If you do experience some pain or discomfort while performing an activity, you need to stop doing that activity. The step is to check your technique. Often injuries are due to improper technique. This is especially true with weightlifting machines and exercises. Ask a certified strength and conditioning specialist or a certified personal trainer to help you make sure you have proper technique.
Proper technique is important for even simple activities such as walking.
If you have improper technique, you may be at risk for developing a repetitive motion injury. This is where improper form may produce minor strain on a muscle or tendon or ligament. This is not a serious problem. However, when this activity is repeated many times, the trauma to the area increases and can lead to more serious problems, such as including tendonitis or shin splints. Once you have proper technique, you should no longer experience any pain or discomfort.