Unexplained limping in a child should be evaluated quickly. Some simple causes may include a small rock in the child’s shoe, a splinter in a toe, or a twisted ankle. If no source of limping is obvious after a quick look at the child’s shoes, feet, ankles and legs, the child should see a doctor. Limping may indicate a problem that will result in permanent disability if not treated. Limping with pain may indicate an injury or an infection. Limping with fever may represent an infection in the bone or joints. New, unexplained limping without pain may also be a urgent problem, such as Legg-Calvé-Perthes disease (lack of blood supply to the hip joint) or a slipped capital femoral head (a dislodgement of the top of the leg bone in the hip). Both of these problems can lead to permanent disability if not treated quickly.
What is a limp?
Limping is a disruption of the normal gait (or the way your child walks). Children first learn to cruise (walk holding onto something) at about 10 months of age and learn to walk freely around 12 months of age. As children are learning to walk they normally stumble, fall, and make jerky steps. This improves over several months and most children will have a normal (adult-like) gait by 3 years of age. Limping occurs when stepping with one foot is faster, slower or more jerky than a step with the other foot. This can occur when putting weight on the foot causes pain.
What if my child always had a limp?
This may be due to problems your child was born with such as…
Leg length discrepancy – Some children are born with one leg that is longer than the other. This may not be noticed until around 3 years of age when your child has an adult-like gait. Sometimes shoe inserts or special shoes can correct the difference. Surgery is reserved for severe cases.
Cerebral palsy – This is a neuromuscular disease that some children are born with. Often the cause of cerebral palsy is not known, but children who suffer from difficult births or complications before birth may be affected. Cerebral palsy does not get worse with time but in mild cases, the problem may not be noticed until the child is older and uses an adult-like gait.
What if my child now has a new limp?
This type of limp should always be evaluated by a doctor unless there is an obvious cause (i.e., rock in the shoe, cut on the foot). The possible causes of limping can be separated into groups based on the child’s age.
Infants (0-1 year of age)
If you can’t walk… you can’t limp!
Toddlers (1- 3 years of age)
Dysplasia of the hip – abnormal development of the hip joint. Develops before birth.
Infection in bone (spine, hip, knee, ankle, or foot) – this is called osteomyelitis and needs to be treated quickly to avoid permanent damage. Especially if fever or pain is present.
Infection in joints (hip, knee, ankle) – this also needs to be treated quickly to avoid permanent damage to the joint. Especially if fever or pain is present.
Infection in soft tissues – there may be an obvious infection on the skin or an infection hidden inside. Especially if fever or pain is present.
Injury – some injuries are unwitnessed and may not have outside evidence (i.e., bruises or scrapes).
Tumors – fortunately, these are rare.
School-age kids (4 – 18 years of age)
Infection – same as for toddlers
Injury – same as for toddlers
Transient synovitis – some viral infections can cause temporary, harmless inflammation in joints. You should ask your doctor to make sure it is not a more severe bacterial infection.
Legg-Calvé-Perthes disease (typically in kids ages 4 – 9 years, more common in boys) – this is caused by a lack of blood supply to the top of the femur (upper leg bone) at the hip joint. Damage can occur quickly or slowly over time. Damage may be permanent, resulting in permanent limping or disability. An x-ray of the hip can help with this diagnosis.
Slipped capital femoral head (typically affects children between 12 and 15 years of age, especially obese kids) – The top of the femur (upper leg bone) breaks and slips out of place at the hip joint. Treatment may involve a hip brace, a cast or surgery.
Tumors – fortunately, these are rare.
When should my child see a doctor?
Any new limp that can’t be explained by a simple problem (i.e., rock in the shoe, cut on the foot, known minor injury) should be evaluated by a doctor. This is especially true for children with a limp and other symptoms such as severe pain, fever, or limited motion of a joint.