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Respiratory muscle strength but not BASFI score relates to diminished chest expansion in ankylosing spondylitis.

Pulmonary function is altered in ankylosing spondylitis (AS) owing mainly to the restriction of chest wall involvement (limited chest expansion). The objective of this study was to investigate the relationship between chest expansion, respiratory muscle strength (MIP, MEP) maximum voluntary ventilation (MVV), and BASFI score in patients with AS. Twenty-three male patients with definite AS and 21 age-matched healthy male controls were recruited for the study. Patients with AS were assessed for functional status by BASFI. Measurement of chest expansion and lumbar spinal flexion (modified Schober) method was performed in all subjects. Pulmonary function tests were performed by spirometry. Respiratory muscle strength was evaluated by a mouth-pressure meter (MPM). Body mass index (kg/m(2)) was recorded in all individuals. Chest expansion and modified Schober measurement were significantly lower in AS patients (p<0.05). Pulmonary function tests revealed restrictive lung disease. The mean BASFI score suggested good functional capacity in the AS group. The respiratory muscle strength and MVV were also lower in AS (p<0.05). The chest expansion was correlated with MIP and MEP values (r=0.491; p=0.02, r=0.436; p=0.05). Chest expansion was also correlated negatively with disease duration (r=-0.502; p=0.03). In addition, there was no correlation between chest expansion and BASFI score (r=-0.076; p=0.773). This study demonstrates that functional status (BASFI) is not influenced by the limitation of chest wall movement. It may be as a result of the maintenance of moderate physical activity during active life in patients with AS.

Health Status Indicators↗

Effects of lumbar belts on trunk muscle strength and endurance: a follow-up study of construction workers.

The effects on maximal isometric trunk muscle strength and endurance after wearing a soft heat-retaining lumbar belt or a weightlifter's belt were studied. The soft belt (SB) study group comprised 12 construction workers with healthy backs, and the weightlifter's belt (WB) group comprised 24 construction workers with current or previous low back pain. The strength and endurance measurements were performed before the start of belt use, and after 1 and 2 months. The SB group increased the trunk flexor strength by 13% (p less than or equal to 0.01) after 2 months. The WB group increased the trunk flexor strength and endurance by 12% and 29%, respectively (p less than or equal to 0.001). No significant decrease of trunk muscle strength and endurance was found at the end of the follow-up period.

Adult↗

Leisure time physical activity in the young. Correlation with low-back pain, spinal mobility and trunk muscle strength in 15-year-old school children.

From a population of 1503 school children, 38 15-year-old children reporting recurrent or continuous low-back pain (LBP) and 38 asymptomatic controls (34 boys and 42 girls) matched for age, sex and school class, were compared with respect to spinal mobility and trunk muscle strength. The subjects were interviewed on leisure time physical activity preceding the measurements. Of the subjects with recurrent or continuous LBP and of those completely without LBP experience 73.7% vs 42.1% reported that they pursued some physical activity two days a week or less (P = 0.006). Further, decreased spinal mobility, diminished endurance strength of the back muscles and diminished dynamic strength of the abdominal muscles were found in the group with a low frequency of activity. Mobility in children pursuing physical activity two days a week or less was decreased in lumbar extension measured by flexicurve, in forward bending, in side bending and in straight leg raising. Our results indicate that a very low frequency of physical activity in the young might be the risk factor for LBP. Pursuing sports as a leisure time activity is not harmful; on the contrary it has positive effects on spinal mobility and trunk muscle strength.

Abdominal Muscles↗

Respiratory muscle strength in Cushing's syndrome.

The effect of Cushing's syndrome on respiratory muscle strength is unknown. Therefore, we studied 10 consecutive patients with severe Cushing's syndrome. The respiratory muscles were assessed using maximal inspiratory and expiratory mouth pressures (MIP, MEP), maximal sniff transdiaphragmatic pressures (max sniff Pdi), and maximal sniff esophageal pressures (max sniff Pes). Maximal quadricep strength was also assessed. The patients demonstrated an overall mean MIP 92 cm H(2)O, SD 19 (mean 105% of predicted; SD, 23%), mean MEP 134 cm H(2)O, SD 35 (mean 99% of predicted; SD, 25%), mean max sniff Pdi 107 cm H(2)O, SD 12 (mean 78% of predicted; SD, 10%) and mean max sniff Pes of 92 cm H(2)O, SD 11 (mean 92% of predicted; SD, 11%). Quadriceps muscle strength was reduced in all 10 patients: mean 26 kg, SD 9 (mean 49% of predicted strength, SD 21%). Respiratory muscle weakness was not found, despite the presence of severe quadriceps impairment. We conclude that major weakness of the respiratory muscles is not usual in Cushing's syndrome.

