Date of Paper/Work


Type of Paper/Work

Research Project

Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

First Advisor

Jaynie Bjornaraa



The importance of core stability in activities of daily living, athletic performance, and in preventing low back pain (LBP) and extremity injuries is becoming increasingly accepted and better understood in modern literature. However, normative values for current core endurance tests have yet to be validated for clinic use. The purpose of this research project was to determine core endurance strength normative values for three core endurance tests in healthy men and women between the ages of 18 and 55 years old.


One-hundred-sixteen subjects (76 female and 40 male) with a mean age of 28.8 years participated in this study over a two-year period. Subjects completed a general health and exercise history questionnaire. Each subject was randomly assigned a test order and was tested by one of nine student researchers. The core endurance tests performed were the 60 degree flexion test (Fl), trunk extensor endurance test (Ext), right side plank (RSP), and left side plank (LSP). Analysis included a one-way ANOVA and multiple regression to determine differences between groups and to understand what variables influenced test outcomes.


Normative mean values in seconds for each test are: Fl 160(102); Ext 101(51); RSP 54(25); LSP 55(28). One-way ANOVA revealed the following significant differences: gender M/F (RSP p=.00, LSP p=.00), exercise Y/N (RSP p=.03, LSP p=.01, Fl p=.000), active runners Y/N (RSP p=.001, LSP p=.005, Fl p=.001), strength training Y/N (RSP p=.001, LSP p=.000), core exercise Y/N (LSP p=.01), competitive athletes Y/N (RSP p=.01, LSP p=.02, Fl p=.04). Total time of all four tests noted significant differences for exercise Y/N (p=.005) and run Y/N (p=.003), but revealed no significant difference between gender. Multiple regression models revealed that exercise and core time were significant predictors of LSP. Exercise time was a significant predictor of Fl test, and age and waist circumference were significant predictors for Ext test. The overall model for RSP displayed a trend toward significance.


Our results suggest that normative values can be established for the Fl and Ext tests regardless of gender, however RSP and LSP tests were significant for differences between genders. The results also suggest that increased activity level improved core endurance.