Computational modeling of posteroanterior lumbar traction by an automated massage bed: predicting intervertebral disc stresses and deformation.

Spinal traction is a physical intervention that provides constant or intermittent stretching axial force to the lumbar vertebrae to gradually distract spinal tissues into better alignment, reduce intervertebral disc (IVD) pressure, and manage lower back pain (LBP). However, such axial traction may change the normal lordotic curvature, and result in unwanted side effects and/or inefficient reduction of the IVD pressure. An alternative to axial traction has been recently tested, consisting of posteroanterior (PA) traction in supine posture, which was recently shown effective to increase the intervertebral space and lordotic angle using MRI. PA traction aims to maintain the lumbar lordosis curvature throughout the spinal traction therapy while reducing the intradiscal pressure. In this study, we developed finite element simulations of mechanical therapy produced by a commercial thermo-mechanical massage bed capable of spinal PA traction. The stress relief produced on the lumbar discs by the posteroanterior traction system was investigated on human subject models with different BMI (normal, overweight, moderate obese and extreme obese BMI cases). We predict typical traction levels lead to significant distraction stresses in the lumbar discs, thus producing a stress relief by reducing the compression stresses normally experienced by these tissues. Also, the stress relief experienced by the lumbar discs was effective in all BMI models, and it was found maximal in the normal BMI model. These results are consistent with prior observations of therapeutic benefits derived from spinal AP traction.

Computational Modeling of Deep Tissue Heating by an Automatic Thermal Massage Bed: Predicting the Effects on Circulation.

Automatic thermal and mechanical massage beds support self-managed treatment, including reduction of pain and stress, enhanced circulation, and improved mobility. As the devices become more sophisticated (increasing the degrees of freedom), it is essential to identify the settings that best target the desired tissue. To that end, we developed an MRI-derived model of the lower back and simulated the physiological effects of a commercial thermal-mechanical massage bed. Here we specifically estimated the tissue temperature and increased circulation under steady-state conditions for typical thermal actuator settings (i.e., 45-65°C). Energy transfer across nine tissues was simulated with finite element modeling (FEM) and the resulting heating was coupled to blood flow with an empirically-guided model of temperature-dependent circulation. Our findings indicate that thermal massage increases tissue temperature by 3-8°C and 1-3°C at depths of 2 and 3 cm, respectively. Importantly, due to the rapid (non-linear) increase of circulation with local temperature, this is expected to increase blood flow four-fold (4x) at depths occupied by deep tissue and muscle. These predictions are consistent with prior clinical observations of therapeutic benefits derived from spinal thermal massage.

Fitness as a determinant of arterial stiffness in healthy adult men: a cross-sectional study.

BACKGROUND: Fitness is known to influence arterial stiffness. This study aimed to assess differences in cardiorespiratory endurance, muscular strength, and flexibility according to arterial stiffness, based on sex and age. METHODS: We enrolled 1590 healthy adults (men: 1242, women: 348) who were free of metabolic syndrome. We measured cardiorespiratory endurance in an exercise stress test on a treadmill, muscular strength by a grip test, and flexibility by upper body forward-bends from a standing position. The brachial-ankle pulse wave velocity test was performed to measure arterial stiffness before the fitness test. Cluster analysis was performed to divide the patients into groups with low (Cluster 1) and high (Cluster 2) arterial stiffness. According to the k-cluster analysis results, Cluster 1 included 624 men and 180 women, and Cluster 2 included 618 men and 168 women. RESULTS: Men in the middle-aged group with low arterial stiffness demonstrated higher cardiorespiratory endurance, muscular strength, and flexibility than those with high arterial stiffness. Similarly, among men in the old-aged group, the cardiorespiratory endurance and muscular strength, but not flexibility, differed significantly according to arterial stiffness. Women in both clusters showed similar cardiorespiratory endurance, muscular strength, and flexibility regardless of their arterial stiffness. CONCLUSIONS: Among healthy adults, arterial stiffness was inversely associated with fitness in men but not in women. Therefore, fitness seems to be a determinant for arterial stiffness in men. Additionally, regular exercise should be recommended for middle-aged men to prevent arterial stiffness.

