The objective of this study was to examine biological growth and development in skating performance by focusing on thigh muscle thickness and anaerobic power output capacity in Japanese speed skaters. One hundred thirty-three male and 96 female skaters aged from 10 to 22 years old were tested in this study. The anterior (MTA) and posterior (MTP) thicknesses of the thigh muscles were measured by the B-mode ultrasonic method. Maximal anaerobic power output capacity (MAP) was determined using a bicycle ergometer. The mean 500 m skating velocity (SV), calculated from recently attained individual best times, was used as a measure of skating performance. These parameters, along with height, were plotted on a logarithmic graph to obtain the allometric equation y=bx^a, where “a” is a growth index.There were two sharp bends in the graph showing the relationships between MTA, MTP, MAP, SV and body height in both males and females. The growth indexes “a” between the first and second changing points in all the above relationships were observed to be larger than the other phases. Ranges of body height between the first and second changing point in muscle thicknesses (MTA, MTP) ranged from 152.2-154.8 cm to 168.1-168.3 cm in males, and from 142.8-144.9 cm to 154.4-157.6 cm in females. The ranges of MAP were from 139.8 cm to 166.8 cm in males, and from 138.8 cm to 157.8 cm in females. However, the height ranges of SV were from 147.4 cm to 167.8 cm in males, and from 142.2 cm to 153.2 cm in females.From these results, it was suggested that accelerated development of skating performance and anaerobic power output capacity begins earlier than muscle structural development in speed skaters.

STUDY DESIGN: A cross-sectional study. PURPOSE: To clarify the prevalence of chronic nonspecific low back pain (CNSLBP) and its associated factors among middle-aged and elderly Japanese individuals using data from a musculoskeletal examination conducted in general Japanese populations. OVERVIEW OF LITERATURE: Most studies evaluating low back pain-associated factors have been conducted in Western countries, but they have not always evaluated CNSLBP. METHODS: We obtained data on 213 subjects aged >50 years who responded to a survey regarding age, gender, body mass index, lifestyle-related diseases (diabetes mellitus, hypertension, and hyperlipidemia), glucocorticoid use, smoking and alcohol-drinking habits, labor intensity, and chronic low back pain (CLBP) and underwent screening for lumbar spinal stenosis, evaluation for quality of life (QOL), and evaluation for specific spinal pathology via thoracolumbar spine X-rays. We investigated the prevalence of CNSLBP and association between CNSLBP and measured variables. RESULTS: The prevalence of CNSLBP and chronic specific low back pain (CSLBP) was 15.4% and 9.3%, respectively. Among the subjects with CLBP, 62.2% had CNSLBP. In age-adjusted logistic models, smoking habits (p=0.049, odds ratio [OR]=2.594), low back pain (p < 0.001, OR=0.974), lumbar function (p=0.001, OR=0.967), and social function (p=0.023, OR=0.976) in the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were significantly associated with CNSLBP, whereas EQ-5D utility score (p=0.024, OR=0.068), low back pain (p=0.007, OR=0.981), lumbar function (p=0.001, OR=0.963), walking ability (p=0.001, OR=0.968), and social function (p=0.002, OR=0.966) in JOABPEQ were significantly associated with CSLBP. CONCLUSIONS: CNSLBP among middle-aged and elderly individuals was associated with smoking habits and decreased QOL; however, CSLBP was considered to be more multilaterally associated decreased QOL.
Aged* ; Asian Continental Ancestry Group ; Back Pain ; Body Mass Index ; Cross-Sectional Studies ; Humans ; Hypertension ; Japan* ; Logistic Models ; Low Back Pain* ; Mass Screening ; Odds Ratio ; Pathology ; Prevalence* ; Quality of Life ; Smoke ; Smoking ; Spinal Stenosis ; Spine ; Walking

STUDY DESIGN: Cross-sectional study. PURPOSE: The purpose of this study was to evaluate the correlation between pelvic tilt (PT) and the sacro-femoral-pubic (SFP) angle, which is easier to identify than PT, in middle-aged and elderly Asian subjects from the general population. OVERVIEW OF LITERATURE: Measuring PT is important in the diagnosis and treatment of adult spinal deformity. However, identifying femoral heads, which are necessary to determine PT, using sagittal radiographs is often difficult. METHODS: Standing coronal and sagittal pelvic radiographs of individuals aged more than 50 years were taken during a local medical examination. The subjects were divided into female, male, and total groups at the time of evaluation. Linear regression analysis was performed to investigate the relationship between PT and the SFP angle, which were obtained from the X-rays. RESULTS: The present study included 291 subjects. There were no statistically significant differences between the left and right SFP angles, and there was gender difference regarding the SFP angle. However, a gender difference was observed regarding PT. The correlation between PT and the SFP angle was substantiated in each group. Pearson's correlation coefficients between PT and the SFP angle in the total, female, and male groups were 0.696, 0.853, and 0.619, respectively. In the linear regression analysis, PT was calculated as follows: PT=60.1−0.77×(SFP angle) in the total group, PT=62.8−0.80×(SFP angle) in the female group, and PT=51.5−0.64×(SFP angle) in the male group. CONCLUSIONS: A significant correlation between PT and the SFP angle was observed in middle-aged and elderly Asian subjects from the general population.
Adult ; Aged* ; Asian Continental Ancestry Group* ; Congenital Abnormalities ; Cross-Sectional Studies ; Diagnosis ; Female ; Head ; Humans ; Linear Models ; Male ; Pelvis ; Spine