The most common cause of joint pain is arthritis and a common form of arthritis is osteoarthritis. Pain in the knees due to arthritis may begin gradually and get worse with movement. It may also cause swelling and stiffness in the mornings or after sitting for prolonged periods of time. Knee pain may also be caused by inflammation of the bursae (bursitis), which are gelatinous sacs in the joint containing some fluid and reduce friction between muscle and bones by acting as a cushion.
Shoulder pain, which is often felt directly at the joints, can also be caused by osteoarthritis, bursitis, and damage to the rotator cuff or tendons.
The trunk of your body includes the hips and pelvis, and together they are known as the “pelvic girdle.” The portion of your hips that points outward is known as the greater trochanter. This region is where the muscles that move the hip joints attach and is also covered by a large bursa that can become irritated. This results in hip bursitis (trochanteric bursitis). Hip pain, like any other joint, can also be caused by arthritis, which usually manifests itself as pain in the groin and front of the thigh.