ABSTRACT
[Purpose] This study aimed to evaluate the changes in lower-extremity muscle strength, balance performance, and body composition. [Participants and Methods] In this study, 21 healthy university students who underwent short-term whole-body vibration training without previous whole-body vibration training participated. The study design was randomized between-groups design. Participants were randomly assigned to one of the three groups; control, training, and whole-body vibration training. All participants completed a six-week training protocol comprising a first two-week training period, two-week rest period following the first training period, and second two-week training period. Over four periods, the participants' lower-extremity muscle strength, balance performance, and body composition were evaluated. Separate three-by-four repeated-measure analyses of variance, with three exercise mode groups and four periods, were initially used to analyze the primary outcome variables; lower-extremity muscle strength, balance performance, and body composition. [Results] In the three groups, lower-extremity muscle strength, static and dynamic balance performances, and body composition showed no changes during all periods. [Conclusion] This study provides a better insight on the responsiveness of short-term whole-body vibration training and will help determine whole-body vibration programs in revalidation and training.
ABSTRACT
Low back pain is a significant public health problem worldwide. Intervertebral disc degeneration is most significant known risk factor for low back pain. Yet the mechanisms of degeneration remain relatively unknown. Carbonyl stress and oxidation have been implicated in cartilage and fibrocartilage degeneration. Here we investigate the role of oxidative stress and carbonyl production in the intervertebral disc after mechanical injury using an in vitro organ model of the mouse functional spine unit. We use a single-stab insult to model mild injury, and the three-stab insult to model severe trauma. Our results indicate that mild injury increases the carbonyl response that may be required for tissue repair, while severe trauma tempers this response and rapidly accelerates degeneration.
ABSTRACT
[Purpose] The purpose of our study was to clarify temporal effects on restrictions to range of motion and the histopathological changes of joint components after joint immobilization in a rat knee-contracture model. [Subjects] Fifty-four male Wistar rats were randomly divided into two groups: a fixation group, and a control group. [Methods] In the fixation group, unilateral knee joints were immobilized at full flexion using a plaster cast for 4 weeks. At four weeks the animals were randomly divided into six subgroups, corresponding to the time of examination after cast removal: 0, 4, 8, 16, 24, and 32 weeks. For comparison, control group animals of corresponding age were also examined. [Results] Although movement restrictions of the knee joint had completely recovered 6 weeks after the cast removal, cartilage and synovial membrane structures did not completely recover. [Conclusion] These findings have not previously been reported, and as they form an addition to the fundamental scientific foundations of physical therapy, further research must examine these findings from a variety of perspectives.
ABSTRACT
Immobilization is often associated with decreased muscle elasticity. This condition is known as muscle contracture; however, the mechanism remains unclear. The purpose of this study was to clarify the mechanism governing muscle contracture in rat soleus muscle by identifying changes in ankle joint mobility, insoluble collagen concentration and type I and type III collagen isoforms following 1- and 3-week immobilizations. Following a 1-week immobilization, range of motion (ROM) of dorsiflexion declined to 90% of the control value; additionally, ROM dropped to 67.5% of the control value after a 3-week immobilization. This finding suggested that ankle joint mobility decreases in conjunction with extended periods of immobilization. Insoluble collagen concentration in soleus muscles, which was unchanged after 1 week of immobilization, increased 3 weeks after immobilization. These results may be indicative of collagen fibers with strong intermolecular cross-links contained in the muscle was made increased relatively by 3 weeks of immobilization. Therefore, the change in intermolecular cross-links may be significant in terms of progress of muscle contracture with longer periods of immobilization. On the other hand, the ratio of type III to type I collagen isoforms in muscular tissue increased following a 1-week immobilization; moreover, this ratio remained constant after 3 weeks of immobilization. These data suggested that muscle immobilization may induce type III collagen isoform expression. The increase in the ratio of type III to type I collagen isoforms do not change in parallel with the increase in the limitation in ROM; however, this phenomenon probably is not closely related to the progress of muscle contracture. The change of collagen isoform in immobilized muscle may be involved in the mechanism governing the progression of muscle fibrosis.
