A test-retest design was used.
To assess interexaminer reliability of the McKenzie method for performing clinical tests and classifying patients with low back pain.
Clinical methods and tests ...classifying patients with nonspecific low back pain have been based mainly on symptom duration or extent of pain referral. The McKenzie mechanical diagnostic and classification approach is a widely used noninvasive, low-technology method of assessing patients with low back pain. However, little is known about the interexaminer reliability of the method, previous studies having yielded conflicting results.
For this study, 39 volunteers with low back pain, mean age 40 years (range, 24-55 years), were blindly assessed by two physical therapists trained in the McKenzie method. The variability of two examiners for binary decisions was expressed by the kappa coefficient, and by the proportion of observed agreement, as calculated from a 2 x 2 contingency table of concordance.
On the basis of pure observation alone, agreement among clinical tests on the presence and direction of lateral shift was 77% (kappa = 0.2; P < 0.248) and 79% (kappa = 0.4; P < 0.003), respectively. Agreement on the relevance of lateral shift and the lateral component according to symptom responses was 85% (kappa = 0.7; P < 0.000) and 92% (kappa= 0.4; P < 0.021), respectively. Using the repeated movements and static end-range loading strategy to define the centralization phenomenon and directional preference, agreement was 95% (kappa = 0.7; P < 0.002) and 90% (kappa = 0.9; P < 0.000), respectively. When patients with low back pain were classified into the McKenzie main syndromes and into specific subgroups, agreement was 95% (kappa = 0.6; P < 0.000) and 74% (kappa = 0.7; P < 0.000), respectively.
Interexaminer reliability of the McKenzie lumbar spine assessment in performing clinical tests and classifying patients with low back pain into syndromes were good and statistically significant when the examiners had been trained in the McKenzie method.
High physical activity/aerobic fitness predicts low morbidity and mortality. Our aim was to identify the most up-regulated gene sets related to long-term physical activity vs. inactivity in skeletal ...muscle and adipose tissues and to obtain further information about their link with cardio-metabolic risk factors. We studied ten same-sex twin pairs (age range 50-74 years) who had been discordant for leisure-time physical activity for 30 years. The examinations included biopsies from m. vastus lateralis and abdominal subcutaneous adipose tissue. RNA was analyzed with the genome-wide Illumina Human WG-6 v3.0 Expression BeadChip. For pathway analysis we used Gene Set Enrichment Analysis utilizing active vs. inactive co-twin gene expression ratios. Our findings showed that among the physically active members of twin pairs, as compared to their inactive co-twins, gene expression in the muscle tissue samples was chronically up-regulated for the central pathways related to energy metabolism, including oxidative phosphorylation, lipid metabolism and supportive metabolic pathways. Up-regulation of these pathways was associated in particular with aerobic fitness and high HDL cholesterol levels. In fat tissue we found physical activity-associated increases in the expression of polyunsaturated fatty acid metabolism and branched-chain amino acid degradation gene sets both of which associated with decreased 'high-risk' ectopic body fat and plasma glucose levels. Consistent with other findings, plasma lipidomics analysis showed up-regulation of the triacylglycerols containing the polyunsaturated fatty acids. Our findings identified skeletal muscle and fat tissue pathways which are associated with the long-term physical activity and reduced cardio-metabolic disease risk, including increased aerobic fitness. In particular, improved skeletal muscle oxidative energy and lipid metabolism as well as changes in adipocyte function and redistribution of body fat are associated with reduced cardio-metabolic risk.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role ...of aerobic capacity, aging, and their interaction on metabolism, we utilized rat models selectively bred for low and high intrinsic aerobic capacity (LCRs/HCRs) and compared the metabolomics of serum, muscle, and white adipose tissue (WAT) at two time points: Young rats were sacrificed at 9 months of age, and old rats were sacrificed at 21 months of age. Targeted and semi-quantitative metabolomics analysis was performed on the ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS) platform. The effects of aerobic capacity, aging, and their interaction were studied via regression analysis. Our results showed that high aerobic capacity is associated with an accumulation of isovalerylcarnitine in muscle and serum at rest, which is likely due to more efficient leucine catabolism in muscle. With aging, several amino acids were downregulated in muscle, indicating more efficient amino acid metabolism, whereas in WAT less efficient amino acid metabolism and decreased mitochondrial β-oxidation were observed. Our results further revealed that high aerobic capacity and aging interactively affect lipid metabolism in muscle and WAT, possibly combating unfavorable aging-related changes in whole body metabolism. Our results highlight the significant role of WAT metabolism for healthy aging.
