Muscle In Older Women Research Articles

Selected hallmarks of hallux valgus in older women with symptomatic hallux valgus compared to middle-aged women with and without deformation of the forefoot

The aim of the study was to compare the shape of the feet, the mobility of the metatarsophalangeal and interphalangeal joints and the flexibility of the calf muscles in older women with hallux valgus versus middle-aged women with and without this deformation to identify the presence of features which correlate particularly strongly with hallux valgus, and on which prophylaxis and conservative treatment should focus. The study involved 201 women: 92 aged 60–84 years with hallux valgus of both toes, 78 aged 38–59 with hallux valgus of both toes, and 31 aged 38–57 years with correctly shaped feet. The intensity of pain in the foot, the valgus angle of the big toe and fifth toe, the longitudinal and transverse arches of the foot, the symmetry of foot load with body weight, toe joint mobility and muscle flexibility were analysed. Both groups of women with hallux valgus differed from women with normal feet in the height of the transverse arch, the extent of dorsal extension in the first metatarsophalangeal joint and plantar flexion in the first interphalangeal joint. Older women were additionally characterised by reduced plantar flexion in the metatarsophalangeal joint of the big toe, limited flexibility of the soleus and gastrocnemius muscles as well as less pain in the toe area than in the foot itself. The most characteristic changes which were observed in older women with hallux valgus are a limited range of motion in the MTP and IP joints of the big toe, a reduced transverse arch and increased restriction of calf muscle flexibility.

Effects of 6-weeks of detraining on functional capacity and rapid torque production in older women

Mat Pilates has become an attractive alternative exercise among older women, however, despite knowing the importance of regular exercise, interrupting training is a common issue in this population. The aim of the current study was to evaluate the effects of 6-weeks of detraining after a period of 12-weeks of training with Mat Pilates on the functional capacity and neuromuscular performance of the knee extensor muscles in older women. Ten older women (62.6 ± 2.6 years; 1.57 ± 0.05 m height; 69.3 ± 9.2 kg; 27.8 kg/m2 body mass index) volunteered to participate in this study. The study was divided into three periods: a 4-week control period, followed by 12 weeks of Mat Pilates intervention, and a 6-week detraining period. During the intervention, the results showed significant improvements in functional capacity tests (time up and go, time up stairs, time down stairs, and chair sit-and-reach), rate of torque development, and impulse (p < 0.05). After the detraining period, a decrease was observed in the chair sit-and-reach test (p < 0.05) and contractile impulse at intervals 0–30 and 0–50 ms (p < 0.05). We conclude that a 6-week detraining period after a Mat Pilates training protocol was sufficient to cause declines in the chair sit-and-reach test and in the contractile impulse of the knee extensors in the early phase of the torque-time curve (0–30 and 0–50 ms), but not in the other functional capacity tests and neuromuscular parameters evaluated.

MRI-based anatomical characterisation of lower-limb muscles in older women.

The ability of muscles to produce force depends, among others, on their anatomical features and it is altered by ageing-associated weakening. However, a clear characterisation of these features, highly relevant for older individuals, is still lacking. This study hence aimed at characterising muscle volume, length, and physiological cross-sectional area (PCSA) and their variability, between body sides and between individuals, in a group of post-menopausal women. Lower-limb magnetic resonance images were acquired from eleven participants (69 (7) y. o., 66.9 (7.7) kg, 159 (3) cm). Twenty-three muscles were manually segmented from the images and muscle volume, length and PCSA were calculated from this dataset. Personalised maximal isometric force was then calculated using the latter information. The percentage difference between the muscles of the two lower limbs was up to 89% and 22% for volume and length, respectively, and up to 84% for PCSA, with no recognisable pattern associated with limb dominance. Between-subject coefficients of variation reached 36% and 13% for muscle volume and length, respectively. Generally, muscle parameters were similar to previous literature, but volumes were smaller than those from in-vivo young adults and slightly higher than ex-vivo ones. Maximal isometric force was found to be on average smaller than those obtained from estimates based on linear scaling of ex-vivo-based literature values. In conclusion, this study quantified for the first time anatomical asymmetry of lower-limb muscles in older women, suggesting that symmetry should not be assumed in this population. Furthermore, we showed that a scaling approach, widely used in musculoskeletal modelling, leads to an overestimation of the maximal isometric force for most muscles. This heavily questions the validity of this approach for older populations. As a solution, the unique dataset of muscle segmentation made available with this paper could support the development of alternative population-based scaling approaches, together with that of automatic tools for muscle segmentation.

