Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area of cells and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, cellular adhesion, and mechanotransduction. 1 Locations.
When youâre experiencing back knee pain, the cause of the problem may be due to a condition known as a Bakerâs cyst. When the back knee pain is associated with a Bakerâs cyst, it isnât a cyst in the usual sense. Itâs a popliteal cyst. What this means is that fluid is present in the joint at the back of the knee.
knee-pain. 1  Nerve impingement at L5-S1 can cause pain in the knees, although a clinical exam is needed to make an accurate diagnosis. Other causes of referred knee pain are injury to the hip joint and damage to the ligaments and meniscus at the knee joint. Joint fusion may alleviate your symptoms.