<prompt> A healthy young athlete sitting at table with knee at 90deg flexion. What will happen when he fully extends the knee?Movement of tibial tuberosity towards medial border of patellaMovement of tibial tuberosity towards lateral border of patellaMovement of tibial tuberosity towards centre of patellaNo change in relationship  <response>: In sitting posture when foot is off the ground, full extension leads to knee locking by lateral rotation of tibia. Hence, tibial tuberosity moves laterally towards the lateral border of patella. 