The most common cause of tennis elbow is doing activities where you’re repeatedly and forcefully gripping and twisting your wrist. For example, you're more likely to develop the condition if you’re a plumber, bricklayer, painter, decorator or gardener. Carrying heavy loads can also cause tennis elbow. If you spend more than 20 hours at a computer each week (especially for many years), you’re also more likely to get tennis elbow. This is because these activities can cause minute tears in your arm muscles and tendons and inflammation.