This is a condition whereby there is an imbalance in muscular strength in the quadriceps (at the front of the thigh), which causes the knee cap to either rotate or shift sideways. Symptoms can include a grinding sensation beneath the knee cap as well as pain, particularly when walking up and down stairs.
IT Band Syndrome
IT band syndrome is an overuse injury that is common in endurance athletes like runners and bikers. It affects a tissue that runs from the side of your hip all of the way down past your knee. Most of the time, the inflammation manifests itself as pain on the outside of the knee. Common complaints can include some or all of the following: an aching, burning, or tenderness on the outside of the knee, feeling a click, pop, or snap on the outside of your knee, pain up and down your leg and warmth and redness on the outside of your knee.
A tendon is what attaches muscle to bone, tendinopathy simply means inflammation or degeneration of the tendon. Tendinosis is generally an overuse injury and a lot of the time people cannot recall what the onset of the pain was. When this occurs you may find the area feels stiff (particularly in the mornings), there may also be a considerable amount of pain which is commonly reported as an intense ache.