Validity of Stature-predicted Equations using Knee Height for Elderly and Mobility Impaired Persons in Koreans

OBJECTIVES: This study aimed to establish a stature-predicted equation using knee height, and perform a clinical validation on a Korean population. METHODS: Using nationwide data obtained from 'Size Korea 2004', a stature-predicted equation was drawn and cross validation was performed using knee height in 5,063 subjects (2,532 males, 1,785 premenopausal females, and 746 postmenopausal females) who were aged between 20 and 69 yr. The formula was then applied to an elderly group (7 males and 26 females) and a mobility-impaired group (25 males and 14 females) in a real clinical setting. A stature-predicted equation was estimated using knee height and age based on multiple linear regression analysis. Cross validation was performed using paired t-test, and validation using clinical data was performed using Wilcoxon signed rank test. RESULTS: In three groups (males, premenopausal females, and postmenopausal females), a cross validation was performed for a stature-predicted equation which was drawn using knee height and age. There were no significant differences between recorded height and estimated height in the elderly group (mean difference±interquartile range (IQR): male 0.65±4.65 cm, female -0.10±3.65 cm) and the mobility-impaired group (mean difference±IQR: male -0.23±5.45 cm, female 1.64±5.36 cm). CONCLUSION: If several limitations could be overcome, the Korean-specific equations using knee height drawn from this study could be applied to actual clinical settings with Korean elderly or mobility-impaired people.