Strength In Postmenopausal Women Research Articles

Association between moderate physical activity, spinal motion and back muscle strength in postmenopausal women with and without osteoporosis

Objective. The purpose of this study was to determine whether physical activity levels of postmenopausal women were associated with their bone mineral density (BMD), back extensor strength (BES), severity of thoracic kyphosis and range of spinal motion.Method. This study adopted a cross-sectional design. 189 female subjects from 50 to 80 years of age were divided into moderately active (n = 63) and sedentary (n = 126) groups according to their physical activity level, which is measured by the physical activity score. BMD (lumbar spine and hip), BES, severity of thoracic kyphosis and range of spinal motion in the sagittal and frontal plane were measured in each subject.Results. The groups differed significantly in the range of spinal motion in the sagittal plane (p = 0.01) (moderately active: 26.9±10.8; sedentary: 23.0±10.2), as well as in the right frontal plane (p < 0.001) (moderately active: 27.1 ± 6.4; sedentary: 23.4 ± 7.5) and left frontal plane (p < 0.001) (moderately active: 27.6 ± 6.5; sedentary 23.7 ± 7.4). There were no significant differences in BMD (active: 0.88 ± 0.18 g/cm2; sedentary: 0.98 ± 0.15 g/cm2), severity of thoracic kyphosis (active: 52.9 ± 12.4; sedentary: 51.9 ± 11.8) or BES (active: 49.0 N ± 14.6; sedentary: 46.6 N ± 15.1).Conclusions. This study demonstrates that active women had better range of spinal motion than sedentary women, but they did not differ significantly in severity of thoracic kyphosis, BES and BMD.

Soy isoflavones in the management of postmenopausal osteoporosis

This is a review article designed to address the effects of soy isoflavones on bone metabolism in postmenopausal women and their place in the prevention and treatment of postmenopausal osteoporosis. Soy isoflavones are natural products that could be used as an alternative to menopausal hormone therapy because they are structurally and functionally related to 17beta-estradiol. In vitro and animal studies have shown that they act in multiple ways to exert their bone-supporting effects. They act on both osteoblasts and osteoclasts through genomic and nongenomic pathways. Epidemiological studies and clinical trials suggest that soy isoflavones have beneficial effects on bone mineral density, bone turnover markers, and bone mechanical strength in postmenopausal women. However, there are conflicting results related to differences in study design, estrogen status of the body, metabolism of isoflavones among individuals, and other dietary factors. The long-term safety of soy isoflavone supplements remains to be demonstrated.

Interaction between playing golf and HRT on vertebral bone properties in post-menopausal women measured by QCT

We investigated the effect of playing regular golf and HRT on lumbar and thoracic vertebral bone parameters (measured by QCT) in 72 post-menopausal women. The main finding of this study was that there was positive interaction between golf and HRT on vertebral body CSA and BMC at the thoracic 12 and lumbar 2 vertebra but not the third and seventh thoracic vertebras. Identifying specific exercises that load the spine sufficiently to be osteogenic is an important component of primary osteoporosis prevention. The aim of this study was to determine if in postmenopausal women regular participation in golf resulted in greater paravertebral muscle mass and improved vertebral bone strength. Forty-seven postmenopausal women who played golf regularly were compared to 25 controls. Bone parameters at the mid-vertebral body were determined by QCT at spinal levels T3, T7, T12 and L2 (cross-sectional area (CSA), total volumetric BMD (vBMD), trabecular vBMD of the central 50% of total CSA, BMC and cortical rim thickness). At T7 and L2, CSA of trunk muscles was determined. There was a positive interaction between golf and HRT for vertebral CSA and BMC at T12 and L2, but not at T3 or T7 (p ranging < 0.02 to 0.07). Current HRT use was associated with a 10-15% greater total and trabecular vBMD at all measured vertebral levels. Paravertebral muscle CSA did not differ between groups. Vertebral CSA was the bone parameter significantly related to muscle CSA. These findings provide preliminary evidence that playing golf may improve lower spine bone strength in postmenopausal women who are using HRT.

