Preoperative ultrasound Doppler study and clinical correlation of free posterior interosseous flap

Age-related loss of strength contributes to impaired mobility and increases the risk of falls. Recent research has focused on 2 approaches to preventing age-related loss of strength--promoting physical activity and exercise (especially strength training) and using trophic factors to enhance muscle performance. Epidemiologic evidence strongly supports a role of regular physical activity in successful aging by preserving muscle performance, promoting mobility, and reducing fall risk. Randomized controlled trials provide convincing evidence that strength and endurance training improve muscle performance in older adults. Evidence is rapidly accumulating from randomized trials that endurance, strength, and balance training promote mobility and reduce fall risk, though exercise effects differ according to the type of exercise, details of the exercise program, and the target group of older adults. Because lifetime regular physical activity is recommended for all older adults, a reasonable strategy (especially for weak adults) is an activity program that includes strength training. In contrast, insufficient evidence exists to recommend the long-term use of trophic factors to preserve muscular performance. An intervention that merits additional study is avoiding the use of psychoactive drugs because drugs like benzodiazepines appear to be risk factors for inactivity and may have unrecognized direct effects on muscular performance. Because chronic illness is a risk factor for inactivity and disuse muscle atrophy, randomized trials comparing strength training with other interventions would be useful in understanding whether strength training has advantages in preserving muscle performance and improving health-related quality of life in a variety of chronic illnesses such as depressive illness.     

Is exercise good or bad for arthritis in the elderly?

Recreational exercise has achieved great popularity. Possible benefits to participants include increased longevity, decreased risk of cardiovascular disease, improved psychologic well-being, and greater fitness. Important but as yet incompletely answered concerns are whether exercise or physical overuse conditions play a role in the pathogenesis of osteoarthritis, which is virtually universal among the elderly, and whether there are any circumstances in which exercise might be beneficial for elderly patients with arthritis. In humans, anecdotal observations have suggested relationships between certain recreational activities and degenerative joint disease. The few controlled studies that exist, however, have indicated that exercise need not be deleterious to joints. Available data may be interpreted to suggest that reasonable recreational exercise--carried out within limits of comfort, putting joints through normal motions, and without underlying joint abnormality--need not inevitably lead to joint injury, even over many years. We are also witnessing thoughtful reevaluation of physical exercise as a therapeutic modality for arthritis patients. It is possible that certain patients may achieve psychologic and clinical benefit from selected exercise programs.     

Seismic Behavior and Retrofit of Outrigger Knee Joints

Experimental tests were conducted on six 1/3-scale specimens to define the vulnerabilities of existing outrigger bents under in-plane and out-of-plane seismic loading and to develop retrofit measures that address the identified vulnerabilities. The specimens represented knee joints in the SR 99 Spokane Street overcrossing in western Washington State but included deficiencies present in a number of older bridges. The as-built specimens failed at low ductility levels due to shear distress, low torsional strength of the outrigger beam, and reinforcement bond failures within the joint. Threshold principal tension stress values describing the expected condition of the joints were established and compared to values obtained by other researchers. Circular steel jackets were used to retrofit the as-built specimens. The retrofitted specimens developed plastic hinging in the column, with enhanced strength, energy, and ductility capacities. Design and detailing guidelines for retrofitting outrigger bents were proposed.     

Racial differences in muscle strength in disabled older women

This study examines racial differences in muscle strength, and associations of muscle strength to level of physical activity and severity of disability, among a community sample of 254 black and 665 white, moderately to severely disabled women aged 65 and older. Potential confounders that were adjusted for in the models included age, body weight and height, joint pain, number of chronic conditions, and socioeconomic status. Hand grip, hip flexion, and knee extension forces were measured using portable hand-held dynamometers in the participants' homes. Hand grip strength was measured as the maximal isometric force. Hip flexion and knee extension forces were measured as the greatest force the tester had to apply to break the isometric contraction. A declining strength gradient was observed with increasing severity of disability and for decreasing level of physical activity in both races. At equal levels of disability or physical activity, blacks had better hand grip and hip flexion strength, but knee extension strength did not differ by race. The greater hand grip and hip flexion strength found in black women may be related to their greater muscle mass and known racial differences in body dimensions. No consistent racial differences were observed in the relationship between physical activity and muscle strength, or muscle strength and disability, suggesting that the role of muscle strength in the disablement process does not differ between races. Physical activity and exercise programs may be feasible ways to prevent worsening of disability in blacks and whites.     

