Anterior Limbus Vertebra and Intervertebral Disk Degeneration in Japanese Collegiate Gymnasts

Background: Magnetic resonance imaging (MRI) studies have shown that gymnasts have a high prevalence of radiologicalabnormalities, such as intervertebral disk degeneration (IDD) and anterior limbus vertebra (ALV). These 2 abnormalities may coexistat the same spinal level. However, the relationship between IDD and ALV remains unclear.Hypothesis: A significant relationship exists between IDD and ALV in Japanese collegiate gymnasts.Study Design: Case-control study.Methods: A total of 104 Japanese collegiate gymnasts (70 men and 34 women; age, 19.7 + 1.0 years) with 11.8 + 3.6 years ofsporting experience participated. T1- and T2-weighted MRIs were used to evaluate ALV and IDD.Results: The prevalence among the gymnasts of IDD and ALV was 40.4% (42/104) and 20.2% (21/104), respectively. Theprevalence of IDD was significantly higher in gymnasts with ALV than those without ALV, as determined using the chi-square test.Logistic regression analysis demonstrated a significant association between IDD and ALV (adjusted odds ratio [OR], 6.60; 95%confidence interval [CI], 2.14-20.35). IDD was further grouped by whether it was present in the upper lumbar region (L1-2, L2-3,and L3-4 disks) or in the lower lumbar region (L4-5 and L5-S1 disks). Upper IDD had a greater association with ALV (adjustedOR, 33.17; 95% CI, 7.09-155.25) than did lower IDD (adjusted OR, 6.71; 95% CI, 1.57-28.73).Conclusion: In Japanese collegiate gymnasts, ALV is a predictor of IDD, especially in the upper lumbar region.Clinical Relevance: Information regarding ALV is important to prevent IDD in Japanese collegiate gymnasts.Keywords: endplate lesion; gymnastics; intervertebral disk degeneration; magnetic resonance imagin

Discretized Wiener-Khinchin theorem for Fourier-Laplace transformation: application to molecular simulations

The Wiener-Khinchin theorem for the Fourier-Laplace transformation (WKT-FLT) provides a robust method to calculate numerically single-side Fourier transforms of arbitrary autocorrelation functions from molecular simulations. However, the existing WKT-FLT equation produces two artifacts in the output of the frequency-domain relaxation function. In addition, these artifacts are more apparent in the frequency-domain response function converted from the relaxation function. We find the sources of these artifacts that are associated with the discretization of the WKT-FLT equation. Taking these sources into account, we derive the new discretized WKT-FLT equations designated for both the frequency-domain relaxation and response functions with the artifacts removed. The use of the discretized WKT-FLT equations is illustrated by a flow chart of an on-the-fly algorithm. We also give application examples of the discretized WKT-FLT equations for computing dynamic structure factor and wave-vector-dependent dynamic susceptibility from molecular simulations

GRAVITATIONAL EFFECT ON GROWTH OF InX Ga1-XSb TERNARY BULK CRYSTALS

The effect of gravity on dissolution of GaSb in InSb melt and growth of InGaSb was experimentally investigated using GaSb(seed)/InSb/GaSb(feed) sandwich samples. Two parameters were considered: (1) the inclination angle of the sample for gravity as 0°, 53° and 90°, (2) the sample diameter (D) as 9 mm and 5mm. When θ =0°, the interface was almost flat whereas the interfaces were strongly distorted when θ = 53° and 90°. The undissolved GaSb(feed) remained for \theta = 0 °. However, it dissolved completely for θ = 90°, and partially for θ = 53°. As the gravitational angle was increased, the growth length of uniform composition became long. The decrease of sample diameter reduced the dissolution area of GaSb. These facts indicated that the dissolution and growth processes were strongly influenced by gravity

Changes in sagittal spinal alignment and comparison of deep trunk muscles contraction rate in low back pain of male high school soccer players

In spinal alignment, the posture cannot be maintained only by the bones and ligaments, and trunk rigidity is maintained by the presence of the surrounding trunk muscles. However, there are no reports of spinal alignment and trunk muscles in male high school soccer players. Purpose：In this study, we focused on spinal alignment and deep trunk muscles, to clarify the mechanism of low back pain （LBP） in male high school soccer players. Methods : The participants were 90 male high school soccer players. The presence of LBP was evaluated using a questionnaire. We assigned the participants into two groups : the non-LBP group （n = 58） and the LBP group （n = 32）.Results：Comparing the upright position with spinal alignment, a correlation was found between thoracic kyphotic angle （TKA） and lumbar lordosis angle （LLA） and between LLA and sacral inclination angle （SIA） in the non-LBP group. Conversely, in the LBP group, a correlation was found only between LLA and SIA, and no correlation was found between TKA and LLA. With regard to spinal alignment using the amount of change in the forward and backward bending positions, a correlation was found between LLA and SIA in the non-LBP group. By contrast, in the LBP group, a correlation was found between TKA and LLA, but no correlation was found between LLA and SIA. In addition, compared with the deep trunk muscles, the lumbar multifidus （LM） muscle contraction rate was lower in the LBP group than in the non-LBP group. Conclusion：This study suggests that changes in spinal alignment and decreased LM contraction rate may be involved in LBP in male high school soccer players