Relationship of quadriceps muscle power and optimal shortening velocity with angiotensin-converting enzyme activity in older women.

BackgroundThe goal of this study was to assess whether angiotensin-converting enzyme (ACE) activity is related to muscle function (strength, power and velocity), as well as to assess if ACE inhibitors (ACEIs) and other angiotensin system blocking medications (ASBMs) influence muscle performance in elderly women.Subjects and methodsNinety-five community-dwelling elderly women took part in this study. Anthropometric data, blood ACE activity analysis, maximum power (Pmax) and optimal shortening velocity (υopt) of the knee extensor muscles, handgrip strength, physical activity (PA) and functional performance were measured.ResultsWomen taking ACEI were on average almost 2 years older than the women who did not take ACEI. They took more medicines and were also characterized by significantly lower level of ACE, but they did not differ in terms of PA level, results of functional performance and parameters characterizing muscle functions. No correlations of ACE activity with Pmax and handgrip strength, as well as with PA or functional performance were found. Higher ACE activity was connected with lower υopt for women who did not take any ASBMs (rho =−0.37; p=0.01).ConclusionSerum ACE activity was not associated with muscle strength, power and functional performance in both ASBM users and nonusers, but was associated with optimal shortening velocity of quadriceps muscles in older women. Further prospective studies are needed to assess if ACEIs or other ASBMs may slow down the decline in muscle function and performance.

Magnetic Resonance Imaging and Spectroscopy to Assess Leg Muscle Macrostructure and Microstructure in Healthy Older Women: A Feasibility Assessment

BackgroundAdvanced magnetic resonance (MR) scanning techniques, such as diffusion tensor imaging (DTI) and proton MR spectroscopy (1H-MRS) permit microstructural evaluation of water diffusivity and intramyocellular lipid content, respectively. We aimed to determine the feasibility of performing advanced MR scanning (proton density [PD] weighted imaging, DTI, and 1H-MRS) to evaluate properties of leg muscles in older women with respect to: (1) participant recruitment using three community-based strategies; (2) participant tolerance to the MRI scan acquisition protocol; and (3) scan acquisition and analyses protocols. MethodsRecruitment feasibility was evaluated based on the number of participants enrolled using various strategies. Participant tolerance was feasible if the scanning session was uninterrupted and image artifacts were absent. Optimal PD imaging, DTI, and 1H-MRS acquisition and analyses protocols were established. ResultsNine women (mean age = 71 years) were recruited over four months. The acquisition protocol was well tolerated by all participants. Adaptations were required for women with short stature and vertebral fracture risk. PD-weighted image analyses were improved by using the phased array uniformity enhancement filter to increase tissue contrast. ConclusionsIt is feasible to use a combination of MR scanning methods to evaluate muscle macrostructure and microstructure in the leg of older women. Our findings suggest that advanced MR scanning methods can be used for future studies interested in quantifying components of muscle structure in older women, but prospective studies are needed to confirm whether change in microstructure can be detected in response to an intervention.

Effect of Ibuprofen and Exercise Training on Bone, Body Composition and Strength in Older Women