1 Neuromuscular Research Center and Department of Biology of
Physical Activity, University of Jyväskylä, 40351 Jyväskylä; 2 Department of Clinical Chemistry,
University of Oulu, 90220 Oulu, ...Finland; 3 The Human
Performance Laboratory, Ball State University, Muncie, Indiana 47306;
4 Department of Physical Medicine and Rehabilitation, Central
Hospital, 40620 Jyväskylä; 5 Department of Health
Sciences, University of Jyväskylä, 40351 Jyväskylä; and 6 Department of Physical Medicine and
Rehabilitation, Kuopio University Hospital, 70211 Kuopio,
Finland
Effects of strength training (ST) for 21 wk were
examined in 10 older women (64 ± 3 yr). Electromyogram, maximal
isometric force, one-repetition maximum strength, and rate of force
development of the leg extensors, muscle cross-sectional area (CSA) of
the quadriceps femoris (QF) and of vastus lateralis (VL), medialis (VM), intermedius (VI) and rectus femoris (RF) throughout the lengths
of 3/12-12/15 (Lf) of the femur, muscle fiber proportion and areas
of types I, IIa, and IIb of the VL were evaluated. Serum hormone
concentrations of testosterone, growth hormone (GH), cortisol, and
IGF-I were analyzed for the resting, preexercise, and postexercise conditions. After the 21-wk ST, maximal force increased by 37% ( P < 0.001) and 1-RM by 29% ( P < 0.001), accompanied by an increase ( P < 0.01) in rate
of force development. The integrated electromyograms of the vastus
muscles increased ( P < 0.05). The CSA of the total QF
increased ( P < 0.05) throughout the length of the
femur by 5-9%. The increases were significant ( P < 0.05) at 7/15-12/15 Lf for VL and at 3/15-8/15 Lf for VM,
at 5/15-9/15 for VI and at 9/15 ( P < 0.05) for
RF. The fiber areas of type I ( P < 0.05), IIa
( P < 0.001), and IIb ( P < 0.001)
increased by 22-36%. No changes occurred during ST in serum basal
concentrations of the hormones examined, but the level of testosterone
correlated with the changes in the CSA of the QF ( r = 0.64, P < 0.05). An acute increase of GH
( P < 0.05), remaining elevated up to 30 min
( P < 0.05) postloading, was observed only at
posttraining. Both neural adaptations and the capacity of skeletal
muscle to undergo training-induced hypertrophy even in older women
explain the strength gains. The increases in the CSA of the QF occurred
throughout its length but differed selectively between the individual
muscles. The serum concentrations of hormones remained unaltered, but a
low level of testosterone may be a limiting factor in training-induced
muscle hypertrophy. The magnitude and time duration of the acute GH
response may be important physiological indicators of anabolic
adaptations during strength training even in older women.