Effects of Exercise Training with Weighted Vests on Bone Turnover and Isokinetic Strength in Postmenopausal Women

The effects of 12 wk of exercise training using weighted vests on bone turnover and isokinetic strength were evaluated in postmenopausal women randomly assigned as exercisers (EX; n = 9) or controls (CON; n = 7). Training included 3 multimodal exercise sessions per wk wearing weighted vests. The vest load was progressively increased each wk to a maximum of 15% of body weight. Bone turnover was determined from resting levels of serum osteocalcin and NTx. Knee and ankle strength were measured at 60 degrees/s and 180 degrees/s using an isokinetic dynamometer. After 12 wk, NTx decreased by 14.5% (P <or= .05) in EX, with no significant changes in osteocalcin. EX also showed a 40% (P <or= .05) improvement in ankle plantar-flexion strength at 60 degrees/s. Relative body fat significantly decreased and fat-free mass increased in EX. Exercise compliance was 80%. These findings support the use of progressive exercise training using weighted vests in postmenopausal women.

The influence of lifetime physical activity and calcium intake on current measures of bone strength in postmenopausal women

The influence of lifetime physical activity and calcium intake on current measures of bone strength in postmenopausal women

Vitamin K 2 improves bone strength in postmenopausal women

High vitamin K intake is associated with improved bone health and prevention of osteoporotic fractures. At nutritional doses, both vitamins K1 and K2 may contribute to optimizing bone mineral density; intervention studies suggest a synergistic effect with vitamin D and calcium. At higher intakes, vitamin K was demonstrated to also increase bone strength by improved bone geometry, but this effect was restricted to K2. In this paper we demonstrate that the side chain in K2 vitamins may be regarded as a geranylgeranyl derivative which inhibits osteoclast activation, probably via the inhibition of the mevalonate pathway. Although menaquinone-4 (MK-4) seems to be the obvious form of K2 to be used at pharmacological doses, arguments are provided that menaquinone -7 (MK-7) may be more effective at doses that do not exceed the present recommendations for daily vitamin K intake.

Power output, isometric strength and steadiness in the leg muscles of pre- and postmenopausal women; the effects of hormone replacement therapy

There are conflicting reports of the effects of hormone replacement therapy (HRT) on strength preservation in postmenopausal women, while any effect on power output has received little attention. Decreased steadiness of force generation has been reported in older muscles and may be related to the hormonal changes associated with the menopause, but the effect of HRT has not been investigated. We have studied the effect of HRT on strength, power output and isometric force steadiness in healthy women. Sixteen young (aged 27.4 +/- 1.4 years, mean +/- SEM) and 29 postmenopausal women were studied. Fifteen of the latter were taking HRT (68.1 +/- 1.4 years, HRT+) and 14 (70.5 +/- 1.5 years, HRT-) had never done so. During isometric quadriceps contractions the force steadiness (coefficient of variation of force) was measured at 10, 25, 50 and 100% maximum voluntary contraction (MVC). The average power generated by an explosive leg extension was recorded. The HRT- group generated less power (110.2 +/- 7.2 W) than both the HRT+ (136.5 +/- 10.9 W, P = 0.027) and young (136.2 +/- 5.8 W, P = 0.027) subjects. Power output was similar in the HRT+ and younger subjects. The HRT- subjects were weaker than the younger ones (241.3 +/- 14.0 N vs. 297.6 +/- 13 N, P = 0.006). The strength of the HRT+ group (255.5 +/- 14 N) was not significantly different to the other two groups. There was no difference in steadiness between the three groups at any of the force levels. HRT appears to maintain power output to a greater extent than isometric strength in postmenopausal women. There was no evidence for an effect of either age or HRT on isometric steadiness in the quadriceps.

Six months of hormone replacement therapy does not influence muscle strength in postmenopausal women

