Left-right differences in the proximal femur's strength of post-menopausal women: a multicentric finite element study.

UNLABELLED: The strength of both femurs was estimated in 198 post-menopausal women through subject-specific finite element models. Important random differences between contralateral femurs were found in a significant number of subjects, pointing to the usefulness of further studies to understand if strength-based classification of patients at risk of fracture can be affected by laterality issues. INTRODUCTION: Significant, although small, differences exist in mineral density and anatomy of contralateral proximal femurs. These differences, and their combined effect, may result in a side difference in femurs' strength. However, this has never been tested on a large sample of a homogenous population. METHODS: The strength of both femurs was estimated in 198 post-menopausal women through CT-derived finite element models, built using a validated procedure, in sideways fall conditions. The impact of the resulting asymmetry on the classification of subjects at risk of fracture was analysed. RESULTS: The small difference observed between sides (the right femur on average 4 % stronger than the left) was statistically significant but mechanically negligible. In contrast, higher random differences (absolute difference between sides with respect to mean value) were found: on average close to 15 % (compared to 9.2 % for areal bone mineral density (aBMD) alone), with high scatter among the subjects. When using a threshold-based classification, the right and left femurs were discordant up to over 20 % of cases (K always lower than 0.60) but the left femur was concordant (mean K = 0.84) with the minimum strength between right and left. CONCLUSION: Considering both femurs may be important when trying to classify subjects at risk of failure with strength estimates. Future studies including fracture assessment would be necessary to quantify the real impact.

Vertebral Scheuermann's disease in Europe: prevalence, geographic variation and radiological correlates in men and women aged 50 and over.

UNLABELLED: In 27 centres across Europe, the prevalence of deforming spinal Scheuermann's disease in age-stratified population-based samples of over 10,000 men and women aged 50+ averaged 8% in each sex, but was highly variable between centres. Low DXA BMD was un-associated with Scheuermann's, helping the differential diagnosis from osteoporosis. INTRODUCTION: This study aims to assess the prevalence of Scheuermann's disease of the spine across Europe in men and women over 50 years of age, to quantitate its association with bone mineral density (BMD) and to assess its role as a confounder for the radiographic diagnosis of osteoporotic fracture. METHODS: In 27 centres participating in the population-based European Vertebral Osteoporosis Study (EVOS), standardised lateral radiographs of the lumbar and of the thoracic spine from T4 to L4 were assessed in all those of adequate quality. The presence of Scheuermann's disease, a confounder for prevalent fracture in later life, was defined by the presence of at least one Schmorl's node or irregular endplate together with kyphosis (sagittal Cobb angle >40° between T4 and T12) or a wedged-shaped vertebral body. Alternatively, the (rare) Edgren-Vaino sign was taken as diagnostic. The 6-point-per-vertebral-body (13 vertebrae) method was used to assess osteoporotic vertebral shape and fracture caseness. DXA BMD of the L2-L4 and femoral neck regions was measured in subsets. We also assessed the presence of Scheuermann's by alternative published algorithms when these used the radiographic signs we assessed. RESULTS: Vertebral radiographic images from 4486 men and 5655 women passed all quality checks. Prevalence of Scheuermann's varied considerably between centres, and based on random effect modelling, the overall European prevalence using our method was 8% with no significant difference between sexes. The highest prevalences were seen in Germany, Sweden, the UK and France and low prevalences were seen in Hungary, Poland and Slovakia. Centre-level prevalences in men and women were highly correlated. Scheuermann's was not associated with BMD of the spine or hip. CONCLUSIONS: Since most of the variation in population impact of Scheuermann's was unaccounted for by the radiological and anthropometric data, the search for new genetic and environmental determinants of this disease is encouraged.

Mechanography performance tests and their association with sarcopenia, falls and impairment in the activities of daily living - a pilot cross-sectional study in 293 older adults.

