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from the American Academy of Orthopaedic Surgeons

Diseases & Conditions



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Cerebral Palsy

Cerebral palsy (CP) is a disorder that affects a child's ability to control their muscles. It is caused by damage or abnormalities in the parts of the brain that are involved with movement and coordination. The spinal cord and muscles in a child with CP are structurally normal.

In most cases, cerebral palsy begins before a baby is born; however, CP can also begin at birth or during the first years of life. Early signs of CP include delays in meeting milestones, such as learning to roll over, sit, crawl, or walk.

Although there is no cure for CP, the disorder does not worsen as a child grows. Sometimes, as a child gets bigger, the muscles need to work harder, and the child may seem to have worse function. Early treatment, such as physical therapy, medication, braces, and other assistive devices, can significantly help children improve their functional capabilities. 


There are many conditions and problems that may lead to the development of CP:

  • Before birth, the brain of the unborn child is sensitive to damage from maternal infections and toxins, as well as exposure to drugs and alcohol. These factors may contribute to the development of CP.
  • Lack of oxygen during birth has also been linked to the development of CP.
  • After birth, infection (especially in low birth weight babies), lack of oxygen and head injury may be contributing factors.
  • Premature babies are also at a greater risk for CP. 

In most children with CP, however, it cannot be determined how the problems in the brain occur.


Cerebral palsy affects approximately 2 out of every 1,000 live births.

The physical disabilities associated with CP can be mild, moderate, or severe, depending on which part and how much of the brain are involved.

Some children can walk independently, while others need assistive devices, like crutches or walkers. Some children with CP require the use of wheelchairs for mobility. 

Young girl with cerebral palsy

(Left) When this young child with CP walks, she must use her arms to maintain balance. (Right) Using a walker helps the child improve balance and stability.

Reproduced from Sussman MD: The orthopaedic management of cerebral palsy. Orthopaedic Knowledge Online Journal 2009; 7(4). Accessed January 2018. 

Classification of Cerebral Palsy

Doctors typically describe CP using three major classification systems. These are:

  • Physiologic
  • Geographic
  • Functional


There are four main types of cerebral palsy in the physiologic classification. Doctors can usually diagnose the specific type of CP when a child is about two years old.

  • Spastic. The most common form of cerebral palsy is spastic CP, in which a child has increased muscle tone/tightness. A child's legs, arms, and back are stiff and contracted, which makes movement difficult.
  • Athetoid. A child with athetoid CP has low muscle tone/looseness, which makes limbs weak and floppy. Athetoid CP causes uncontrolled and involuntary movements of the entire body. It may be difficult for a child to sit up straight or walk and speech can often be difficult to understand.
  • Ataxic. This rare form of CP affects balance and depth perception. There is poor coordination, with a wide-based and clumsy gait. There is also difficulty with precise movements, such as using a pen or buttoning a shirt.
  • Mixed. In mixed CP, there are symptoms of both spastic and athetoid CP. Some muscles are tight and others are loose. There is both stiffness and involuntary movements.


Cerebral palsy can also be classified by the part of the body affected and how severe the effects are.

  • Diplegic. Both legs are affected. Tight muscles in the hips and legs often cause the legs to turn inward and cross at the knees when walking, called "scissoring."
  • Hemiplegic. One side of the body is affected. The arm is often more severely affected than the leg.
  • Triplegic. Both legs and one arm are affected
  • Quadriplegic or total body involvement. All four limbs and the trunk are affected. Independent walking may be difficult, or even not possible. In addition, the muscles of the mouth and tongue also may be affected, making swallowing and eating difficult.


The Gross Motor Functional Classification System (GMFCS) is most commonly used to describe how independently a child with CP is able to function. The GMFCS level will also help your child's doctor make recommendations on monitoring for hips coming out of the socket and developing curves in the spine (neuromuscular scoliosis).

There are five functional levels:

  • I.   Able to walk without restrictions and is able to keep up with their peers.
  • II.  Able to walk indoors and outdoors but is often unable to keep up with peers and will sometimes require leg braces.
  • III.  Uses walking aids, such as crutches or a walker, for shorter distances and may use a wheelchair when traveling for long distances.
  • IV.   Able to propel own wheelchair, usually non-ambulatory.
  • V.   Unable to be independently mobile and support trunk.

