Muscles can be damaged by direct trauma (impact) or by overloading. The damage to the muscle can be divided into one of two categories, either a rupture or haemotoma.

RUPTURES

A Distraction Rupture is caused by over-stretching or overload and usually happens on the surface of muscle or at the origin or insertion. A Compression Rupture is caused by a blow to the muscle. In both cases some of the muscle fibres are torn. Ruptures are classed according to severity:

1. A First Degree Strain (Mild Strain-Partial Rupture)
Less than 5% of fibres are torn. No great loss of strength or movement. Movement will cause pain in area of damage.

2. A Second Degree Strain (Moderate Strain-Partial Rupture)
More than 5% of fibres are torn but not all. Movement causes pain.

3. A Third Degree Strain (Severe Strain-Total Rupture)
All fibres are torn. Very painful. Loss strength and mobility. Muscle usually cannot contract.

Symptoms and Diagnosis.

• Instant pain at moment of injury.
• Pain in partial rupture can inhibit contraction. Total rupture allows no contraction.
• Partial rupture may produce a small lump in area of tear. Total rupture often results in defect being felt across entire muscle belly.
• There is localised swelling and tenderness.
• After 24 hour period there may be bruising and discoloration, indicating bleeding within damaged muscle.

Healing
The repair of muscle involves the formation of new muscle fibres (regeneration) and production of scar tissue (granulation).

HAEMATOMA

Intramuscular haematoma involves bleeding within the muscle sheath (fascia). Usually severe swelling is evident when a muscle sheath and adjacent blood vessels are damaged. Usually there is a large area of bruising visible.

Treatment of muscle rupture and haematoma
The athlete should control bleeding by:

• Resting
• Cooling injured area
• Bandaging part
• Elevating limb
• Removing loads from limb (e.g. using crutches)