Impact of cardiac rehabilitation on angiographic outcomes after drug-eluting stents in patients with de novo long coronary artery lesions.

Cardiac rehabilitation (CR) can reduce cardiovascular mortality and morbidity in coronary artery disease. Long coronary artery lesions may be associated with adverse outcomes after drug-eluting stent (DES) implantation. The purpose of this study was to evaluate angiographic outcomes after a comprehensive CR program in patients with DESs for long coronary artery lesions. A total of 576 patients treated with DESs for long (≥25 mm) coronary lesions were enrolled in this prospective CR registry. Comprehensive CR programs were successfully performed in 288 patients (50%). The primary end point was in-stent late luminal loss at the 9-month angiographic follow-up. There were few significant differences between the CR and non-CR groups in terms of baseline characteristics, including clinical, angiographic, and procedural variables. The rate of in-stent late luminal loss in the CR group was 35% less than in the usual care group (0.19 ± 0.33 mm in CR vs 0.29 ± 0.45 mm in non-CR, difference 0.08 mm, 95% confidence interval 0.01 to 0.16, p = 0.02) at the 9-month follow-up. After propensity-matched analysis (224 pairs), the results were consistent (0.18 ± 0.31 mm in CR vs 0.28 ± 0.41 mm in non-CR, difference 0.10 mm, 95% confidence interval 0.02 to 0.18, p = 0.02). The CR group showed a significant improvement in the overall risk profile compared with the non-CR group, including current smoking, biochemical profiles, depression, obesity, and exercise capacity. In conclusion, the comprehensive CR program significantly reduced late luminal loss after DES implantation for long coronary lesions. This may be associated with significant improvements in exercise capacity and overall risk profile.

Therapeutic effects of tai chi in patients with Parkinson's disease.

Objective. The purpose of the study was to investigate the effects of a 12-week program of therapeutic Tai Chi on the motor function and physical function of idiopathic Parkinson's disease patients (PDs). Methods. The participants were 22 clinically stable PDs in Hoehn-Yahr stages 1-2 randomly assigned to a therapeutic Tai Chi group (TTC, N = 11) or a control group (CON, N = 9). Two subjects in control group did not complete the study for personal reasons. TTC was performed three days a week (60 min/session). Motor symptoms by the UPDRS were assessed, and tests of physical function were administered before and after the 12-week trial. Results. The TTC group, as compared to the CON group, showed changes in the mentation, behavior, mood, and motor scales of the UPDRS (P < 0.05, P < 0.01, resp.), with no significant main effects on the activities of daily living scale (ADL). However, there was a significant interaction between the time and intervention group on ADL (P < 0.05). There were no significant main effects for any of the physical function variables. There were significant interaction effects in balance and agility (P < 0.05, resp.). Conclusions. This study showed that TTC training had modest positive effects on the functional status of Parkinson's disease patients.

Effects of home-based pulmonary rehabilitation with a metronome-guided walking pace in chronic obstructive pulmonary disease.

Despite documented efficacy and recommendations, pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease (COPD) has been underutilized. Home-based PR was proposed as an alternative, but there were limited data. The adequate exercise intensity was also a crucial issue. The aim of this study was to investigate the effects of home-based PR with a metronome-guided walking pace on functional exercise capacity and health-related quality of life (HRQOL) in COPD. The subjects participated in a 12-week home-based PR program. Exercise intensity was initially determined by cardiopulmonary exercise test, and was readjusted (the interval of metronome beeps was reset) according to submaximal endurance test. Six-minute walk test, pulmonary function test, cardiopulmonary exercise test, and St. George's Respiratory Questionnaire (SGRQ) were done before and after the 12-week program, and at 6 months after completion of rehabilitation. Thirty-three patients participated in the program. Six-minute walking distance was significantly increased (48.8 m; P = 0.017) and the SGRQ score was also improved (-15; P < 0.001) over the six-month follow-up period after rehabilitation. There were no significant differences in pulmonary function and peak exercise parameters. We developed an effective home-based PR program with a metronome-guided walking pace for COPD patients. This rehabilitation program may improve functional exercise capacity and HRQOL.