Other Impairments Associated with CP

In addition to affecting muscles and motor skills, CP may cause a range of other impairments in some children. These include:

Doctor Examination

Medical History and Physical Examination

Give the doctor your child's complete medical history. This may help to rule out other disorders that can cause movement problems, such as genetic or muscle diseases, metabolism disorders, and tumors of the nervous system.

Your child's doctor will evaluate your child's muscle tone and reflexes, and may want to watch your child walk, crawl, sit, and lie down.

If your child is less than 1 year old, the doctor may need to wait a few months before confirming the diagnosis of cerebral palsy to see whether your child develops specific problems with movement or is not meeting developmental targets like sitting up and walking.

During the physical examination, the doctor also may check for other conditions linked to CP, such as mental impairment, seizures, and vision problems. 


There is no specific blood test or imaging study that can make the diagnosis of cerebral palsy.

However, your child's doctor may order a magnetic resonance imaging (MRI) scan of your child's brain. This test can show damage or abnormalities in the brain. 


Individuals who have cerebral palsy often need help from their families and medical specialists throughout their lives. Many types of healthcare professionals are involved in treating those with CP.

Depending upon the type of CP your child has, as well as any additional impairments, the medical treatment team may include:

  • Orthopaedic surgeons to treat problems with bones, muscles, tendons, nerves, or joints
  • Physical therapists to improve movement and strength
  • Occupational therapists to teach daily living skills, such as eating and dressing
  • Speech and language specialists to treat communication problems
  • Social workers to help locate community assistance and education programs
  • Psychologists to help patients and families cope with stress
  • Behavioral therapists to foster social and emotional development
  • Other medical specialists such as eye doctors, neurologists, and nutritionists

Nonsurgical Treatment

Physical therapy. Physical therapy may be recommended shortly after the diagnosis is made to help your child learn skills such as sitting, walking, or using a wheelchair. It also may help improve muscle strength, balance, and coordination, as well as prevent muscles from becoming too tight. Physical therapy may involve fun activities to tone muscles, like swimming and horseback riding. 

Physical therapy for patients with cerebral palsy
(Left) A physical therapist teaches a child with CP to use walking sticks. (Right) A young child with CP learns how to use a harness walker.

Reproduced from Sussman MD: The orthopaedic management of cerebral palsy. Orthopaedic Knowledge Online Journal 2009; 7(4). Accessed January 2018. 

Braces, splints, and casts. Using braces, splints, or casts may improve range of motion in joints and joint stability, prevent contracture, and improve hand or leg function. Braces can compensate for muscle imbalance.

Botox. This drug can be injected into spastic muscles to loosen them. It is especially helpful for children younger than 5 years old, and when used in combination with casting.

Medication. Some medications (such as oral diazepam and baclofen) can control or prevent seizures or muscle spasms, ease muscle stiffness, or reduce abnormal movements. 

Surgical Treatment

If contractures are severe, surgery to lengthen affected muscles can improve a child's ability to move and walk. This surgery may also help if tightly contracted muscles cause stress to joints and lead to deformities or dislocations.

Some children with CP need surgery to correctly position their arms or legs, or to correct curvature of the spine (neuromuscular scoliosis).

Severe spasticity and muscle stiffness may be helped with an intrathecal baclofen pump. In this procedure, a small pump is surgically implanted under the skin to deliver doses of a muscle relaxant.

If other treatments cannot effectively manage severe spasticity, your child's doctor may recommend selective dorsal rhizotomy. During this surgery of the spine, the surgeon cuts specific nerves that control spastic muscles. This helps the muscles relax, as well as to relieve associated pain. This particular type of surgery is rarely performed. 

Coping Strategies

Parents of children with cerebral palsy or other disabilities often feel guilt and/or grief about their child's condition. Some tips to help parents cope:

  • Learn all you can about CP. You may want to join a family support group or get help from professionals. Stay informed about new treatments and technologies. Organizations like the American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) and Cerebral Palsy Alliance Research Foundation (CPARF) can be good places to start.
  • Work with professionals at your child's school to develop an individualized plan that meets their needs and abilities.
  • Love and encourage your child. Family support and personal determination are important factors in achieving long-term goals. Go places and have fun. 
  • Get help from family and friends. Caring for a child with CP is hard work. Teach others how to do it so you can take breaks. 

Learn more about pediatric musculoskeletal conditions and injuries at POSNA's OrthoKids website.

Last Reviewed

April 2022

AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.