I frequently get asked where you can find norms to measure core strength in children. As pediatric therapists, we sometimes use supine flexion, prone extension, modified sit ups and push ups as measures of core strength. I don’t usually refer to the norms but more look at the quality of how the exercise is performed and progress over time for each individual child. I do realize though that parents, teachers and administrators do like to understand norms to compare what a child should accomplish. The norms used for supine flexion and prone extension are older but seem to be the most referenced articles. If anyone knows of more updated, larger studies I would love to hear about them.
Supine Flexion – for each age group there were 40 participants. Lying in supine, children were instructed to hold the following position: cross arms, flex knees to 90 degrees and “roll into a ball” by flexing neck, upper trunk and hips. The results were recorded comparing boys to girls with the standard deviations ranging from 6.7 to 39.7.
SUPINE FLEXION (LEFKOF RESULTS)
AGE IN YEARS BOYS (SECONDS) GIRLS (SECONDS)
3 15.5 15.8
4 17 20.1
5 27.4 29.5
6 55.4 52
Reference: Marsha B Lefkof. Trunk Flexion in Healthy Children Aged 3 to 7 Years. PHYS THER January 1986 66:39-44
Prone Extension – There were 26 four year olds, 28 six year olds and 30 eight year olds in the study. They were instructed to lay on their stomach and lift up head, chest, arms and legs off the floor with knees straight and elbows bent. The standard deviation ranged from 5.67-13.45.
PRONE EXTENSION (HARRIS RESULTS) AGE IN YEARS POSITION HELD (SECONDS)
8 Every participant held position for 30 seconds
Reference: Harris, N. Duration and Quality of the Prone Extension Position in Four, Six and Eight Year Old Normal Children. AJOT. January 1981Vol 35 No 1.
PRONE EXTENSION 6-9 YEAR OLDS (BOWMAN & KATZ RESULTS) – 153 right hand dominant participants
AGE IN YEARS POSITION HELD (SECONDS)
Reference: Bowman, JO and Katz, B. Hand Strength and Prone Extension in RIght Dominant 6-9 Year Olds. Am J Occup Ther. 1984; 38(6):367-376. doi: 10.5014/ajot.38.6.367.
PRESIDENTIAL YOUTH FITNESS PROGRAM – The program uses FITNESSGRAM®, which provides an efficient way for physical educators to perform evidence-based health-related fitness assessments. Here is more info about the program and directions – http://www.pyfp.org/doc/fitnessgram/fg-07-muscular.pdf
BOYS AND GIRLS
AGE CURL UP(# COMPLETED) TRUNK LIFT (INCHES) PUSH UP (#COMPLETED)