aging; muscle; endocrine functions; resistance training; selective
hypertrophy; electromyogram
1 Department of Health Sciences, 3 The Finnish Centre for Interdisciplinary Gerontology, and 7 Department of Psychology, University of Jyväskylä, FIN-40014 Jyväskylä; 2 Peurunka Medical ...Rehabilitation Center, FIN-41340 Laukaa; 4 Department of Public Health, University of Helsinki, FIN-00014 Helsinki; 5 Department of Mental Health, National Public Health Institute, FIN-00300 Helsinki; and 6 Department of Public Health, University of Turku, FIN-20014 Turku, Finland
Submitted 26 February 2003
; accepted in final form 3 September 2003
The purpose of the present study was to examine genetic and environmental effects on maximal isometric handgrip, knee extension, and ankle plantar flexion strength. In addition, we wanted to investigate whether the strength of these three muscle groups shares a genetic component or whether the genetic effect is specific for each muscle group. Muscle strength was measured as part of the Finnish Twin Study on Aging in 97 monozygotic (MZ) and 102 dizygotic (DZ) female twin pairs, aged 63-76 yr. The MZ and DZ individuals did not differ from each other in age, body height, weight, or self-related health. The age-adjusted pairwise (intraclass) correlations of the MZ and DZ twins were, respectively, 0.462 and 0.242 in knee extension, 0.435 and 0.345 in handgrip, and 0.512 and 0.435 in ankle plantar flexion strength. The multivariate genetic analysis showed that handgrip and knee extension strength shared a genetic component, which accounted for 14% (95% confidence interval: 4-28%) of the variance in handgrip strength and 31% (95% confidence interval: 18-45%) in knee extension strength. The influence of genetic effects on ankle plantar flexion strength was minor and not significant. Furthermore, these three muscle groups had a nongenetic familial effect in common and nonshared environmental effects in common. The results suggested that muscle strength is under a genetic regulation, but also environmental effects have a significant role in explaining the variability in the muscle strength.
aging; genetic; muscle force; twin study; women
Address for reprint requests and other correspondence: K. Tiainen, Dept. of Health Sciences, Univ. of Jyväskylä, P.O. Box 35 (Viveca), Univ. of Jyväskylä, FIN-40014 Jyväskylä, Finland (E-mail: tiainen{at}sport.jyu.fi ).
Background： The aim of this study was to compare 6 weeks short-term moderate intensity aerobic exercise and dieting on serum metabolomics and cardio-metabolic risk factors in pre-menopausal women. ...Methods： Ninety previously inactive overweight and obese （BMI 25-35 kg/m2） women （age 41.5 ± 7.6 years） were randomized to either a 6-week Nordic walking exercise program （EX, n = 45） or dietary counseling group （DI, n = 45）. Body composition, serum glucose, insulin and lipids were measured. Serum low-molecular-weight metabolites and lipid constituents were analyzed by nuclear magnetic resonance spectroscopy. Measurements were done at baseline and 7 days after the last training session. Results： Six weeks aerobic exercise program yielded reductions in serum free fatty acids （-34.7%, 95% confidence interval （CI）, -50 to -18, p 〈 0.001）, glucose （-9.6%, 95%CI, -15 to -4, p 〈 0.001） and homeostasis model assessment of insulin resistance （HOMA-IR） （-28.7%, 95%CI, -48 to -10, p = 0.005） without changes in body weight or fat mass. Diet counseling resulted in loss of body weight （1.5%, 95%CI, -2.3 to -0.7, p = 0.001） but no changes in free fatty acids, fasting glucose, or HOMA-IR were found. Conclusion： Our results indicate that small weight loss does not produce measurable health benefits, whereas short-term regular aerobic exercise can improve glucose and lipid metabolism even in the absence of weight loss in previously sedentary overweight and obese women.
