I swim and play tennis and soccer three times a week but since last week, I've had pain in my knee. A friend says this probably a muscle-tendon injury. What should I do?

The muscle and tendons work together as units. Injuries can affect muscle belly, muscle-tendon junction, the tendon itself, and the insertion of the tendon to the bone. Muscles can be damaged both by direct trauma (impact) and by indirect trauma (overloading). Muscle injuries are usually benign but often annoying and inadequate treatment can result in a long absence from any sporting activity. Strain is caused by over-stretching of muscles or tendons. Contusions occur as result of direct impact, such as when a player's knee hits another's thigh during a soccer game. When injuries occur, there is inevitably some degree of bleeding followed by pain and then the inflammatory process. A sharp or stabbing pain is felt when the injured muscle-tendon contract. Usually there is little pain providing the muscle is rested. After 24 hours, bruising and discoloration may be seen (a sign of bleeding in the injured muscles).

The initial treatment is rest, bandaging the injured part, cooling the affected area with ice, elevating the limb and relieving the load on the injured part. This should be done within the first 24 to 72 hours. Muscle exercises should only commence after at least two but preferably five days of rest.

Dr Pak Thongpak is an Orthopaedic Surgeon at BNH Hospital