Objectives: Postmenopausal hormone replacement therapy (HRT) has positive effects on fracture incidence before any effects on bone mineral density can be demonstrated. This has been attributed to increased muscle strength by HRT. This study was designed to evaluate the effect of 6 months of HRT on muscle strength in postmenopausal women. Methods: Forty postmenopausal women, aged 60–78 were included in the study. They were randomly divided in two groups with 20 women in each group. One group received Menorest® 50 μg/24 h (estradiol 4.3 mg) and Gestapuran 2.5 mg (medroxyprogesteron) daily and the other group received placebo treatment. The study was conducted as a double blinded, prospective and placebo controlled trial. Hand grip strength, isokinetic knee flexion and extention, and physical activity were measured before treatment, after 3 and 6 months. Physical activity was estimated using a classification system of physical activity. A JAMAR hydraulic hand dynamometer and a Cybex II dynamometer were used to evaluate muscle strength. Results: Hand grip strength in the right hand, increased significantly in both groups (HRT P<0.001 and placebo P<0.01) and in the left hand in the HRT group ( P<0.01). However, there were no differences in muscle strength between the two groups. There was no significant change in isokinetic knee flexion or extension after 6 months in either of the groups. The estimated physical activity increased slightly in the placebo group, but there was no significant difference compared to the treatment group. Conclusions: Our data suggest that 6 months of HRT does not influence muscle strength in postmenopausal women.

Muscle strength and tibolone: a randomised, double‐blind, placebo‐controlled trial

To investigate the effects of tibolone, a tissue-specific compound with a mixed (estrogenic, progestogenic and androgenic) hormonal profile, on skeletal muscle strength in a group of healthy postmenopausal women. Randomised, parallel group, double-blind, placebo-controlled, single-centre trial conducted between August 1997 and July 1999. Eighty-five healthy women, between one and 15 years postmenopausal, (mean [SD] age, 54.2 [4.7] years) recruited from local paper advertisements. Participants were randomly assigned to 2.5 mg tibolone or to identically appearing placebo pills daily for 12 months, taken orally in the morning. Both maximal handgrip strength, representing upper body strength, and maximal quadriceps strength, representing lower body strength, were measured isometrically. Treatment effect estimates (between group differences) in handgrip strength and isometric knee extension at last visit. Tibolone significantly (P = 0.04) increased handgrip strength compared with placebo (difference 0.99 kg, [95% CI 0.1-1.9]). No significant treatment effect (P = 0.61) was observed in isometric knee extension strength. Isometric strength adjusted for body mass index resulted in a trend favouring tibolone (P = 0.06). Individual trend analysis showed a significant difference in rate of change throughout the year (6.8% [95% CI 2.1-10.7]) favouring tibolone. Administration of tibolone increased handgrip strength in postmenopausal women compared with placebo. A trend indicating a positive effect in isometric knee extension strength adjusted for body mass index was observed. Tibolone seems to mitigate the menopause-related decline in muscle strength.

Effects of physical activity and menopausal hormone replacement therapy on postural stability in postmenopausal women — a cross-sectional study

Objectives: Poor postural stability and muscular strength in postmenopausal women are associated with increased risk of falls and fractures. This study examined whether these risk factors for falls differed according to habitual physical activity and menopausal hormone replacement therapy (HRT) use. Methods: Subjects were 117 postmenopausal women (mean age 65.3±6.0 years); of whom 70 had taken HRT for at least 5 years (42 tibolone and 28 transdermal oestradiol), whilst 47 had not received HRT. Duration of physical activity was assessed with monitors worn on a waist belt. Subjects were grouped into low (LPA; ≤15 min day −1) or high (HPA; >15 min day −1) physical activity. Postural stability was assessed using a swaymeter which measured displacement at the waist. Maximal isometric strength of knee flexors was determined in 23 of the tibolone group, 26 of the oestrogen group and 12 of the no therapy group. Results: Stature and body mass did not differ according to physical activity participation or HRT use, although the more active women were on average 2.5 years younger than the less active women. Body sway was lower in more physically active women in three of the four measurement conditions ( P<0.05) and this effect persisted after inclusion of age as covariate. Body sway tended to be highest in the no therapy group, although not significantly so. Mean knee extensor strength was higher in women taking tibolone and oestrogen than in those not on therapy (115.3 (5.2), 118.2 (7.2) and 97.6 (9.3) Nm, respectively), although again this difference was not statistically significant. Conclusions: The more physically active postmenopausal women had significantly better postural stability than less active women, whilst HRT had no significant effect. Physical activity might thus have a role in reducing the risk of fracture through reducing the risk of falling.