OBJECTIVES: Muscle mass and muscle power considerably decline with aging. The aim of the present study was to determine the association between muscular function using mechanography and sarcopenia, falls and impairment in the activities of daily living (ADL) in a sample of 293 community-dwelling women and men aged 60-85 years in Berlin, Germany. METHODS: Muscle function was determined by muscle power per body mass in vertical countermovement jumps (2LJPrel) and the chair rising test (CRTPrel) on a force plate. Sarcopenia status was assessed by estimating appendicular muscle mass with dual-X-ray absorptiometry. Self-reported ADL impairment and falls in the last 12 months were determined. RESULTS: ADL impairment was significantly correlated with all performance tests but not with muscle mass. The 2LJPrel (OR 0.88, 95%-CI 0.79-0.98), the Esslinger Fitness Index (EFI) (OR 0.97, 95%-CI 0.94-1.00) and the maximal velocity of the CRT (OR 0.70, 95%-CI 0.53-0.93) remained significant correlates for sarcopenia independent of age in men but not in women. The EFI could differentiate female individuals who had past fall events (OR 0.96, 95%-CI 0.93-0.98). CONCLUSION: The results of the present study highlight the importance of assessing muscle power in older individuals as a relevant correlate for functional decline.

Loss and re-adaptation of lumbar intervertebral disc water signal intensity after prolonged bedrest.

The adaptation and re-adaptation process of the intervertebral disc (IVD) to prolonged bedrest is important for understanding IVD physiology and IVD herniations in astronauts. Little information is available on changes in IVD composition. In this study, 24 male subjects underwent 60-day bedrest and In/Out Phase magnetic resonance imaging sequences were performed to evaluate IVD shape and water signal intensity. Scanning was performed before bedrest (baseline), twice during bedrest, and three, six and twenty-four months after bedrest. Area, signal intensity, average height, and anteroposterior diameter of the lumbar L3/4 and L4/5 IVDs were measured. At the end of bedrest, disc height and area were significantly increased with no change in water signal intensity. After bedrest, we observed reduced IVD signal intensity three months (p=0.004 versus baseline), six months (p=0.003 versus baseline), but not twenty-four months (p=0.25 versus baseline) post-bedrest. At these same time points post-bedrest, IVD height and area remained increased. The reduced lumbar IVD water signal intensity in the first months after bedrest implies a reduction of glycosaminoglycans and/or free water in the IVD. Subsequently, at two years after bedrest, IVD hydration status returned towards pre-bedrest levels, suggesting a gradual, but slow, re-adaptation process of the IVD after prolonged bedrest.

Preferential deposition of visceral adipose tissue occurs due to physical inactivity.

We hypothesised that strict inactivity (bed rest) would lead to regional differences in fat deposition. Twenty-four male subjects underwent 60 d bed rest and remained inactive (n = 9), performed resistance exercise plus whole-body vibration (RVE; n = 7) or resistance exercise only (RE; n = 8). Fat mass was assessed via dual X-ray absorptiometry. In the inactive subjects, fat deposition differed between body regions (P = 0.0005) with android region visceral adipose tissue increasing the most (+29% at the end of bed rest), followed by remainder of the trunk (from chin to the iliac crest; +10%) and the arms and legs (both +7%). Insulin sensitivity reduced in the inactive subjects at the end of bed rest (P = 0.036). RE did not have a significant impact on regional fat mass changes (P ⩾ 0.055). In RVE, increases in visceral adipose tissue (-14%; P = 0.028 vs inactive subjects) and in the arms (arms -8%, P = 0.011 vs inactive) were not seen. We conclude that inactivity leads to a preferential increase in visceral adipose tissue.

TBS result is not affected by lumbar spine osteoarthritis.