Chronic low-grade systemic inflammation occurs in part due to increased pro-inflammatory cytokines mediated via cyclooxygenase (COX) pathways and contributes to excessive loss of muscle and bone mass with age. Administration of ibuprofen, a non-steroidal anti-inflammatory drug (NSAID) with inhibitory effects on COX, after resistance training enhances muscle mass in older individuals (Trappe et al. 2011) and hip areal bone mineral density (aBMD) in young women (Kohrt et al. 2010). PURPOSE: To examine the effects of longer term (i.e. 9 months) exercise training with ibuprofen supplementation (given after exercise sessions) on bone and muscle in older women. METHODS: Participants (n = 60, 64.8 ± 4.4y) were randomly assigned (double blind) to supervised resistance training or stretching 3d/week, and ibuprofen (400mg, post-exercise) or placebo (i.e. 4 groups) for 9 months. Baseline and post-intervention testing included: a) dual energy x-ray absorptiometry (DXA) for total body, lumbar spine, and hip aBMD, and total body lean tissue and fat mass; b) predicted 1-repetition maximum (1-RM) testing (biceps curl, hack squat). Data was analyzed with SPSS using alpha value of 0.05 via 3-factor ANOVA with two between-groups factors (ibuprofen versus placebo, resistance versus stretching), and one repeated-measures factor (baseline versus 9 month post-testing) controlling for age as a covariate. RESULTS: There was no effect of the ibuprofen on any of the dependent variables. There was a significant exercise x time interaction for biceps curl strength (p<0.01; resistance training increased 23% versus 3% for stretching), hack squat strength (p<0.01; resistance training increased110% versus 15% for stretching), and total body fat mass (p=0.04; resistance training decreased 2% versus 2% increase with stretching). There were trends for exercise x time interactions for aBMD at the total body (p = 0.07; 0.3% increase for the resistance training versus stretching decrease of 0.5%), and lumbar spine (p = 0.11; 0.6% decrease in the resistance training group versus 0.8% decrease for stretching). CONCLUSIONS: Resistance exercise increased strength, decreased fat mass, and trended towards improving aBMD of the total body and lumbar spine. Ibuprofen supplementation following exercise showed no additional benefits. Supported by the Canadian Institutes of Health Research

Time course of low- and high-volume strength training on neuromuscular adaptations and muscle quality in older women

This study investigated the effects of low- and high-volume strength trainings on neuromuscular adaptations of lower- and upper-body muscles in older women after 6weeks (6WE), 13weeks (13WE), and 20weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise, while the HV group performed three sets, 2days/week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower- and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low- and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20weeks of training.

Size of the abductor hallucis muscle in older women with hallux valgus

Toe deformities are highly prevalent in older people with up to 74% of older men and women having some degree of hallux valgus [1]. Despite the well documented hypotheses that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities [2], there has been little evidence to support this theory. Only one study has directly compared the toe flexor strength of individuals with toe deformities to those without, revealing that older people with hallux valgus have reduced hallux strength compared to those without the deformity [3]. Therefore, to further investigate the pathomechanics of hallux valgus, this study aimed to determine whether the size of the abductor hallucis muscle differed in older women with and without hallux valgus deformity.

Arterial Elasticity, Strength, Fatigue, and Endurance in Older Women

Arterial health may influence muscle function in older adults. Study purpose was to determine whether arterial elasticity is related to strength, central and peripheral fatigue, fatigue at rest, and treadmill endurance. Subjects were 91 healthy women aged >60. Treadmill endurance and maximal oxygen uptake (VO2 max) were measured. Peripheral and central fatigue for the knee extensors were evaluated using two isometric fatigue tests (one voluntary and one adding electrical stimulation). Arterial elasticity was determined using radial artery pulse wave analysis. Linear multiple regression was used in statistical analysis. Large artery elasticity was associated with central fatigue (P < 0.01) and treadmill endurance (P < 0.02) after adjusting for VO2 max and knee extension strength. Subjective fatigue at rest was related to large artery elasticity after adjusting for ethnic origin (<0.02). Strength was significantly related to small artery elasticity after adjusting for ethnic origin, leg lean tissue, age, and blood pressure. Arterial elasticity is independently related to strength and fatigue in older women, especially in the central nervous system where arterial elasticity is independently related to perceptions of fatigue at rest and central fatigue. These results suggest that arterial health may be involved with the ability of the central nervous system to activate muscle in older women.

