From the Research
A normal amount of hip abduction in a 9-month-old infant is approximately 70-80 degrees from the midline. This means when the baby is lying on their back, each leg should be able to move outward from the center of the body to form about a 70-80 degree angle. Full hip abduction is important at this age as it indicates proper hip joint development. Limited hip abduction (less than 60 degrees) could be a sign of developmental dysplasia of the hip (DDH) or other hip problems that would require medical evaluation.
The provided evidence does not directly address the normal range of hip abduction in a 9-month-old infant. However, it discusses the treatment of developmental dysplasia of the hip using the Pavlik harness and other methods 1, 2, 3, 4, 5. The studies focus on the effectiveness of the Pavlik harness in treating DDH, the age of treatment initiation, and the potential complications, but they do not provide information on the normal range of hip abduction in infants.
Given the lack of direct evidence, the recommendation is based on general knowledge of pediatric development and the importance of hip abduction in infancy. Hip abduction naturally decreases somewhat as children grow older, but during infancy, this wide range of motion is normal and necessary for proper development. The extensive abduction capability in infants exists because their hip joints are still developing, with more cartilage than bone, allowing for greater flexibility. If you notice your 9-month-old has asymmetrical hip movement or restricted abduction, it's essential to bring this to your pediatrician's attention promptly for assessment.
Some key points to consider:
- The Pavlik harness is a common treatment for developmental dysplasia of the hip in infants 2, 3, 4, 5.
- Early diagnosis and treatment are crucial for successful outcomes in DDH 1, 2, 3, 4.
- The age of treatment initiation and the duration of Pavlik harness use can impact the development of unaided sitting and independent walking in infants with DDH 5.
- It is essential to monitor infant development and address any concerns about hip movement or development with a pediatrician.