Adult↗

Evaluation of pelvic floor muscle strength using four different techniques.

The aim of the study was to evaluate whether four different techniques were able to correctly measure pelvic floor muscle strength only. Sixteen volunteers performed a set of muscle contractions using the pelvic floor muscles (PFM) only, the abdominal muscles with and without PFM, gluteal muscles with and without PFM, adductor muscles with and without PFM and Valsalva maneuver with and without PFM. Pelvic floor muscle strength was evaluated by digital palpation, intravaginal EMG, pressure perineometry and perineal ultrasound. A 'non-pelvic muscle induced' reading was defined as a significant increase even though the pelvic floor muscles were not contracted. Results were as follows: isolated abdominal muscle contraction: non-pelvic muscle induced readings in 3/8 women with EMG and in 3/8 with pressure perineometry; isolated gluteal muscle contraction: non-pelvic muscle induced readings in 1/2 women with EMG perineometry; isolated adductor muscle contraction: non-pelvic muscle induced readings in 6/11 women with EMG perineometry and in 2/11 women with pressure perineometry; Valsalva maneuver: non-pelvic muscle induced readings in 4/9 women with EMG perineometry and 9/9 women with pressure perineometry. It was concluded that EMG and pressure perineometry do not selectively depict pelvic floor muscle activity.

Abdomen↗

Long-term follow-up of symptoms, pulmonary function, respiratory muscle strength, and exercise performance after botulism.

Respiratory muscle weakness occurs commonly at presentation in patients with botulism. Although clinical improvement occurs over several months, symptoms such as fatigue and dyspnea persist in many patients in the long term. To determine whether continued respiratory muscle weakness might contribute to these symptoms, we compared lung function tests, respiratory muscle strength, and exercise performance in 13 patients 2 years after type B botulism. We found that residual symptoms including dyspnea and fatigue were common in botulism patients at 2 years postintoxication. Lung function tests had returned to normal in all patients. Maximal inspiratory and expiratory pressures were similar between botulism patients and control subjects. Evaluation of individual results showed evidence of inspiratory muscle weakness in four of 13 patients with botulism (Plmax less than 65% predicted). Maximal oxygen consumption and maximal workload during exercise were reduced in botulism patients in comparison to control subjects. During exercise, botulism patients had a more rapid and shallow breathing pattern and a higher dyspnea score at a given minute ventilation in comparison to control subjects. Reasons for premature exercise termination in botulism patients were multifactorial. Although respiratory muscle weakness may have been contributory in some patients, most appeared to be limited by reduced cardiovascular fitness, leg fatigue, or reduced motivation.

Adult↗

Relationship of muscle strength to potassium concentration in a hypokalaemic infant.

A nine-month infant, weighing 9.8 kg, presented with hypotonia secondary to acute hypokalaemia (1.0 mmol/l). Muscle strength improved as the serum potassium was increased. Muscle strength was assessed by the pressure generated inside a saline-filled endotracheal tube cuff during a grasp reflex. Potassium concentration and hand grip strength were related using a sigmoidal Emax model. Zero effect was assumed when the potassium concentration was zero. The Emax, EC50 and Hill coefficient values were determined by non-linear regression using the MKMODEL program. Parameter estimates (SE) were EC50 1.79 (0.15) mmol/l, Hill coefficient 3.79 (0.92), Emax 114.4 (8.9) mmHg.

Acute Disease↗

The effect of habitual physical activity, non-athletic exercise, muscle strength, and VO2max on bone mineral density is rather low in early postmenopausal osteopenic women.