Individual risk factors for hip osteoarthritis: obesity, hip injury, and physical activity

Hip osteoarthritis is a major cause of pain and disability. The authors explored individual risk factors for hip osteoarthritis in a population-based case-control study. The study was performed in two English health districts (Portsmouth and North Staffordshire) from 1993 to 1995. A total of 611 patients (210 men and 401 women) listed for hip replacement because of osteoarthritis over an 18-month period were compared with an equal number of controls selected from the general population and individually matched for age, sex, and family practitioner. Information about suspected risk factors was obtained by a questionnaire administered at interview and a short physical examination. Obesity (odds ratio (OR) = 1.7, 95% confidence interval (CI) 1.3-2.4; highest vs. lowest third of body mass index), previous hip injury (OR = 4.3, 95% CI 2.2-8.4), and the presence of Heberden's nodes (OR = 1.6, 95% CI 1.2-2.2) were independent risk factors for hip osteoarthritis among men and women. Hip injury was more closely related to unilateral as compared with bilateral disease. There were a negative association between cigarette smoking and osteoarthritis among men and a weak positive association with prolonged regular sporting activity. Obesity and hip injury are important independent risk factors for hip osteoarthritis, which might be amenable to primary prevention. Hip osteoarthritis may also arise as part of the polyarticular involvement found in generalized osteoarthritis.     

Assessment of 3-D joint contact load predictions during postural/stretching exercises in aged females

Our goal was to estimate knee and hip joint contact forces during a variety of unconstrained "stretching" exercises that are often recommended for people with arthritis. The population of interest was aged females with and without significant osteoarthritis (OA). Three-dimensional (3-D) kinematic, force platform, and selected electromyographic (EMG) data were measured. A relatively standard and reasonably efficient technique was used for all subjects and tasks: inverse dynamics to estimate joint reaction forces and net moments, followed by heuristic reductionist techniques for predicting muscle load-sharing. Muscle force predictions were compatible with measured EMG activity for some tasks but less so for others, especially those with significant axial and medio-lateral movement components or high co-contraction. Such results suggest several improvements, which come at computational cost: 3-D joint models which better document muscle and passive tissue loading-sharing in abduction and axial torsion, and dynamic or novel static optimization approaches that can inherently predict muscle co-contraction. Nonetheless, the predicted joint contact loadings provide estimates that are essentially lower bounds on the likely joint contact loads. Based on our results we suggest that the side-kick and back-kick tasks be modified because the loading levels on the support leg are potentially excessive for the aged arthritic population.     

Changes in physical activity, mortality, and incidence of coronary heart disease in older men

BACKGROUND: We studied the relations between physical activity and changes in physical activity, all-cause mortality, and incidence of major coronary-heart-disease events in older men. METHODS: In 1978-80 (Q1), 7735 men aged 40-59 were selected from general practices in 24 British towns, and enrolled in a prospective study of cardiovascular disease, which included physical activity data. In 1992 (Q92), 12-14 years later, 5934 of the men (91% of available survivors, mean age 63 years) gave further information on physical activity and were then followed up for a further 4 years. The main endpoints were all-cause mortality during 4 years of follow-up from Q92, and major fatal and non-fatal coronary-heart-disease events during 3 years of follow-up from Q92. FINDINGS: Among 4311 men with no history of coronary heart disease, stroke, or "other heart trouble" by Q92 and who did not report "poor health", there were 219 deaths. In the inactive/occasionally active, light, moderate, and moderately vigorous/vigorous activity groups there were 101 (18.5/1000 person-years) 48 (11.4), 23 (7.3), and 47 (9.1) deaths, respectively (adjusted risk ratios 1.00, 0.61 [95% CI 0.48-0.86], 0.50 [0.31-0.79], 0.65 [0.45-0.94]). Men who were sedentary at Q1 and who began at least light activity by Q92 had significantly lower all-cause mortality than those who remained sedentary, even after adjustment for potential confounders (risk ratio=0.55 [0.36-0.84]). Physical activity improved both cardiovascular mortality (0.66 [0.35-1.23]) and non-cardiovascular mortality (0.48 [0.27-0.85]). The relation between physical activity at Q92, changes in physical activity, and mortality were similar for men with pre-existing cardiovascular disease. INTERPRETATION: Maintaining or taking up light or moderate physical activity reduces mortality and heart attacks in older men with and without diagnosed cardiovascular disease. Our results support public-health recommendations for older sedentary people to increase physical activity, and for active middle-aged people to continue their activity into old age.     

