The symptoms of carpal bossing may develop due to underlying conditions such as bursitis, osteoarthritis and damage to the tendons. Although most people are unaware of what causes carpal bossing, medical practitioners attribute the condition to repetitive wrist movements and traumatic injuries affecting the wrist.

The second and the third carpometacarpal joints are designed to have very little movement. Carpal bossing is commonly found in sports players who force this joint in extension and where there is repetitive movement in the wrist, such as with golf or racket sports. This is, therefore, commonly seen in tennis players where the bony prominences develop on both sides of the joint.   As these joints don’t have any cartilage, they tend to “kiss” each other when the wrist is in extension. This creates pain, which the body tries to heal by developing bony spurs, which form a bump on the back of the hand.