Vitamin D is well known for its regulatory role in calcium and phosphate homeostasis, but its role in muscle mass and strength during growth remains inconclusive. We explored the association of serum ...25-hydroxyvitamin D (25(OH)D) with muscle development in girls from 11 to 18-years old. Whole body lean tissue mass (LMWB), appendicular lean mass (aLM), muscle cross-sectional area at the lower leg (mCSA), maximal voluntary contraction of elbow flexors (MVC elbow) and knee extensors (MVC knee) were assessed in 217 girls aged 10-13 years (at baseline), 215 in 2-year and 226 in 7.5-year follow-up. Serum concentration of 25(OH)D and intact parathyroid hormone (PTH) were analyzed retrospectively and girls were categorized according to their 25(OH)D levels (consistently insufficient 25(OH)D GLL <50 nmol/l and consistently sufficient GHH >50 nmol/l from baseline to 7-year follow-up). We found that 25(OH)D level declined until menarche (p<0.05) while LMWB, aLM, mCSA, MVC elbow and MVC knee continued to increase (p<0.001 for all) post menarche. At pre-menarche, the GLL (n = 34) had higher LMWB and aLM than the GHH (n = 21, p<0.05), while post-menarche the GHH (n = 15) had a greater catch-up gain in LMWB (p = 0.004), aLM (p = 0.001) and mCSA (p = 0.027) compared to the GLL (n = 65) over the first 2-year period. At the age of 18, no differences in muscle mass/strength between the low (n = 151) and high (n = 77) levels of 25(OH)D groups were found. This finding was independent of vitamin D receptor genotype and other confounders. In conclusion, our results showed that levels of 25(OH)D have no significant negative influence on the development of muscle mass and strength during pubertal growth both with longitudinal and cross-sectional comparison. On the contrary, our results suggest that the temporary negative association between 25(OH)D and muscle mass arises as a consequence of fast growth prior to menarche, and this negative association is diminished through catch-up growth after menarche.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Progressive strength training can lead to substantial increases in maximal strength and mass of trained muscles, even in older women and men, but little information is available about the effects of ...strength training on functional capabilities and balance. Thus, the effects of 21 weeks of heavy resistance training—including lower loads performed with high movement velocities—twice a week on isometric maximal force (ISOmax) and force-time curve (force produced in 500 milliseconds, F0–500) and dynamic 1 repetition maximum (1RM) strength of the leg extensors, 10-m walking time (10WALK) and dynamic balance test (DYN.D) were investigated in 26 middle-aged (MI; 52.8 ± 2.4 years) and 22 older women (O; 63.8 ± 3.8 years). 1RM, ISOmax, and F0-500 increased significantly in MI by 28 ± 10%, 20 ± 19%, 31 ± 34%, and in O by 27 ± 8%, 20 ± 16%, 18 ± 45%, respectively. 10WALK (MI and O, p < 0.001) shortened and DYN.D improved (MI and O, p < 0.001). The present strength-training protocol led to large increases in maximal and explosive strength characteristics of leg extensors and in walking speed, as well to an improvement in the present dynamic balance test performance in both age groups. Although training-induced increase in explosive strength is an important factor for aging women, there are other factors that contribute to improvements in dynamic balance capacity. This study indicates that total body heavy resistance training, including explosive dynamic training, may be applied in rehabilitation or preventive exercise protocols in aging women to improve dynamic balance capabilities.
Abstract Portegijs E, Kallinen M, Rantanen T, Heinonen A, Sihvonen S, Alen M, Kiviranta I, Sipilä S. Effects of resistance training on lower-extremity impairments in older people with hip fracture. ...Objective To study the effects of resistance training on muscle strength parameters, mobility, and balance. Design Randomized controlled trial. Setting Research laboratory and senior gym. Participants Population-based sample of eligible 60- to 85-year-old community-dwelling men and women 0.5 to 7.0 years after hip fracture. Forty-six people had no contraindications and were willing to participate in the exercise trial. Intervention Twelve-week intensive progressive strength-power training (n=24), aiming to reduce asymmetric deficit in leg muscle strength and power, or no intervention (n=22). Main Outcome Measures Isometric knee extension torque (KET) and leg extension power (LEP) measured in the weaker and stronger leg and the asymmetric deficit (weak/sum both legs × 100%), 10-m walking speed, dynamic balance test, and self-reported outdoor mobility. Results KET increased in both legs ( P <.021), LEP tended to increase in the weaker leg ( P =.071), and asymmetric LEP deficit decreased ( P =.010) after training compared with the control group. LEP of the stronger leg, asymmetric KET deficit, walking speed, and balance performance were not significantly affected by training. Self-reported ability to walk outdoors improved after training. The compliance to the training was over 90%, and few adverse events (n=4; mainly musculoskeletal) were likely to be caused by the training. Conclusions Intensive resistance training is feasible for people with a hip fracture and improved muscle strength and power. More intensive training especially for the weaker leg may be needed to obtain more marked effects on asymmetric deficit, mobility, and balance. Also, the timing and duration of training program should be considered. (ISRCTN identifier ISRCTN34271567.)
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