Differences in Muscle Protein Synthesis and Anabolic Signaling in the Postabsorptive State and in Response to Food in 65–80 Year Old Men and Women

Women have less muscle than men but lose it more slowly during aging. To discover potential underlying mechanism(s) for this we evaluated the muscle protein synthesis process in postabsorptive conditions and during feeding in twenty-nine 65–80 year old men (n = 13) and women (n = 16). We discovered that the basal concentration of phosphorylated eEF2Thr56 was ∼40% less (P<0.05) and the basal rate of MPS was ∼30% greater (P = 0.02) in women than in men; the basal concentrations of muscle phosphorylated AktThr308, p70s6kThr389, eIF4ESer209, and eIF4E-BP1Thr37/46 were not different between the sexes. Feeding increased (P<0.05) AktThr308 and p70s6kThr389 phosphorylation to the same extent in men and women but increased (P<0.05) the phosphorylation of eIF4ESer209 and eIF4E-BP1Thr37/46 in men only. Accordingly, feeding increased MPS in men (P<0.01) but not in women. The postabsorptive muscle mRNA concentrations for myoD and myostatin were not different between sexes; feeding doubled myoD mRNA (P<0.05) and halved that of myostatin (P<0.05) in both sexes. Thus, there is sexual dimorphism in MPS and its control in older adults; a greater basal rate of MPS, operating over most of the day may partially explain the slower loss of muscle in older women.

Velocity of shortening accurately predicts myosin isoform in permeabilized single fibers from the vastus lateralis muscle in older women

The purpose of this study was to determine whether myosin heavy chain (MHC) isoforms could be predicted accurately based on velocity of shortening of permeabilized single muscle fibers obtained from biopsies of vastus lateralis (VLT) muscle. Complete force-velocity relationships were determined for 200 single fibers. A rectangular hyperbola was fitted to each set of force-velocity measurements. The velocity at which the hyperbola passed through a force equivalent to 2.5% of maximum isometric tension (V2.5) served as the index of fiber shortening speed. Fibers were classified as fast if the V2.5 was greater than 0.6 fiber-lengths·s−1 (Lf · s−1) and slow if V2.5 was less than 0.6 Lf · s−1. Fibers were stored at −80°C until analyzed for MHC isoform based on silver stained polyacrylamide gels (PAGE). Based on the PAGE assays, conflicting, or no results, were obtained on 16% of the fibers assayed and these were eliminated from further analysis. Of the 168 fibers remaining, 18 (11%) showed evidence of more than one MHC and were classified as hybrid fibers. Two of the 168 fibers (1.2%) gave results that were contradictory to the MHC isoform predicted by the V2.5. In contrast to the PAGE analysis, that did not yield data for 16% of the fibers analyzed, the classification based on V2.5 was 99.8% accurate for the determination of MHC isoform of permeabilized single fibers. We conclude that for fibers from VLT muscles of humans, V2.5 predicts fiber type reliably, eliminating the need for running labor intensive PAGE gels. Supported by the Michigan Life Sciences Corridor.

Effects of eccentric training on torque–angular velocity–power characteristics of elbow flexor muscles in older women

The purpose of this study was to investigate the potential of eccentric training to improve elbow flexor muscle power in elderly subjects. Fourteen older female volunteers (age range 60–78 years) were randomly assigned into either a training group (TG) or a control group (CG). For the TG, the 21-session 7-week eccentric training program consisted of 5×6 eccentric muscle actions at 60–100% of concentric three maximal repetitions. Before and after training, maximal elbow flexions were performed against increasing inertia. Maximal isokinetic elbow flexions at four angular velocities (eccentric actions, −60° s −1, −30° rad s −1; concentric actions, 30, 60° s −1) and maximal isometric actions were also performed. Maximal power ( P max) and an index of maximal shortening velocity ( VI max) were determined. For all action conditions, the myoelectric activities of the biceps and the triceps brachii muscles were recorded and quantified as a root mean square (RMS) value. In the TG, maximal torque developed under isometric, isokinetic and inertial conditions increased significantly after training (ranging from 11 to 19%). P max and VI max also increased significantly (31.3 and 25.9%, respectively). These parameters remained unchanged in the CG. The RMS activity of the biceps and triceps muscles was not affected by eccentric training for all action conditions excepting the eccentric condition at −30° s −1 where the RMS activity of the biceps increased significantly. The gains in maximal torque, P max and VI max observed after training would result more from intramuscular modifications than from changes in muscular activity, except for eccentric condition at −30° s −1 where the torque gains could also be partly explained by a reduction in inhibition of the motor unit pool.