Duchenne muscular dystrophy (DMD) is a genetic disease. It causes muscle weakness that worsens over time. Before age 5, the muscles in the legs, arms, and trunk begin to weaken. Later in the disease, the heart and muscles that help you breathe weaken.


DMD is caused by a problem with genes. The problem with the gene makes it hard to make a specific protein called dystrophin. This protein is needed to keep muscles healthy.

Risk Factors

DMD is more common in male children. A family history of DMD increases the risk of having the disease.


Symptoms of DMD may include:

  • Child is late in learning to walk
  • Larger than normal calf muscles
  • Frequent falls
  • Clumsy walking
  • Difficulty climbing stairs
  • Trouble running
  • Walking on toes or balls of feet
  • Trouble with balance
  • Walking with shoulders back and belly out
  • Trouble keeping up with friends when playing
  • Learning disabilities

Contracture of the Hand

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You will be asked about your child’s symptoms and past health. A physical exam will be done. You will be asked if there is any family history of muscle or nerve diseases. The exam will focus on your child’s muscles and signs of weakness. Your child will often be referred to a specialist.

DMD may be suspected based on symptoms and family history. It can be confirmed with:

  • Muscle biopsy
  • Blood tests—for genetic testing

Other tests may be needed to rule out other causes with similar symptoms.


Talk with your doctor about the best plan for your child. Your child will need different treatment and support as the disease progresses. Options include the following:

Physical Therapy

Therapy plays a large role in DMD. Your child will work with a therapist to try to keep muscles strong.

The disease also causes muscle shortening and tightening. It will make it difficult to move. The therapist will focus on preventing this with range of motion exercises.

Scoliosis is common in DMD. Exercises can help to keep the back as straight as possible.

Assistive Devices

Braces are used to keep the legs straight. They can also prevent tightening of joints like hands. A walker and wheelchair may be needed later when the leg muscles become too weak to walk.


Steroid medication, like prednisone, may be prescribed. This can help to improve muscle strength and slow muscle weakening.

Steroids can also weaken bones. Vitamin D and calcium supplements may be given to improve bone strength. If heart problems exist, medications may be given to slow the damage.

Respiratory Therapy

As the disease progresses, the muscles that support breathing may weaken. A ventilator may be needed. It will deliver air through a mask or tube. At later stages a hole may be made in the throat to place a trach tube.


Surgery is sometimes used to treat symptoms of DMD. It may help to release tight muscles or relieve curves in the back.


There are no known guidelines to prevent DMD.


Muscular Dystrophy Association

National Institute of Neurological Disorders and Stroke


Canadian Institutes of Health Research

Muscle Dystrophy Canada


Duchenne and Becker muscular dystrophies. EBSCO DynaMed Plus website. Available at: Updated October 30, 2017. Accessed December 27, 2018.

Duchenne muscular dystrophy. Muscular Dystrophy website. Available at: Updated February 9, 2017. Accessed December 27, 2018.

Last reviewed June 2018 by Laura Lei-Rivera, PT, DPT, GCS  Last Updated: 12/27/2018