UNLABELLED: The effect of lumbar osteoarthritis on bone density and trabecular bone score (TBS) was evaluated cross-sectionally and prospectively in postmenopausal women. Lumbar spine osteoarthritis was graded according to Kellgren and Lawrence grades. Lumbar osteoarthritis was found to increase lumbar spine bone density, but not TBS. INTRODUCTION: Lumbar osteoarthritis overestimates lumbar bone density (areal bone mineral density (aBMD)). A new texture parameter, the TBS, has been proposed. Calculation of aBMD uses grey level value, while TBS uses grey level variation. Therefore, our hypothesis was that TBS is not influenced by lumbar spine osteoarthritis. METHODS: Menopausal women participating in osteoporosis and ultrasound (OPUS) study were included. They had an aBMD measurement of the spine and hip at baseline and 6-year visit. TBS was calculated on lumbar spine dual-energy X-ray absorptiometry (DXA) scans in an automated manner. The presence of lumbar osteoarthritis was evaluated on baseline radiographs using Kellgren and Lawrence (K&L) classification. Grades range from 0 to 4. In our study, osteoarthritis was defined by at least K&L grade 2. RESULTS: This study included 1,254 menopausal women (66.7 ± 7.1 years). Among them, 727 attended the 6-year follow-up visit. Patients with lumbar osteoarthritis had an aBMD higher than those without lumbar osteoarthritis at the lumbar spine, but not at the hip. However, the aBMD significantly increased in all sites with the grade of K&L. In contrast, spine TBS was not different between patients with and without lumbar osteoarthritis (p = 0.70), and it was not correlated with K&L grade. Spine TBS and aBMD at all sites were negatively correlated with age (p < 0.0001). Body mass index was correlated positively with aBMD and negatively with spine TBS (p < 0.0001). The 6-year change of aBMD was significant in the hip and nonsignificant in the lumbar spine. That of TBS was significant, with a 3.3 % decrease (p < 0.0001), independent of K&L grade (p = 0.28). CONCLUSION: In postmenopausal women, lumbar osteoarthritis leads to an increase in lumbar spine aBMD. In contrast, spine TBS is not affected by lumbar osteoarthritis.

Bone density and neuromuscular function in older competitive athletes depend on running distance.

UNLABELLED: Individuals who are involved in explosive sport types, such as 100-m sprints and long jump, have greater bone density, leg muscle size, jumping height and grip strength than individuals involved in long-distance running. INTRODUCTION: The purpose of this study is to examine the relationship between different types of physical activity with bone, lean mass and neuromuscular performance in older individuals. METHODS: We examined short- (n = 50), middle- (n = 19) and long-distance (n = 109) athletes at the 15th European Masters Championships in Poznan, Poland. Dual X-ray absorptiometry was used to measure areal bone mineral density (aBMD) and lean tissue mass. Maximal countermovement jump, multiple one-leg hopping and maximal grip force tests were performed. RESULTS: Short-distance athletes showed significantly higher aBMD at the legs, hip, lumbar spine and trunk compared to long-distance athletes (p ≤ 0.0012). Countermovement jump performance, hop force, grip force, leg lean mass and arm lean mass were greater in short-distance athletes (p ≤ 0.027). A similar pattern was seen in middle-distance athletes who typically showed higher aBMD and better neuromuscular performance than long-distance athletes, but lower in magnitude than short-distance athletes. In all athletes, aBMD was the same or higher than the expected age-adjusted population mean at the lumbar spine, hip and whole body. This effect was greater in the short- and middle-distance athletes. CONCLUSIONS: The stepwise relation between short-, middle- and long-distance athletes on bone suggests that the higher-impact loading protocols in short-distance disciplines are more effective in promoting aBMD. The regional effect on bone, with the differences between the groups being most marked at load-bearing regions (legs, hip, spine and trunk) rather than non-load-bearing regions, is further evidence in support of the idea that bone adaptation to exercise is dependent upon the local loading environment, rather than as part of a systemic effect.

Cross-sectional assessment of neuromuscular function using mechanography in women and men aged 20-85 years.

OBJECTIVES: The aim of this cross-sectional study was to examine the influence of age and sex on neuromuscular function of the lower limbs using mechanography. 704 adults aged 20-85 years from Germany participated in this study. METHODS: Ground reaction force and power were assessed with countermovement jumps and the chair rising test on a ground reactions force plate. RESULTS: While ground reaction force per unit body mass declined by about 20% from the third to the ninth decade, the decline of power per unit body mass was much greater, varying between 40-50%. Men and women are affected equally by the decline. Age and sex explained the variability of the power parameters to a much greater extent (R(2)=0.54 to R(2)=0.70) than the force parameters (R(2)=0.18 to R(2)=0.36). CONCLUSIONS: Our reference values can help to identify those who might be affected by the development of sarcopenia. Preventive exercise programs should focus on preserving muscle power in addition to the training of muscle force.