Radiologic prevalence of advanced lateral C1-C2 osteoarthritis

STUDY DESIGN: The lateral C1-C2 (atlantoaxial) joints were evaluated retrospectively in 355 patients referred for radiographs of the paranasal sinuses. OBJECTIVES: To determine the radiologic prevalence of advanced lateral atlantoaxial osteoarthritis. SUMMARY OF BACKGROUND DATA: Previous studies have shown a relation between atlantoaxial osteoarthritis and referred pain in the suboccipital region. However, the radiologic prevalence of this degenerative disorder is unknown. METHODS: Five hundred radiographs of the paranasal sinuses were evaluated retrospectively. Both lateral atlantoaxial joints were clearly visible on occipitofrontal projections in 355 examinations. Each lateral atlantoaxial joint was considered severely degenerated when advanced narrowing or obliteration of the joint space, subchondral sclerosis, and/or osteophytosis were present. RESULTS: Atlantoaxial osteoarthritis was found in 4.8% of the patients. The radiologic prevalence of advanced degenerative changes at the lateral atlantoaxial joint(s) was found to increase with age, ranging from 5.4% in the sixth decade to 18.2% in the ninth decade of life. CONCLUSION: Because advanced degenerative changes at the lateral atlantoaxial joints can cause suboccipital neck pain, these findings should be included in the differential diagnosis in older patients with this symptom.     

Lack of an association between insulin-like growth factor-I and body composition, muscle strength, physical performance or self-reported mobility among older persons with functional limitations

OBJECTIVE: The hypothesis that decreased growth hormone (GH) secretion contributes to the functional decline that occurs with aging is far from substantiated. There have been few studies addressing the distribution and correlates of IGF-I, an indicator of GH activity, in nonclinical populations. As part of a growth hormone intervention trial, we examined the cross-sectional relations between IGF-I levels and multiple measures of physical function, body composition, and strength in a group of older men and women exhibiting mild to moderate reductions in measured physical performance. METHODS: Using a variety of advertising techniques, 155 older subjects were recruited from a metropolitan area to participate in a growth hormone and exercise intervention study. At baseline, all subjects had blood drawn for IGF-I and underwent testing of body composition using dual X-ray absorptiometry, muscle strength using isokinetic dynamometry, and functional assessment using timed performance measures and self-report. Associations between levels of IGF-I, body composition, strength, and physical function were assessed after dividing men and women separately into tertiles of IGF-I as well as treating IGF-I as a continuous variable. RESULTS: Men had higher IGF-I levels than women, and a significant inverse correlation was observed between age and IGF-I in men (r=-0.29, P=.009). There were no clear trends for associations between tertiles of IGF-I, and any of the variables tested. Linear regression models with IGF-I treated as a continuous measure were not associated significantly with any of the measures of physical function, body composition, or strength (all P > 0.05). CONCLUSIONS: In conclusion, although IGF-I levels declined with age in men, these data did not demonstrate an association between IGF-I and measures of muscle strength, body composition, or physical functioning. These findings support the growing body of evidence that IGF-I levels may not be an indicator of growth hormone activity in older persons.     

Genetic and behavioral risk factors for self-reported joint pain among a population-based sample of Swedish twins.

Self-reported joint pain, a typical manifestation of osteoarthritis, was examined using 335 twin pairs from the Swedish Adoption/Twin Study of Aging to estimate relative genetic and environmental influences on self-reported joint pain and to examine the relationship between joint pain, health behavior, and psychological variables. Findings suggest that family resemblance for self-reported joint pain represents similar environments more than genetic similarity. Data from the early 1970s, including exercise, physical activity at work, obesity, and neuroticism, were used to predict joint pain in 1993. For men, moderate amounts of exercise decreased the likelihood of joint pain, but strenuous amounts of physical activity in the workplace had the opposite effect. For women, exercise and physical activity were not significant predictors, but past obesity and higher levels of neuroticism increased the likelihood of reporting joint pain in 1993. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low back exercises: evidence for improving exercise regimens