CONTEXT: Although the positive effect of well-designed exercise regimes on bone mineral density (BMD) is established the osteo-anabolic relevance of habitual physical activity and non-athletic exercise is still under discussion. OBJECTIVE: To determine the effects of habitual physical activity, non-athletic exercise muscle strength, VO2max and anthropometric parameters on BMD in early post-menopausal women. DESIGN: Cross-sectional study. METHODS: 150 early postmenopausal women (55.5+/-3.4 years), which were free of diseases or medication affecting bone metabolism and had no athletic history were investigated. The influence of weight, body composition, physical activity, isometric strength, VO2max, and nutritional intake on BMD was measured at multiple sites using different techniques. Further bone markers (Osteocalcin, CTX) were determined. Activity and weight-bearing activity were assessed by questionnaire. Maximum strength was measured isometrically. Aerobic capacity was measured with an spirometric system in a stepwise treadmill test and dietary intake was monitored over 5 days. RESULTS: Slight relationships between physical activity, exercise, muscle strength and VO2max with bone parameters were determined by univariate analysis. After adjusting for confounding variables in a stepwise regression analysis, significant relationships with BMD measured at the hip or the spine could no longer be detected for physical activity, exercise, and physical fitness (strength indices, VO2max). The same was true for osteocalcin and CTX. Arm strength explained 4.5% of the variation of forearm BMD (DXA). At the calcaneal site, osteogenic exercise was significantly related to the quantitative ultrasound index (r2 = 0.27). CONCLUSION: The isolated effect of habitual physical activity, unspecific exercise participation, and muscle strength on bone parameters is rather low in (early-) postmenopausal women. CLINICAL RELEVANCE: Women at risk should take specific exercise programs into consideration rather than to increasing the amount of habitual physical activity.

Biomarkers↗

Lung volumes and respiratory muscle strength in adult patients with childhood- or adult-onset growth hormone deficiency: effect of 12 months' growth hormone replacement therapy.

We have described impairment of the respiratory function in adult patients with childhood-onset growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient before and after 6 and 12 months of recombinant GH treatment. Ten adults diagnosed as GH deficient in childhood, ten adults diagnosed as GH deficient in adulthood and ten healthy subjects entered the study. For each subject, evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, record of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Childhood-onset GH-deficient patients had a significant reduction of maximal inspiratory (p < 0.01) and maximal expiratory (p < 0.05) mouth pressures. Total lung capacity, vital capacity and functional residual capacity were significantly reduced compared to healthy subjects (p < 0.05). Conversely, residual volume and diffusing lung capacity did not show any significant change. No significant change of the ratio between the percentage forced expiratory volume in 1 s and the forced vital capacity was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. Adult-onset GH-deficient patients had only a significant reduction of maximal expiratory pressure compared to healthy subjects (p < 0.05). After 6 months of treatment no significant differences in any of the evaluated parameters were found. After 12 months of treatment patients with childhood-onset GH deficiency show a significant improvement of lung volumes (p < 0.01) and maximal respiratory mouth pressures (p < 0.005), whereas adult-onset GH-deficient patients show a significant improvement of maximal expiratory pressure (p < 0.05). In conclusion, the results of this study showed that adult patients affected with childhood-onset GH deficiency suffer from an impairment of the ventilatory function due to a reduction of lung volumes and a decrease of respiratory pressures probably due to a reduction of respiratory muscle strength. This impairment was reversed after 12 months of treatment with recombinant GH. Conversely, adult-onset GH-deficient patients had only an impairment of the maximal expiratory pressure, probably due to respiratory muscle weakness re-established after 12 months of GH therapy.

Adult↗

Relationship between respiratory muscle strength, nutritional status, and lung volume in cystic fibrosis and asthma.

We measured static inspiratory and expiratory pressures (PImax and PEmax) in 29 patients with asthma for comparison with a previously reported group of 25 patients with cystic fibrosis (CF) and 80 normal control subjects. The purpose of the study was to assess the relationship between respiratory muscle strength, nutritional status, lung volumes, and training effect of the increased work of breathing in patients with chronic air-flow limitation. PEmax was similar in the asthma group, CF group, and normal control subjects despite a significant degree of malnutrition in the CF group (mean body mass percentile (BMP), 78 versus 107% in the asthma group, p less than 0.001). There was no correlation between BMP and PImax or PEmax in either study group. PImax, when corrected for lung volume, was greater than age- and sex-matched control values in 24% of the patients with CF and 48% of the patients with asthma. We conclude that respiratory muscle strength is not related to nutritional status (as measured by BMP) in patients with CF and asthma. Above-normal inspiratory muscle strength may result from a training effect of the increased work of breathing in both CF and asthma, regardless of nutritional status.

Adolescent↗

Association of the type I collagen alpha1 Sp1 polymorphism, bone density and upper limb muscle strength in community-dwelling elderly men.

