What a muscle contusion is
A contusion is an injury caused by a direct blow. Muscle fibres and small blood vessels are crushed, and blood collects in the muscle, forming a haematoma. This causes pain, swelling and bruising. It differs from a muscle strain, which is caused by overstretching or overloading.
See muscle tear and quadriceps strain.
Symptoms
- Pain at the site of the blow.
- Swelling and bruising, which may spread downwards.
- Tenderness and a firm area in the muscle.
- Stiffness and reduced movement.
- Weakness and a limp if the leg is affected.
Thigh contusion (dead leg)
The front and outer thigh are commonly hit in football, rugby and martial arts. Testing how far the knee bends 24 hours later helps grade the injury: more than 90 degrees is mild, 45 to 90 degrees moderate and less than 45 degrees severe.
Knee contusion
A blow to the knee can bruise the muscles around it, the kneecap or the bone itself (bone bruise). It causes pain, swelling and difficulty kneeling. Bone bruises can take several weeks to settle. Persistent swelling inside the joint should be checked.
See joint effusion and ice or heat for knee pain.
First aid
- Stop the activity.
- Apply ice wrapped in a cloth for 15 to 20 minutes every 2 to 3 hours for the first 48 hours.
- Use a compression bandage.
- Raise the limb.
- For a thigh contusion, keep the knee gently bent if comfortable.
- Use crutches if walking is painful.
What to avoid in the first 72 hours
- Heat: hot baths, saunas and heat packs.
- Alcohol: increases bleeding and swelling.
- Running: can worsen damage.
- Massage: may increase bleeding.
- Aggressive stretching.
Rehabilitation
- Days 1 to 3: gentle movement within comfort.
- Days 3 to 7: gentle stretching and light strengthening.
- Week 2 onwards: progressive strengthening, cycling and jogging.
- Return to sport: when movement and strength are near normal.
See quad stretches and hamstring stretches.
Recovery time
- Mild: about 1 to 2 weeks.
- Moderate: about 2 to 4 weeks.
- Severe: 4 weeks or more.
Myositis ossificans
After a significant contusion, bone can occasionally form within the muscle, causing a hard, painful lump and reduced movement that persists after 2 to 3 weeks. It is more likely after severe injuries, repeated blows or early massage. An X-ray or ultrasound confirms it, and most cases settle with time and careful rehabilitation.
Compartment syndrome
Rarely, bleeding and swelling within a tight muscle compartment raise the pressure enough to cut off circulation. This causes severe pain out of proportion to the injury, tense swelling, pain on stretching the muscle, numbness and weakness. It is a surgical emergency.
Prevention
- Wear protective padding in contact sports.
- Use correct tackling and falling techniques.
- Allow full recovery before returning to sport.
Bruising that is not from an injury
Frequent or unexplained bruising, large bruises from minor knocks or bruising with bleeding gums or nosebleeds can indicate a blood clotting problem or medication effect and should be checked by a doctor.
Contusions in children and older adults
Children often bruise from play and usually recover quickly. Older adults and people taking blood thinners may develop larger haematomas after minor knocks and should seek advice if swelling is large or keeps growing. A large bruise after a fall in an older person may hide a fracture.
When to seek urgent help
- Severe pain that keeps increasing.
- Tense, hard swelling.
- Numbness, tingling or a cold, pale limb.
- Inability to bear weight or move the joint.
- A hard lump that persists after 2 to 3 weeks.
Key points to remember
- A muscle contusion is a bruise inside the muscle from a direct blow.
- Ice, compression, elevation and early gentle movement help.
- Avoid heat, alcohol and massage in the first 72 hours.
- Severe or increasing pain needs urgent assessment.
Questions about muscle contusions
These answers are general information and do not replace an examination or individual medical advice.
How long does a bruised muscle take to heal?
Mild contusions take 1 to 2 weeks; severe ones longer.
Should I massage a bruised muscle?
Not in the first 72 hours, as it may increase bleeding.
Is heat or ice better for a muscle contusion?
Ice in the first 48 hours; gentle heat later.
What is a dead leg?
A thigh muscle contusion from a direct blow.
Can I walk on a bruised thigh?
Yes, within comfort; use crutches if walking is painful.
What is the difference between a contusion and a strain?
A contusion is from a blow; a strain from overstretching.
Why is there a hard lump in my bruised muscle?
It may be a haematoma or, rarely, myositis ossificans; get it checked if it persists.
How long does a knee contusion last?
Usually 1 to 3 weeks; bone bruises can take longer.
When can I return to sport?
When movement and strength are near normal and pain-free.
Sources
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.