One hundred tennis players were recruited from the professional men's tennis tour to investigate the correlation between hip internal rotation deficits and low back pain (LBP), as well as shoulder internal rotation deficits and shoulder pain. A statistically significant correlation was observed between dominant shoulder internal rotation deficits and shoulder pain. Also observed was a statistically significant correlation between lead hip internal rotation deficits and lumbar extension deficits with LBP. We conclude that due to repetitive demands on the dominant shoulder and repetitive pivoting at the lead hip, the cycle of microtrauma and scar formation leads to capsular contracture and subsequent reduction in internal range of motion. It is likely that the limitation in lumbar extension in the symptomatic group is not only due to decreased flexibility from an increased load on the spine, but also due to a protective mechanism to prevent further exacerbation of the LBP. Physical conditioning that includes shoulder as well as hip internal rotation stretching programs should therefore be essential aspects in the treatment of tennis players with shoulder pain and LBP respectively.