A polymorphic binding site of the Sp1 transcription factor in the gene encoding the alpha1 chain of type I collagen is associated with bone mineral density (BMD) and, independently, with fracture risk in postmenopausal women. The aim of this study is to examine whether in community-dwelling men over age 70 years, the COL1A1 Sp1 polymorphism is associated with BMD (by dual-energy X-ray absorptiometry) and/or with bone turnover and muscle strength--factors related to both BMD and fracture risk. The COL1A1 Sp1 genotype (SS, Ss and ss) was determined using polymerase chain reaction and MscI restriction digestion. Presence of the s allele was significantly associated with lower BMD at the distal forearm (p = 0.03) and different distal radius subregions, with Z-score differences between extreme genotype groups (SS vs ss) ranging from 0.87 (ultradistal radius; p = 0.17) to 1.31 (mid-region of distal radius; p = 0.03). Presence of the s allele was also associated with lower BMD at the hip, with differences between genotypes not approaching statistical significance. There were no differences between genotype groups for any of the assessed markers of bone formation and resorption. Presence of the s allele was associated with lower grip (p = 0.03) and biceps strength (p = 0.04) at the dominant arm, with the difference between extreme genotype groups amounting to 21% and 30%, respectively. In a multivariate analysis, the association between COL1A1 Sp1 polymorphism and forearm BMD Z-score was no longer significant after adjustment for height, percentage lean mass, level of physical activity and upper limb strength (p = 0.18), whereas the genotype-specific difference for grip and biceps strength remained significant after adjustment for age, height and percentage lean mass (p = 0.04 and p= 0.05, respectively). In conclusion, the COL1A1 Sp1 polymorphism is associated with BMD at the forearm and upper limb muscle strength in elderly men, the findings of multivariate analyses suggesting that the genotype-specific differences for BMD might be mediated, at least in part, by differences in muscle strength.

Aged↗

[Physical working capacity and muscle strength in chronic renal failure are improved by exercise].

Patients with chronic kidney disease (CKD) show a decline in maximal exercise capacity and muscle strength as renal function decreases. Renal anaemia, skeletal muscle dysfunction, tiredness and increasing inactivity are the major causes of this deterioration. Exercise training improves maximal exercise capacity, muscle strength and endurance in young, middle-aged and elderly patients at all stages of CKD. Preferably exercise training should be started during the predialysis stage, however, it is equally effective in dialysis patients and after renal transplantation. It has a positive effect on muscle catabolism and counteracts weight loss and malnutrition. Moreover, exercise training has positive effects on functional capacity and health related quality of life. Exercise training should be prescribed by a neph-rologist and administered by a trained nephrological physiotherapist. Exercise training is an integral part of care of the CKD patient. It not only reduces suffering but also costs, resulting in major potential benefits for the patient, the health care system and society.

Exercise↗

Measuring muscle strength.

A dynamometer that can be held in the hand and that was designed to measure muscle strength in a simple way in the range 2-5 of the MRC scale, was tested in order to establish to what extent differences in results can be attributed to the observer, the subject and replication. Observers learned the technique quickly and their results agreed with each other to a considerable extent. The subjects showed a small learning effect in three of the four muscles tested. Normal muscle strength was measured in one hundred 18-year-old men.

Adult↗

Comparison of three methods of assessing muscle strength and imbalance ratios of the knee.

Three strength measurement methods for determining muscle strength and imbalance ratios of the knee were compared in 41 (23 female, 18 male) NCAA Division I track and field athletes. Peak quadriceps extensions and hamstring flexions were measured isotonically, isometrically, and isokinetically. Isokinetic measurements were performed on a Cybex II at 60 degrees /s. Isometric extension and flexion measurements were performed using the Nicholas Manual Muscle Tester (Lafayette Instruments; Lafayette, Ind). Isotonic measurements were done on both Universal and Nautilus apparatuses. Testing order was randomized to avoid a treatment order effect. A repeated measures ANOVA and a post hoc Tukey test were used to compare the three methods of assessing strength and imbalance ratios of the knee. Absolute strength values were significantly different according to gender and mode of testing. Bilateral strength imbalance ratios for knee flexion were significantly lower for the Nautilus leg curl machine. Ipsilateral strength imbalance ratios were significantly greater for the Cybex II. Our results indicated that absolute strength values cannot be interchanged between testing modes. Except for Cybex II (ipsilateral) and Nautilus (bilateral knee flexion), strength imbalance ratios could be interchanged.