Despite the wide variety of exercises that are prescribed for the low back, the scientific foundation to justify their choice is not as complete as one may think, or expect. Thus, the clinician must often call upon "clinical opinion" when selecting exercise. Given that low back tissues may need stressing to enhance their health but too much loading can be detrimental, choosing the optimal exercise requires judgment based on clinical experience and scientific evidence. To assist in developing better exercise programs, this review documents some recent biomechanical evidence from my laboratory and from laboratories of other researchers that has been reported in various publications in an attempt to update clinicians on issues of low back exercise. Among the issues examined are mechanisms of injury; the relative importance of "strength" (ie, maximum force a muscle can produce during a single exertion to create joint torque), "flexibility," and "endurance"; and training to enhance stability. Finally, some specific exercises are described that have been shown to challenge muscle and enhance performance but that are performed in such a way as to minimize loading of the spine to reduce the risk of injury exacerbation. These exercises form a basic program for rehabilitation and maintenance of low back health.     

Leisure and occupational physical activity and risk of colorectal adenomatous polyps

Multiple studies have shown a protective effect for physical activity on the incidence of colorectal cancer, but few have addressed its association with incident adenomas and none have investigated its association with metachronous adenomas. We interviewed 2,001 patients undergoing colonoscopy in 3 New York City practices between 1986-1988. Of these, 298 had a first diagnosis of adenomas, 506 had normal colonoscopies, 197 had metachronous adenomas and 345 had normal colonoscopies with a past history of adenomas. Subjects were queried regarding use of moderate amounts of recreational exercise (swimming, jogging, biking, racket sports and other sports) on a regular basis, and were also asked to estimate their level of physical activity. Occupational physical activity was assessed through a blinded coding of occupational titles. After adjusting for age, years of education, body mass index, total caloric intake, dietary fiber intake, dietary fat intake and years of cigarette smoking, protective effects of borderline significance were observed among males for leisure physical activity for metachronous and incident cases. Occupational physical activity was found to be significantly protective in male incident cases. Men with increased levels of either occupational or leisure activity showed a reduction for incident and metachronous cases. No effects were observed for females. Thus, in this study, both leisure and occupational physical activity were associated with a reduced risk of incident and metachronous adenomas among men but not women.     

SHPB加载作用下考虑节理分形的闭合变形性质研究

为了探讨动载荷作用下的节理闭合变形性质,用水泥砂浆制作出含节理的人工试样,并采用SHPB装置对具有不同分形（JRC）的含节理试样进行不同加载率作用下的冲击试验,获得了不同加载率下具有不同Barton标准 JRC值的节理动态闭合变形曲线。冲击后试样及其结果分析显示：随着加载率的增加,碎裂的块数明显增加,表现出较强的加载率相关性;节理闭合变形曲线的变化趋势基本不受加载率的影响,节理变形量δ均随着应力σ的增大而增大。在加载速率相同的情况下,不同节理形貌试样的节理法向变形量存在较大差异;具有相同节理的试样在不同加载率作用下的闭合变形曲线也是显著不同的;无论加载率多大,δ和σ之间均具有很强的指数关系,可用统一的公式表达。该研究成果为进一步开展动载荷作用下节理闭合变形本构方程研究提供了试验基础。     

Yohimbine, erectile capacity, and sexual response in men

In this study we investigated the hypothesis that cartilage from defined regions of ovine stifle joints, which were subjected to differing mechanical stresses, contained phenotypically distinct chondrocyte populations. Chondrocyte phenotypes were identified by the relative biosynthesis of the proteoglycans (PGs) aggrecan, biglycan and decorin. Articular cartilage (AC) from adult and neonatal ovine stifle joints were examined. Cells were cultured as both full-depth AC explants and in alginate beads after their isolation from the AC matrix. When chondrocytes from the various topographical regions of adult ovine knee joints were cultured as explants they demonstrated a consistent difference with regard to the metabolism of aggrecan and decorin. Significantly, this topographically-dependent phenotypic expression of PGs was preserved when the chondrocytes were cultured in alginate beads. In adult joints, chondrocytes from the central region of the tibial plateau not covered by the meniscus, which is subjected to high mechanical loads in-vivo, synthesized less aggrecan but more decorin than cells from regions covered by the meniscus. When chondrocytes from identical AC regions of neonatal ovine joints were cultured as explants, no topographical difference in aggrecan nor decorin metabolism could be detected. The results of this study, in association with the existing literature, lead us to propose that post-natal mechanical loading of AC could select for chondrocyte clones or induce a lasting modulation of chondrocyte phenotypic expression in different joint regions. Such cellular changes could result in the synthesis of PG populations that confer properties to AC most suited to resist the variable mechanical stresses in the different joint regions. This study serves to emphasize the importance of using cartilage from identical joint areas when examining PG metabolism by chondrocytes. Further investigation into the relationship between mechanical loading, regional chondrocyte phenotype selection and the response of these cells to anabolic and catabolic factors may provide important insights into the focal nature of AC degeneration in osteoarthritis.     

