Normal Range of Motion in Children of All Ages
When it comes to treating hip problems in children, it would be helpful to know what is normal motion and what is not. Other measures of things like grip strength, height, weight, head circumference, and even IQ (intelligence quotient) have normative values. Normative values means you can find a chart with the expected measurements for each of these areas based on age and sex (male and female).
Although we have some general guidelines for range-of-motion measurements in adults, normative values for children of varying ages are not available. Hence this study was done to determine what constitutes normal (versus abnormal) hip motion in normal, healthy children.
The study was done at Children's Hospital of Philadelphia (CHOP). Hip measurements were taken of children who came to the hospital for treatment of a broken arm. There were no leg injuries or other compromising health conditions. There were 252 children involved in the study (that's 504 hips to measure).
Measurements were taken in two positions lying down: supine (face up) and prone (face down). Measurements taken in the supine position included flexion, abduction (leg away from the midline), adduction (leg toward the midline), and rotations (internal and external). Extension and rotations were measured from the prone position.
Photos demonstrating the measurement techniques and patient positions were provided. The authors also gave a detailed explanation of the statistical tools used and analysis conducted. A graph showing the range and averages over time for each measured motion was included based on age and sex.
In addition, the authors provided a table with a review of the normative hip motions for adults based on the report of four very well-known researchers in this area (Kendall, Daniels and Worthingham, Hoppenfeld, Mohr).
In general, it appears that hip range-of-motion decreases as children get older. This effect is more obvious in boys than in girls. Differences between boys and girls at different ages are presented but the study was not designed to compare differences based on race (e.g., Whites, Blacks, Hispanics, Asians). That will be something future researchers may address.
The information gathered in this study will help physicians evaluating children for problems such as slipped capital femoral epiphyses (SCFE), synovitis or other inflammatory hip problems, and femoroacetabular impingement. Such diagnoses depend on altered range-of-motion as a primary measure. To really help in the evaluation of all pediatric hip diseases, the additional information about differences based on race will be needed.
Wubhav N. Sankar, MD, et al. Hip Range of Motion in Children: What is the Norm? In Journal of Pediatric Orthopaedics. June 2012. Vol. 32. No. 4. Pp. 399-405.