Acute Sports Injuries - MUSCLE CONTUSION

Muscle contusion is the medical term for a muscle bruise, and refers to bleeding and subsequent haematoma formation within a muscle and its surrounding connective tissue sheaths. Contusions occur when a muscle is compressed against the underlying bone by a blunt, external force - resulting from a direct blow or collision with an external object e.g. another player or a piece of equipment. They are common in contact sports and those involving sticks and balls. The most common sites for a muscle contusion are the quadriceps, gastrocnemius and gluteal muscles, but muscle contusion can occur in any muscle exposed to a blunt compressive force.

Muscle compression causes muscle fibre damage and rupture of miscrovessels. The released blood clots to form a haematoma that initiates an acute inflammatory reaction aimed at removing the haematoma and damaged tissue and initiating a repair response. The haematoma may form either within (intramuscular) or between (intermuscular) the fascial coverings of the muscle.

Intramuscular contusions are more self-limiting as the rise in pressure within the confines of the fascial compartment reduces blood flow, but they are also generally more painful and restrictive because muscle contraction results in further rises in compartment pressure and stimulation of nocireceptors.

Intermuscular contusions are generally less painful as the fascial sheath is damaged, allowing the haematoma to spread and relieve compartment pressure. Intermuscular haematomas are generally more evident externally as the blood is able to travel distally due to gravity and into the subcutaneous tissues resulting in a visible bruise.

Initial management of a muscle contusion involves assessing for presence of an acute compartment syndrome, controlling bleeding to reduce secondary injury (e.g. muscle fibre hypoxia) and protecting the injured site from further injury. Techniques include compression and ice with the muscle placed in a pain-free stretched position to help stop the bleeding and reduce muscle spasm. Techniques such as heat, alcohol and vigorous massage, which have the potential to increase blood flow and/or cause a rebleed, should be avoided in the acute and subacute stages. Subsequent management focuses on restoring muscle function via progressive stretching and strengthening. The use of protective equipment in the form of force dissipating and dispersing padding should be considered to prevent re-injury upon return to activity. However, the reduction in injury risk gained by using protective equipment will need to be weighed against any associated reduction in athlete mobility and performance.

REFERENCES

Brukner, P., 2012. Brukner & Khan's clinical sports medicine. North Ryde: McGraw-Hill.