Journal Article↗

Effect of cigarette smoking on muscle strength of flexibility of athletes.

Kraus-Webber test which indicates muscle strength and flexibility of certain group of muscles showed significant decrease in cigarette smoking athletes in the age group of 19-30 years compared to nonsmoking athletes. The results indicate tobacco smoke inhalation affects muscle flexibility and strength required for athletes.

Adult↗

Muscle strength in knee varus and valgus.

PURPOSE: The purpose of this study was to investigate the lower-limb muscle strength in knee varus-valgus and its dependence on knee varus-valgus position. The hypothesis was that humans could differentially contract the medial and lateral muscles crossing the knee and generate significant moments in knee valgus-varus. METHODS: The subjects sat with the knee at full extension and secured from the medial, lateral, anterior, and posterior sides. Both hips were clamped from the lateral sides. The subjects adducted (abducted) the ipsilateral hip during the knee valgus (varus) maximal voluntary contraction with EMG signals recorded from muscles crossing the knee and knee joint moments measured using a six-axis force sensor. Frontal plane tibiofemoral movement was evaluated using a fluoroscope. RESULTS AND CONCLUSIONS: The subjects differentially contracted the medial and lateral muscles, and fluoroscope images showed the corresponding tibiofemoral movement. The subjects showed considerable strength in knee varus and valgus. The active knee varus strength increased significantly with increasing knee valgus angle, and the valgus strength was significantly higher when the knee was in varus position (P < 0.039). Active valgus muscle strength at 5 degrees knee varus was significantly higher than the active varus strength at 5 degrees valgus (P = 0.002). The passive resistance moment increased linearly with increasing knee valgus and varus angles, and it accounted for 28% and 35% of the total (active plus passive) moment at the 5 degrees varus and 5 degrees valgus, respectively. The significant varus-valgus muscle strength demonstrated in this study may play important roles in performing various functional tasks, maintaining joint stability, and preventing potential injuries, whether the major load and motion at the knee is in the frontal plane or not.

Adult↗

Effects of warming up, massage, and stretching on range of motion and muscle strength in the lower extremity.

The effects of general warming up, massage, and stretching on ranges of motion (ROM) and strength of quadriceps and hamstring muscles were measured in eight male volunteers. Thigh muscle strength was not influenced by the experimental procedures. Stretching resulted in a significantly increased range of hip flexion/extension, hip abduction, knee flexion, and ankle dorsiflexion; the effect was significantly greater than that obtained by massage and warming up separately or combined. Only ankle dorsiflexion was influenced by massage or warming up, whereas stretching affected all muscle groups tested. Stretching was, therefore, superior to the other methods tested for increasing flexibility in the lower extremity.

Biomechanical Phenomena↗

Balance disorder and increased risk of falls in osteoporosis and kyphosis: significance of kyphotic posture and muscle strength.

This controlled trial was designed to investigate the influence of osteoporosis-related kyphosis (O-K) on falls. Twelve community-dwelling women with O-K (Cobb angle, 50-65 degrees measured from spine radiographs) and 13 healthy women serving as controls were enrolled. Mean age of the O-K group was 76 years (+/-5.1), height 158 cm (+/-5), and weight 61 kg (+/-7.9), and mean age of the control group was 71 years (+/-4.6), height 161 cm (+/-3.8), and weight 66 kg (+/-11.7). Quantitative isometric strength data were collected. Gait was monitored during unobstructed level walking and during stepping over an obstacle of four different heights randomly assigned (2.5%, 5%, 10%, and 15% of the subject's height). Balance was objectively assessed with computerized dynamic posturography consisting of the sensory organization test. Back extensor strength, grip strength, and all lower extremity muscle groups were significantly weaker in the O-K group than the control group (P <0.05), except right ankle plantar flexors (P =0.09). There was a significant difference in the anteroposterior and mediolateral displacements and velocities. The O-K subjects had less anteroposterior displacement, greater mediolateral displacement, reduced anteroposterior velocity, and increased mediolateral velocity compared with controls for all conditions of unobstructed and obstructed level walking. Obstacle height had a significant effect on all center-of-mass variables. The O-K subjects had significantly greater balance abnormalities on computerized dynamic posturography than the control group (P =0.002). Data show that thoracic hyperkyphosis on a background of reduced muscle strength plays an important role in increasing body sway, gait unsteadiness, and risk of falls in osteoporosis.

Accidental Falls↗