Bone strength and density via pQCT in post-menopausal osteopenic women after 9 months resistive exercise with whole body vibration or proprioceptive exercise.

OBJECTIVES: In order to better understand which training approaches are more effective for preventing bone loss in post-menopausal women with low bone mass, we examined the effect of a nine-month resistive exercise program with either an additional whole body vibration exercise (VIB) or balance training (BAL). METHODS: 68 post-menopausal women with osteopenia were recruited for the study and were randomised to either the VIB or BAL group. Two training sessions per week were performed. 57 subjects completed the study (VIB n=26; BAL n=31). Peripheral quantitative computed tomography (pQCT) measurements of the tibia, fibula, radius and ulna were performed at baseline and at the end of the intervention period at the epiphysis (4% site) and diaphysis (66% site). Analysis was done on an intent-to-treat approach. RESULTS: Significant increases in bone density and strength were seen at a number of measurement sites after the intervention period. No significant differences were seen in the response of the two groups at the lower-leg. CONCLUSIONS: This study provided evidence that a twice weekly resistive exercise program with either additional balance or vibration training could increase bone density at the distal tibia after a nine-month intervention period in post-menopausal women with low bone mass.

Comparing Prevalence of Sarcopenia Using Twelve Sarcopenia Definitions in a Large Multinational European Population of Community-Dwelling Older Adults.

OBJECTIVES: Multinational prevalence data on sarcopenia among generally healthy older adults is limited. The aim of the study was to assess prevalence of sarcopenia in the DO-HEALTH European trial based on twelve current sarcopenia definitions. SETTING AND PARTICIPANTS: This is an analysis of the DO-HEALTH study including 1495 of 2157 community-dwelling participants age 70+ years from Germany, France, Portugal, and Switzerland with complete measurements of the sarcopenia toolbox including muscle mass by DXA, grip strength, and gait speed. MEASUREMENTS: The twelve sarcopenia definitions applied were Asian Working Group on Sarcopenia (AWGS1), AWGS2, Baumgartner, Delmonico, European Working Group on Sarcopenia in Older People (EWGSOP1), EWGSOP2, EWGSOP2-lower extremities, Foundation for the National Institutes of Health (FNIH1), FNIH2, International Working Group on Sarcopenia in Older People (IWGS), Morley, and Sarcopenia Definitions and Outcomes Consortium (SDOC). RESULTS: Mean age was 74.9 years (SD 4.4); 63.3% were women. Sarcopenia prevalence ranged between 0.7% using the EWGSOP2 or AWGS2 definition, up to 16.8% using the Delmonico definition. Overall, most sarcopenia definitions, including Delmonico (16.8%), Baumgartner (12.8%), FNIH1(10.5%), IWGS (3.6%), EWGSOP1 (3.4%), SDOC (2.0%), Morley (1.3%), and AWGS1 (1.1%) tended to be higher than the prevalence based on EWGSOP2 (0.7%). In contrast, the definitions AWGS2 (0.7%), EWGSOP2-LE (1.1%), FNIH2 (1.0%) - all based on muscle mass and muscle strength - showed similar lower prevalence as EWGSOP2 (0.7%). Moreover, most sarcopenia definitions did not overlap on identifying sarcopenia on an individual participant-level. CONCLUSION: In this multinational European trial of community-dwelling older adults we found major discordances of sarcopenia prevalence both on a population- and on a participant- level between various sarcopenia definitions. Our findings suggest that the concept of sarcopenia may need to be rethought to reliably and validly identify people with impaired muscle health.

The effects of bed-rest and countermeasure exercise on the endocrine system in male adults: evidence for immobilization-induced reduction in sex hormone-binding globulin levels.

