Joint fluid fills the small space between the ends of bones and acts like a natural lubricant. The synovial membrane creates this thick, silky fluid using long molecules that hold water and give it a Diagram of the presence of lubricin in the SF of the healthy knee joint Download Scientific Diagram Home Remedies for Knee Pain: Causes, Relief & When to See a Doctor Max Hospital Can Exercise Make Knee Arthritis Pain Better or Worse? Total Ortho Sports Medicine