Clinically, an avulsion fracture of the ischial tuberosity may occur. Quadratus arises on the ischial tuberosity and is inserted into the intertrochanteric crest. The patellar ligament connects the patella to the tuberosity of the tibia. Tibial tuberosity fractures are infrequent fractures, most common in adolescents. Tenderness in the tibial tuberosity can arise from Osgood-Schlatter disease or deep infrapatellar bursitis. Additionally, lesser tuberosity bony changes have been associated with subscapularis tendon tears. When sitting, the weight is frequently placed upon the ischial tuberosity. The main portion of the muscle inserts into the tuberosity of the navicular bone. Semimembranosus&colon; originates on the ischiatic tuberosity and inserts on the femur and tibia. When sitting, the weight is frequently placed upon the "ischial tuberosity". It can be fractured along with the tibial tuberosity. The radius has two, the radial tuberosity and Lister's tubercle. The brevis is attached on the lateral side to the tuberosity of the fifth metatarsal. This is located posteroinferior to the deltoid tuberosity. It is important that the examiner's thumb be on the tibial tuberosity.