BACKGROUND AND AIM: There is limited data on the effects of inactivity (prolonged bed-rest) on parameters of endocrine and metabolic function; we therefore aimed to examine changes in these systems during and after prolonged (56- day) bed-rest in male adults. SUBJECTS AND METHODS: Twenty healthy male subjects underwent 8 weeks of strict bed-rest and 12 months of follow-up as part of the Berlin Bed Rest Study. Subjects were randomized to an inactive group or a group that performed resistive vibration exercise (RVE) during bed-rest. All outcome parameters were measured before, during and after bed-rest. These included body composition (by whole body dual X-ray absorptiometry), SHBG, testosterone (T), estradiol (E2), PRL, cortisol (C), TSH and free T3 (FT3). RESULTS: Serum SHBG levels decreased in inactive subjects but remained unchanged in the RVE group (p<0.001). Serum T concentrations increased during the first 3 weeks of bed-rest in both groups (p<0.0001), while E2 levels sharply rose with re-mobilization (p<0.0001). Serum PRL decreased in the control group but increased in the RVE group (p=0.021). C levels did not change over time (p≥0.10). TSH increased whilst FT3 decreased during bed-rest (p all ≤0.0013). CONCLUSIONS: Prolonged bed-rest has significant effects on parameters of endocrine and metabolic function, some of which are related to, or counteracted by physical activity.

Evidence for an additional effect of whole-body vibration above resistive exercise alone in preventing bone loss during prolonged bed rest.

SUMMARY: The addition of whole-body vibration to high-load resistive exercise may provide a better stimulus for the reduction of bone loss during prolonged bed rest (spaceflight simulation) than high-load resistive exercise alone. INTRODUCTION: Prior work suggests that the addition of whole-body vibration to high-load resistive exercise (RVE) may be more effective in preventing bone loss in spaceflight and its simulation (bed rest) than resistive exercise alone (RE), though this hypothesis has not been tested in humans. METHODS: Twenty-four male subjects as part of the 2nd Berlin Bed Rest Study performed RVE (n = 7), RE (n = 8) or no exercise (control, n = 9) during 60-day head-down tilt bed rest. Whole-body, spine and total hip dual X-ray absorptiometry (DXA) measurements as well as peripheral quantitative computed tomography measurements of the tibia were conducted during bed rest and up to 90 days afterwards. RESULTS: A better retention of bone mass in RVE than RE was seen at the tibial diaphysis and proximal femur (p ≤ 0.024). Compared to control, RVE retained bone mass at the distal tibia and DXA leg sub-region (p ≤ 0.020), but with no significant difference to RE (p ≥ 0.10). RE impacted significantly (p = 0.038) on DXA leg sub-region bone mass only. Calf muscle size was impacted similarly by both RVE and RE. On lumbar spine DXA, whole-body DXA and calcium excretion measures, few differences between the groups were observed. CONCLUSIONS: Whilst further countermeasure optimisation is required, the results provide evidence that (1) combining whole-body vibration and high-load resistance exercise may be more efficient than high-load resistive exercise alone in preventing bone loss at some skeletal sites during and after prolonged bed rest and (2) the effects of exercise during bed rest impact upon bone recovery up to 3 months afterwards.

Additive impact of alfacalcidol on bone mineral density and bone strength in alendronate treated postmenopausal women with reduced bone mass.

OBJECTIVES: Assessment of additive impact of alfacalcidol 1 µg daily (Alfa) on bone mineral density (BMD) and on bone strength in postmenopausal women treated with alendronate 70 mg weekly + 500 mg calcium daily. SUBJECTS AND METHODS: In a randomized, double-blind, placebo controlled study, 279 postmenopausal women with osteoporosis or osteopenia participated (intention to treat analysis [ITT]; aged 73.6∓4.7 years) and were treated with 70 mg alendronate (ALN) weekly and 500 mg calcium daily for 36 months. In addition, these patients received either 1 µg alfacalcidol (Alfa) or placebo (PLC) daily. BMD was measured with Dual-Energy-X-ray-Absorptiometry (DXA) at the lumbar spine and proximal femur and at forearm and tibia with peripheral quantitative computed tomography (pQCT) at regular intervals for 36 months. RESULTS: DXA-BMD of lumbar spine (L1-4) increased after 36 months, by 6.65% (p<0.0001) in the Alfa/ALN group versus 4.17% (p<0.0001) in the PLC/ALN group. Group difference was significant after 3 years (p=0.026). At the end of the study, significant differences were found in favor of the Alfa/ALN group in trabecular density (tibia) (p=0.002), cortical density (midshaft tibia) (p=0.043), and bone strength (p=0.001). The remaining parameters showed no differences between the treatment arms, apart cortical bone density at midshaft radius. CONCLUSIONS: Alfacalcidol significantly increases the efficacy of alendronate treatment in osteopenic/osteoporotic postmenopausal women on spinal DXA-BMD, cortical and trabecular BMD of the tibia and also bending stiffness of the tibia.

