Aging, high BMI, high LDLc, occupational lifting, and sports activities are associated with DD. The results of this study raise our index of suspicion that cardiovascular risk factors and particular physical loading may contribute to DD; however additional studies are required to further investigate associations between DD and these factors.

Continuous competitive baseball and swimming activities during youth may be associated with disk degeneration. Furthermore, the study indicates that the experience of severe low back pain might be a predictor of disk degeneration in youth. The authors hope that preventive measures and management to protect against disk degeneration and low back pain in athletes will be established by further studies based on these results.

Excessive competitive swimming activities might exaggerate lumbar intervertebral disk degeneration, especially in the L5-S1 intervertebral segment.

Excessive exposure to competitive sports activities during youth was associated with low back pain and symptoms in the lower extremities, with the severity varying with the sport. To reduce low back pain in youth, factors that may be causing low back pain, such as sport-specific postures and motions, need to be investigated.

ObjectivesThis study aimed to clarify the trends of injury occurrence in the Japan national swim team for 15 years and to evaluate the effectiveness of the lumbar injury prevention project. It also aimed to verify the incidence of swimming-related injuries among swimmers by sex, age and swimming style.MethodsThe target group comprised 488 swimmers who participated in the Olympics, Asian Games and Universiade from 2002 to 2016; we compiled data for the total number of injuries in each body part. The lumbar injury prevention project started in 2008 and included two components (deep trunk muscle exercises and evaluation of lumbar disc degeneration using MRI). We analysed the prevalence of lumbar injury before (2002–2008) and after (2009–2016) implementation of the lumbar injury prevention project by χ2 test. We compared age, sex and swim strokes between the injured and non-injured groups by χ2 test and unpaired t-test.ResultsThe most common injury site was the lower back, followed by the shoulder and knee. The lumbar injury prevalence was significantly lower after implementation of the prevention project (23.5% vs 14.8%; p<0.05). Shoulder injuries were common in backstroke swimmers. The injury rate was significantly higher in female than in male swimmers. The injured group was significantly older than the non-injured group.ConclusionsLumbar injury prevention intervention might be effective to prevent lower back injury in swimmers. Injury risk factors included female and old age; younger female athletes should prevent the development of injuries as they mature.

Abstract.[Purpose] Therapeutic exercise for chronic low back pain is one of the most important conservative treatments. Recently, lumbar stabilization exercise focused on deep trunk muscles has attracted considerable attention. This study investigated the effectiveness of lumbar stabilization exercises for treating CLBP.[Subjects] The subjects were 18 patients with CLBP. CLBP was defined as pain that persisted for more than 3 months.[Methods] The therapeutic exercises involved the abdominal drawing-in maneuver (hereafter referred to as "drawing-in") and prone kneeling (hereafter referred to as "hand-knee"). The exercises were performed during a 3-month intervention period. Pain was evaluated using a Visual Analog Scale (hereafter referred to as "VAS"), while quality-of-life (hereafter referred to as "QOL") was estimated using the Japanese Orthopaedic Association Back Pain Examination Questionnaire (hereafter referred to as "JOABPEQ"). Pain and QOL were assessed prior to the intervention (T0), and at one (T1), three (T3), and six months (T6) after the intervention. The Steel-Dwass test was used to investigate differences between values prior to and after performance of the therapeutic exercise regime. Significance was defined as p<0.05.[Results] The median low back pain value was significantly improved at T3 and T6 compared to T0. At T1, patients reported significant improvement in the lumbar functions score in comparison with T0. This change was still observed at T3 and T6. At T3, scores of all items had significantly increased. At T6, the changes in low back pain score and walking ability score were no longer significant, however their tendencies remained. [Conclusions] These results suggest that performance of lumbar stabilization exercises is an effective method for improving comfort and QOL of patients with CLBP.

There is evidence in animal populations that loading and exercise can positively impact the intervertebral disc (IVD). However, there is a paucity of information in humans. We examined the lumbar IVDs in 308 young athletes across six sporting groups (baseball, swimming, basketball, kendo, soccer, and running; mean age 19 years) and 71 nonathletic controls. IVD status was quantified via the ratio of IVD to vertebral body height (IVD hypertrophy) and ratio of signal intensity in the nucleus to that in the annulus signal (IVD nucleus hydration) on sagittal T2-weighted magnetic resonance imaging. P values were adjusted via the false discovery rate method to mitigate false positives. In examining the whole collective, compared to referents, there was evidence of IVD hypertrophy in basketball (P ≤ .029), swimming (P ≤ .010), soccer (P = .036), and baseball (P = .011) with greater IVD nucleus hydration in soccer (P = .007). After matching participants based on back-pain status and body height, basketball players showed evidence of IVD hypertrophy (P ≤ .043) and soccer players greater IVD nucleus hydration (P = .001) than referents. Greater career duration and training volume correlated with less (ie, worse) IVD nucleus hydration, but explained less than 1% of the variance in this parameter. In this young collective, increasing age was associated with increased IVD height. The findings suggest that basketball and soccer may be associated with beneficial adaptations in the IVDs in young athletes. In line with evidence on other tissues, such as muscle and bone, the current study adds to evidence that specific loading types may beneficially modulate lumbar IVD properties.

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