans) often decreases and the protective function of the fluid may thus be compromised. Because of this, simple increases in volume are not necessarily beneficial.

Thanks for the question!

Dr. Douglas Paulsen