Joint pain can result from many issues, but the most common cause is arthritis. The most common form of arthritis is osteoarthritis. Pain in the knees due to arthritis may begin gradually and get worse with movement. You may also notice swelling and experience stiffness in the morning or after sitting for prolonged periods. Knee pain may also be cause by inflammation of the bursa (called bursitis). Bursae are gelatinous sacs in the joint containing some fluid. They reduce friction between muscle and bones by acting as a cushion.
Bursitis isn’t isolated to the knees; it can also cause pain in the shoulders and hips. Shoulder pain, which is often felt directly at the joints, can also be caused by osteoarthritis and damage to the rotator cuff or tendons.
The trunk of your body includes the hips and pelvis. Together, they are known as the “pelvic girdle”. The part of your hip that points out is known as the greater trochanter. This is the region where the muscles that move the hip joint attach. This region is also covered by a large bursa that can become irritated. The result is hip bursitis (trochanteric bursitis).
Like any other form of joint pain, a common cause of hip pain is arthritis, which usually manifests as pain in the groin and front of the thigh.