Does body height reduction influence interpretation of lung function in COPD patients?

Vertebral deformities are prevalent in chronic obstructive pulmonary disease (COPD) patients and may cause excessive loss of height. As height is used for calculating reference values for pulmonary function tests, larger than normal height reduction could cause overestimation of lung function. In this cross-sectional study of 465 COPD patients and 462 controls, we explored how often lung function is misinterpreted due to height reduction in COPD patients, and whether the number or severity of vertebral deformities correlate with height reduction. Measured height was compared to recalled tallest height (RTH) and height calculated from arm span (ASH) to assess height reduction. Vertebral deformities were assessed from radiographs and pulmonary function was assessed using standard formulae. Height reduction was frequent in both the study and control groups, and increased with the number and severity of vertebral deformities. When using current measured height, lung function was overestimated in a significant proportion of COPD patients at relatively modest height reductions. The effects were smallest for forced expiratory volume in 1 s and forced vital capacity, and most pronounced for total lung capacity and residual volume. Therefore, we propose that in COPD patients with excessive height reduction, one might use RTH or ASH in calculating predicted values. Furthermore, such patients should be evaluated for co-existing vertebral deformities and osteoporosis.

Resistive vibration exercise attenuates bone and muscle atrophy in 56 days of bed rest: biochemical markers of bone metabolism.

UNLABELLED: During and after prolonged bed rest, changes in bone metabolic markers occur within 3 days. Resistive vibration exercise during bed rest impedes bone loss and restricts increases in bone resorption markers whilst increasing bone formation. INTRODUCTION: To investigate the effectiveness of a resistive vibration exercise (RVE) countermeasure during prolonged bed rest using serum markers of bone metabolism and whole-body dual X-ray absorptiometry (DXA) as endpoints. METHODS: Twenty healthy male subjects underwent 8 weeks of bed rest with 12 months follow-up. Ten subjects performed RVE. Blood drawings and DXA measures were conducted regularly during and after bed rest. RESULTS: Bone resorption increased in the CTRL group with a less severe increase in the RVE group (p = 0.0004). Bone formation markers increased in the RVE group but decreased marginally in the CTRL group (p < 0.0001). At the end of bed rest, the CTRL group showed significant loss in leg bone mass (-1.8(0.9)%, p = 0.042) whereas the RVE group did not (-0.7(0.8)%, p = 0.405) although the difference between the groups was not significant (p = 0.12). CONCLUSIONS: The results suggest the countermeasure restricts increases in bone resorption, increased bone formation, and reduced bone loss during bed rest.

The 2nd Berlin BedRest Study: protocol and implementation.

Long-term bed-rest is used to simulate the effect of spaceflight on the human body and test different kinds of countermeasures. The 2nd Berlin BedRest Study (BBR2-2) tested the efficacy of whole-body vibration in addition to high-load resisitance exercise in preventing bone loss during bed-rest. Here we present the protocol of the study and discuss its implementation. Twenty-four male subjects underwent 60-days of six-degree head down tilt bed-rest and were randomised to an inactive control group (CTR), a high-load resistive exercise group (RE) or a high-load resistive exercise with whole-body vibration group (RVE). Subsequent to events in the course of the study (e.g. subject withdrawal), 9 subjects participated in the CTR-group, 7 in the RVE-group and 8 (7 beyond bed-rest day-30) in the RE-group. Fluid intake, urine output and axiallary temperature increased during bed-rest (p < .0001), though similarly in all groups (p > or = .17). Body weight changes differed between groups (p < .0001) with decreases in the CTR-group, marginal decreases in the RE-group and the RVE-group displaying significant decreases in body-weight beyond bed-rest day-51 only. In light of events and experiences of the current study, recommendations on various aspects of bed-rest methodology are also discussed.