Backs to the future? Reflections on women, ageing and nursing

Physical activity protects against the development of chronic disease and disability. There appears to be little risk of damage to joints from regular, moderate-level exercise. Patients with arthritis can safely participate in exercise programs and often have relief of pain and disability. The most difficult problem facing practitioners is how to get people with arthritis to start and maintain an exercise program.     

Tumor necrosis factor in synovial fluids of temporomandibular joint dysfunction syndrome

With the MTT tetrazolium WEHI 164 clone 13 cell cytotoxicity assay, we measured TNF alpha (tumor necrosis factor) activity in synovial fluids of TMJDS (Temporomandibular joint dysfunction syndrome). We found no detected TNF alpha level from 5 patients with muscle dysfunction, raised TNF alpha levels from 5 of 11 patients with internal derangement and from 9 of 11 patients with organic destruction (osteoarthritis). The findings of biologically active TNF alpha in synovial fluids of TMJDS suggest that TNF alpha may play a role in the pathogenesis of TMJDS.     

Sports medicine and rehabilitation. Surface and footwear

Load on the human body can be influenced by shoes and surfaces which is important both in sports and rehabilitation. The loading which can primarily be influenced are impact situations and friction as well as the stability of the foot. This stability is of main interest in the prevention of pain and injury. However, a certain amount of loading is necessary to improve strength and structure of biological materials. In the past, the development of shoe and surface materials has hardly been perceived under this aspect, but may be increasingly important in the future.     

Understanding readiness for regular physical activity in older individuals: An application of the theory of planned behavior.

This study examined whether stage of readiness for regular physical activity (i.e., discrete phases from inactive to active) was related to beliefs concerning perceived social pressure, attitude, perceived control, and intention. Data were collected from 288 older people through the mail. Frequency data indicated that over 50% of the sample had been engaging in regular physical activity for longer than 6 months. Analysis of variance (ANOVA) results showed that all selected variables shared significant variance with stage of readiness, and discrimination among the stages by the selected variables was successful. Path analysis indicated that intention, attitude, and perceived control had direct relationships with stage of readiness. Discussion focused on the utility of these variables for understanding individual differences in stage of readiness for regular physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elderly persons in old-age homes. A medical, psychiatric and social investigation

A survey of 100 consecutive admissions to homes for elderly Whites in Cape Town showed that an interplay of social, physical and psychiatric factors was responsible for most of the referrals, although psychiatric factors contributed to more than 50% of them. The largest proportion (37%) suffered from confusional states, 31% were diagnosed as having a senile organic condition and 25% showed moderate to severe depression. These old people were physically very frail; 53% had incapacitating muscular weakness or stiff and painful joints, 35% had a significant degree of deafness, 25% had a visual defect and 23% were incontinent. The findings indicate that old-age homes deal with a considerable amount of physical and mental ill health, and they are therefore an essential part of health services. The residents of old-age homes were much older than elderly people in the community, as well as being more socially isolated and very disadvantaged in terms of income and family and social support.     

Exercise and sports in the adolescent with chronic pulmonary disease

Every young person with a respiratory disability should be given the opportunity to maximize his or her exercise potential. Conditions such as asthma, affecting some 14 to 15 million people and cystic fibrosis (CF), affecting about 30,000 people in the U.S., may exclude young people from sports participation. And yet regular aerobic exercise and weight training have been shown to provide significant psychological and physical benefits to people with lung disease and diseases of the respiratory muscles and chest wall. The authors document the effects of asthma, CF, and neuromuscular diseases on aerobic exercise to prevent unnecessary limitations on participation due to inaccurate preconceived notions of sports of exercise capacity in chronically ill adolescents.