Down syndrome is one of the most common genetic disorders. According to the Centers for Disease Control and Prevention, it affects about 13 babies in every 10,000 births. Its primary effect is mental retardation and a number of physical abnormalities.

The child may have special medical problems of the heart, stomach, eyes and other parts of the body. Some problems in Down syndrome involve the bones and joints (musculoskeletal system).

A child with Down syndrome may have weak muscle tone (hypotonia). He or she may also have ligaments that are too loose (ligament laxity). This leads to excessive joint flexibility. Associated findings include:

• Developmental delays. A child with Down syndrome will eventually reach the same growth milestones as other children. But, he or she may be slow learning to turn over, sit, stand, walk or do other physical activities.
• Joint instability. Children with Down syndrome may have joints, such as the hip or knee, which slip out of place or become dislocated. Joint laxity in the neck may be excessive. This can lead to compression of the spinal cord.
• Other Problems. Down syndrome may also lead to other problems, such as flat feet and bunions.

Getting early medical care and treatment (intervention) can improve the health of a child with Down syndrome and address some musculoskeletal problems.

Because children grow most rapidly during the first three years of life, it is important that the child have a comprehensive medical examination at birth.

The doctor may recommend a special program of physical therapy, exercise, and other activities early on. Early intervention can help a child with Down syndrome achieve developmental skills and build muscle tone and coordination. It can also give extra stimulation and encouragement to help the child achieve his or her full potential in life. Many children with Down syndrome go on to hold jobs and live independently well into middle age and beyond.

Early diagnosis and treatment is also important for managing orthopaedic problems in children with Down syndrome. Some children may need splints or other devices for physical activity. Sometimes your doctor may refer you to a pediatric orthopaedist for specialized help or surgery.

In some people with Down syndrome, the upper part of the spine (cervical) is abnormal under the base of the skull. Muscles are weak and ligaments may be looser than they should be. Potentially, this can cause bones (vertebrae) in the neck to press on the spinal cord, leading to an inability to coordinate muscle movement and weakness.

Any progressive changes in a child with Down syndrome should be brought to the doctor's attention. These changes may include:

• Weakness, clumsiness and tripping
• Walking with stiff legs
• Having a stiff neck, neck pain, and headaches
• The doctor may recommend taking X-rays of your child's neck to look for joint laxity. In some cases, a child may be kept out of contact sports or other activities that put stress on the neck, such as high jumping, diving, gymnastics, and using a trampoline.

A child with Down syndrome should be encouraged to be physically active and consume a healthy diet. This will help them avoid excess weight gain and other physical problems. Your doctor can help develop a well-rounded exercise routine that includes aerobic activity, strength training, and stretching exercises.

Occasionally, a child with Down syndrome may need a type of surgery called spinal fusion to hold the bones in the neck together. This will prevent excessive pressure on the spinal cord.

Surgery may also occasionally be needed to manage looseness of the hip and knee joints and looseness of the joints in the feet.