An injury will occur when a tissue is subjected to an irritation (over-load, pressure, blow etc.). All injuries release an acute inflammatory reaction that is crucial for the healing of the injury. The acute inflammation can develop into a chronic inflammation, which represents a serious complication, if the irritation (over-load) continues. The chronic inflammation acts by breaking down the tissue (causing a weakening of the tendons, cartilage, etc.) and results in pain which will necessitate a break in training involving further weakening of the muscles, tendons and bones. Chronic inflammation is often troublesome to treat, requires prolonged breaks in activity and can in worst cases result in injuries that make a resumption of sport an impossibility (sports disablement). Prevention of the outbreak of chronic inflammation is consequently vital for continued sports activity. This is primarily achieved by reacting to the signals from the body revealing that there is something not as it should be (i.e. tenderness and pain), removing the triggering load by adjusting training and seeking sports medicinal advice and guidance. It is naturally also important to start correct rehabilitation and treatment programs as quickly as possible.
The complaint is termed "inflammation", and the condition has no relation to “infection” and penicillin has consequently no effect whatsoever.