Designing Health-referenced Standards for the Plank Test of Core Muscular Endurance

Abstract

ABSTRACT We developed plank test standards, based on trunk lean mass-to-fat mass (LM/FM) ratio, in a sample of healthy Portuguese 10–18 year olds (n = 474, 46.4% female). Height and weight were measured and muscular endurance was assessed using the prone plank test. Trunk LM/FM ratio was determined using dual-energy x-ray absorptiometry. Plank standards were derived using receiver operator characteristic curves. Approximately 90% of youth with sufficient trunk LM/FM ratio were categorized into the desirable zone of plank time. Roughly two-thirds of those with trunk LM/FM ratio ≤ 5th percentile were identified within the undesirable zone. The odds of low trunk LM/FM were 6.5 times greater for those in the undesirable zone of plank compared those scoring above the cutpoint (independent of age, sex, or weight status). The standards provided here can be used to identify low trunk LM/FM ratio, which may have implications for balance and spinal health in youth.