An arm-length discrepancy occurs when one arm is shorter than the other arm. The difference can range from a fraction of an inch to several inches.

Some children are born with limb differences that cause arms to grow at different rates. Other limb-length discrepancies may occur due to an injury or other conditions. Injuries and conditions include fractures, bone infections and bone cysts.

Arm-length discrepancies are less likely to affect a child’s daily activities than leg-length discrepancies.

There are two types of limb-length discrepancies. Structural discrepancies occur when a bone in one limb is shorter than the same bone in the other limb. Functional discrepancies occur when joint contracture throws off limb symmetry

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What are the signs and symptoms of an arm limb-length discrepancy??

The signs of an arm-length discrepancy vary. It depends on the cause and difference in length. Signs or symptoms may include:

  • One arm that is shorter than the other; this is not always noticeable or obvious
  • Difficulty reaching something with both hands (e.g., reaching both handlebars)
  • Difficulty sitting in or standing using the arms of a chair

What causes an arm limb-length discrepancy?

There are several causes of arm discrepancies. Some limb-length discrepancies are congenital (present at birth) and others are illness-related.


  • Child’s arm did not develop fully during pregnancy (no known cause)


  • Complex fracture that does not heal correctly
  • Damage to the growth plate due to injury or bone infection
  • Bone tumors or bone cysts
  • Cerebral palsy and other neuromuscular disorders

How is an arm limb-length discrepancy diagnosed?

  • Physical exam
  • X-rays
  • Additional testing if necessary
    • Genetic testing
    • Testing of other parts of the body if a medical condition is suspected

How is an arm limb-length discrepancy treated?

Treatment for an arm limb-length discrepancy depends on the cause and extent of your child’s condition. There are several non-surgical and surgical treatments options to treat arm limb-length discrepancies:

  • Physical therapy
  • Occupational therapy
  • Assistive or adaptive devices
  • Prosthetics
  • Surgery to slow down or stop growth of the longer limb
  • Gradual lengthening of the shorter limb
  • Shortening of the longer limb
  • Reconstruction to parts of the hand, wrist and/or arm to improve alignment

Connecticut Children’s is equipped with state-of-the-art limb lengthening and limb modification technologies. Doctors at Connecticut Children’s can determine the right treatment plan for your child’s condition.