Development and application of biological age prediction models with physical fitness and physiological components in Korean adults.

BACKGROUND: Several biological age (BA) prediction models have been suggested with a variety of biomarkers. Valid models should be able to measure BA in a relatively short time period and predict subsequent physiological capability. Physiological and physical fitness variables have been shown to be distinctive markers for predicting BA and morbidity. The practical and noninvasive nature of such variables makes them useful as clinical assessment tools in estimating BA for in-depth diagnosis and corresponding intervention. OBJECTIVE: To identify, develop and evaluate biomarkers and BA prediction models and validate their clinical usefulness for the practical diagnosis of functional aging. METHODS: Fourteen variables were measured in 3,112 male and 1,233 female participants aged 30 and older between the years 2004 and 2007. Through a series of parsimonious stepwise elimination processes, two sets of 8 gender-specific variables were selected as candidate biomarkers for 1,604 men and 760 women. Principal component analysis, linear regression analysis and adjustment methods were further applied to obtain two sets of true BA (TBA) prediction models. The TBA models were examined for validity by comparing TBA to the corresponding chronological age (CA) with clinical risk factors. RESULTS: TBA prediction models with r(2) values of 0.638 and 0.672 were developed, each unique to men and women, respectively. The overall mean TBA and CA of the participants were 53.9 and 51.8 years, respectively, with a marginal difference of -2.1 and -1.3 years. The regression slopes or rates of TBA as a function of CA were 1.00 and 1.28 for men and women with r values of 0.799 and 0.820 (p < 0.001), respectively. In comparing TBA to CA rates between healthy and clinical risk groups, both sarcopenic and obese groups showed significant increases in TBA. CONCLUSIONS: The selected biomarkers encompass various complex physiopathological factors related to intrinsic and extrinsic physiological and functional aging. The BA prediction models based on the selected biomarkers could be practical in assessing BA for Korean adults.

Effects of prolonged endurance exercise on vascular endothelial and inflammation markers.

Systemic inflammation has been found in association with vascular endothelial function for clinical implications including exercise-induced pathology. However, information on the relationship between the exercise-related inflammatory responses and endothelial function is limited. This study aimed to investigate the effects of prolonged endurance exercise on the expression of selected soluble adhesion molecules and inflammatory markers. Twenty-four middle-aged males participating in a 308 km ultra-marathon were recruited in this study. Venous blood was collected at baseline, 100 km, 200 km, and 308 km for the analysis of sVCAM-1, sE-selectin, leukocytes, hs-CRP, CK, and TNF-α. Significant increases of sVCAM-1, sE-selectin, and leukocytes were observed at 100 km. sVCAM-1 had the greatest significant increase at 100 km. In addition, sVCAM-1 was significantly associated with the running speed and leukocytes. sE-selectin was significantly associated with leukocytes, hs-CRP, TNF-α, and CK. Delayed rises in hs-CRP and CK were observed at 200 km. TNF-α fluctuated throughout the race with a significant increase at 308 km. Delayed onset of hs-CRP and continuously increased sE-selectin suggest anti-inflammatory responses to suppress pro-inflammatory markers such as TNF-α. Prolonged repetition of muscle contraction may have released delayed CK and significant rise in TNF-α toward the end of the race. The present study demonstrated an activation of the surrogate markers of endothelial dysfunction in relationship to exercise intensity and leukocyte trafficking without a significant activation of the inflammatory responses. Thus, alteration of the endothelium may be related to increased blood flow and shear stress put upon the endothelium in response to increased oxygen demand on the heart.