High prevalence of vertebral deformities in COPD patients: relationship to disease severity.

Bone mineral density decreases with advancing chronic obstructive pulmonary disease (COPD) severity, but it is not known whether this is reflected in higher fracture rates. The present authors wanted to compare the prevalence of vertebral deformities in COPD patients with those in a population-based reference group to determine whether the number of deformities was related to the severity of COPD and how far the use of oral corticosteroids (OCS) influenced the prevalence of deformities. In the present cross-sectional study of 465 COPD patients and 462 controls, vertebral deformities were found in 31% of the COPD patients and 18% of the controls. In subjects who had never or sporadically used OCS, deformities were found in 29% of the COPD patients and 17% of the controls. In females, the average number of vertebral deformities was almost two-fold when COPD severity increased from Global Initiative of Chronic Obstructive Lung Disease stage II to III. In males, the use of OCS had a small but significant influence. Prevalence of vertebral deformities was significantly higher in chronic obstructive pulmonary disease patients than in the controls. In females, the average number of deformities was related to chronic obstructive pulmonary disease severity even after adjustment for other known risk factors. The difference between patients and controls remained significant even in those who never or sporadically used oral corticosteroids.

Resistive vibration exercise reduces lower limb muscle atrophy during 56-day bed-rest.

OBJECTIVES: The current study aimed to examine the effectiveness of a resistive vibration exercise countermeasure during prolonged bed-rest in preventing lower-limb muscle atrophy. METHODS: 20 male subjects underwent 56-days of bed-rest and were assigned to either an inactive control, or a countermeasure group which performed high-load resistive exercises (including squats, heel raises and toe raises) with whole-body vibration. Magnetic resonance imaging of the lower-limbs was performed at two-weekly intervals. Volume of individual muscles was calculated. RESULTS: Countermeasure exercise reduced atrophy in the triceps surae and the vastii muscles (F>3.0, p<.025). Atrophy of the peroneals, tibialis posterior and toe flexors was less in the countermeasure-subjects, though statistical evidence for this was weak (For=.071). Atrophy in the hamstring muscles was similar in both groups (F<1.1, p>.38). The adductor longus, sartiorius and rectus femoris muscles showed little loss of muscle volume during bed-rest (F<1.7, p>.15). CONCLUSIONS: The countermeasure exercise programme was effective in reducing atrophy in the extensors of the knee and ankle but not the hamstrings.

Whole body vibration in cystic fibrosis--a pilot study.

INTRODUCTION: In cystic fibrosis (CF), bone mass deficits as well as a lack of muscle mass and force have been described. The bone mass deficits are thought to be at least in part secondary to the reduced muscle mass. Whole body vibration has recently been suggested as an effective technique to increase muscle force and power. The aim of this pilot study was to evaluate the compliance and safety of a side-alternating, whole body vibration platform in patients with CF and to assess its effects on muscle force, muscle power, bone mass and lung function. PATIENTS AND METHODS: Eleven adult CF patients participated in a six-months home-based training programme on a whole body vibration platform. Muscle force and power were assessed with three standard manoeuvres on a ground reaction force plate at regular intervals. Bone densitometry was performed at the spine, the radius and the tibia using quantitative computerized tomography. RESULTS: Regular cardiovascular monitoring did not show any critical drop in oxygen saturation or blood pressure. Lung function remained relatively constant with a median FEV1 change [% of norm] of -3.1% (range -7-20). Trabecular density at the spine and parameters of bone density and geometry at the radius and tibia did not show consistent changes. A median decrease of -0.3% (-31.0-17.9) for muscle force and a median increase of 4.7% (-16.4-74.5) for muscle power and 6.6% (-0.9-48.3) for velocity was noted in the two-leg jump. In the one-leg jump, a median increase of 6.7% (-8.5-24.3) for muscle force was measured. CONCLUSIONS: Whole body vibration was well tolerated in the majority of the study participants. Most patients were able to increase peak force in the one-leg jump. In the two-leg jump, velocity and muscle power increased with equal or decreased muscle force. This may indicate an improvement in neuromuscular and intramuscular co-ordination (and therefore efficiency) with less muscle force necessary to generate the same power.