Quantitative Ultrasound at the Hand Phalanges in Adolescent Girls is Related to Their Overall Physical Fitness

Background. Growing of the skeleton, depends on genetic, health, nutritional and environmental influences. Objectives. The aim of the study was to assess the ultrasound properties of bone measured at hand phalanges in adolescent girls regarding the influence of pubertal status and level of physical fitness. Material and Methods. The study group was 56 adolescent girls aged 12-14 yrs, the controls were 86 girls matched for age, recruited from 1256 subjects undergoing bone measurement for screening purposes. The skeletal status (amplitude-dependent speed of sound - Ad-SoS) was assessed by quantitative ultrasound (QUS) at proximal phalanges using DBM Sonic 1200. Physical fitness was assessed by the Zuchora index and pubertal development by the Tanner scale. Results. The adolescent girls from our study group had greater body weight, height, BMI and Ad-SoS values than the controls. Overall physical fitness was highest in girls with the lowest BMI and lowest in girls with the highest BMI values. The highest results of the Ad-SoS were reported in girls presenting highest level of physical fitness. They were statistically significantly higher than in girls with a minimal level of physical fitness. There was a statistically significant correlation between the overall physical fitness score and Ad-SoS results. No correlations between Ad-SoS and the Tanner scale, particular the elements of physical fitness (speed, jumping ability, flexibility, shoulder muscular strength, abdominal muscle strength) and BMI were shown. Conclusions. The bone properties assessed by QUS at the hand phalanges in adolescent girls aged 12-14 years depend on their overall physical fitness. Pubertal development, body size and particular elements of physical fitness, especially shoulder muscular strength, have limited influence.