Normative reference values for strength and flexibility of 1,000 children and adults

Objectives: To establish reference values for isometric strength of 12 muscle groups and flexibility of 13 joint movements in 1000 children and adults, and investigate the influence of demographic and anthropometric factors. Methods: A standardized reliable protocol of hand-held and fixed dynamometry for isometric strength of ankle, knee, hip, elbow and shoulder musculature as well as goniometry for flexibility of the ankle, knee, hip, elbow, shoulder and cervical spine was performed in an observationa1 study investigating 1000 healthy males and females aged 3 to 101 years. Correlation and multiple regression analyses were performed to identify factors independently associated with strength and flexibility of children, adolescents, adults and older adults. Results: Normative reference values of 25 strength and flexibility measures were generated. Strong linear correlations between age and strength were identified in the first two decades of life. Muscle strength significantly decreased with age in older adults. Regression modelling identified increasing height as the most significant predictor of strength in children, higher body mass in adolescents and male gender in adults and older adults. Joint flexibility gradually decreased with age, with little gender difference. Waist circumference was a significant predictor of variability in joint flexibility in adolescents, adults and older adults. Conclusion: Reference values and associated age- and sex-stratified z-scores generated from this study can be used to determine the presence and extent of impairments associated with neuromuscular and other neurological disorders, monitor disease progression over time in natural history studies and evaluate the effect of new treatments in clinical trials