An estimation of grip strength during puberty.

OBJECTIVE: Find the correlation of grip strength in puberty with chronological age, height, weight, and percentage of body fat. MATERIAL AND METHOD: One thousand one hundred and five volunteer students between 11 and 14 years of age in Central Thailand participated in the study. The body weight and height were measured with standard balance and stadiometer The percentage of body fat was measured with Near Infrared interactance device. The grip strength was measured with Digital Handgrip Dynamometer The results were statistically analyzed by multiple linear regression. RESULTS: It was found that grip strength has a significant correlation with age, height, and weight but not with percentage of body fat. The prediction of grip strength in puberty can be estimated with the following equations: a) For boys, Grip strength (kg) = -59.797 + 2.493 Age (yr) + 0.308 Height (cm) + 0.147 Weight (kg), and b) For girls, Grip strength (kg) = -32.887 + 0.926 Age (yr) + 0.236 Height (cm) + 0.155 Weight (kg). CONCLUSION: The predictive value of an age, height, and weight equation is more precise than that of solely chronological age.

Normal value of bone mineral density of lumbar spine, proximal femur, and distal forearm of women in different age groups.

The cross sectional, descriptive study was conducted to find the reference data for bone mineral density (BMD) in normal women in the area around Thammasat University Hospital. The study population consisted of 806 women aged 15-80 years. BMD of different parts of the body were measured by dual energy photon absorptiometer. The results showed that mean (+/- SD) BMD of the lumbar spine 2, 3, 4, neck of femur, Ward's triangle of femur, greater trochanter of femur, ultradistal part of radius, and distal ulnar averaged from all age groups were 0.954 +/- 0.144, 1.027 +/- 0.151, 1.059 +/- 0.147, 0.898 +/- 0.114, 0.774 +/- 0.165, 0.777 +/- 0.103, 0.412 +/- 0.073, and 0.585 +/- 0.096 g/cm2 respectively. Overall, the peak BMD was between the age of 40-44 years old. It started decreasing from the age of 45 and decreased remarkably after the age of 50. The data is shown to be a database for our hospital's health policy, but the authors believe that it could also be used as reference data for future studies in Thailand. It is suggested that normal values in different areas should be available in the future in order to provide more specific and better health care according to demographic variation.