Evaluation of the applicability of HRT as a preservative of muscle strength in women

Objectives: To review the studies that have been undertaken on the effects of postmenopausal hormone replacement therapy (HRT); especially oestrogen (+progestin) regimens on the preservation of muscle strength. Current knowledge of the mechanisms and actions of steroid- and sex hormones on skeletal muscle tissue will be used in an attempt to clarify the mechanism of action of a possible effect. The objective is to arrive at an agreement on whether or not postmenopausal oestrogen administration has a positive influence on skeletal muscle tissue. Methods: Peer-reviewed publications were assessed. Results: An age-related decrement in muscle strength can be found in both men and women. However, in women, an extra decline can be observed around the time of menopause. A possible relationship between the additional diminution in muscle strength and altered hormone concentrations after the onset of menopause has been suggested. Since women nowadays spend one-third of their life postmenopausal, it is extremely important to keep the decline in muscle mass as small as possible. Besides the continuation of a physically active lifestyle, HRT was suggested to serve as a protective mechanism. Although, the usefulness of HRT as a preservative of muscle strength appeared controversial. Conclusions: Skeletal muscle strength is sensitive to training up to a high age, though continuation of physical activity does not appear to protect skeletal muscles completely from age-related decrements. Therefore, the development of another preventive method would be useful. Considering the present knowledge it has all the hallmarks that HRT can be a useful tool in the maintenance of muscle strength in postmenopausal women. None the less, further research is necessary to endorse this theory.

Effect of bone loading exercises program on grip strength in postmenopausal women

Effect of bone loading exercises program on grip strength in postmenopausal women

Strength improvements with 1 yr of progressive rsistance training in older women

Thirty-nine healthy women (59.5 +/- 0.9 yr) were randomized to either a control group (CON) or a progressive resistance training group (PRT) that trained twice weekly for 12 months. PRT trained at 80% or more (average of 84%) of their most recent one repetition maximum (1RM) on the lateral pull-down (LPD), knee extensor (KE), and double leg press (DLP) apparatus. One RM was measured for each exercise once monthly in PRT and at baseline, midstudy, and end of study in CON. One RM significantly increased in PRT for all muscle groups trained compared to CON (P < 0.0001). Increases of 73.7 +/- 12%, 35.1 +/- 3%, and 77.0 +/- 5%, respectively, for KE, DLP, and LPD in PRT and 12.7% +/- 8%, 3.7% +/- 3%, and 18.4% +/- 4%, respectively, in CON were observed. Approximately 50% of the gains in KE and LPD and 40% in the DLP were seen in the first 3 months of the study. In all three exercises, strength gains in PRT continued over the entire 12-month period. These data indicate that high-intensity strength training results in substantial, continual increases in strength in postmenopausal women for at least 12 months, with the greatest gains seen in the first 3 months of training.

91309485 Research study. The effect of trunk resistive exercise on muscle strength in postmenopausal women

91309485 Research study. The effect of trunk resistive exercise on muscle strength in postmenopausal women

The Effect of Trunk Resistive Exercise on Muscle Strength in Postmenopausal Women

At the time this study was conducted. Ms. O'Dwyer and Ms. Lin were physical therapy master's degree students. Dr. Blanpied was a doctoral student. This paper was presented at the First International Orthopaedic Symposium in Ottawa, Canada, in May, 1990. This study was supported by Grant RR59 from the General Clinical Research Centers Program, Division of Research Resources, NIH, and by an Aging Seed Grant from The University of Iowa.Fifty-five women with an average age of 56 years participated in a study to determine the effects of a quantitatively based home exercise program on trunk muscle strength. The same body positions were used for testing trunk strength and for the exercise program. During the strength tests, the external forces generated by the subjects were measured using the trunk attachment of the Muscle Evaluation and Exercise Dosimeter (MEED) 3000 System. The standardized exercise program utilized the body segments and cuff weights on the extremities to achieve the desired resistance level for the sit-up, prone trunk extension, and double-leg flexion exercises. Three sets of 10 were performed for each exercise at least three times a week over a 12-month period. Large, significant (p < .05) strength gains (25-30%) were made by the exercise group for each exercise. The performance of the exercise group was superior to the control group. The reliability of the strength-using tests determined by interday trials using the MEED 3000 was high-all correlations were r = .93 or higher. This study demonstrates that older women can tolerate and increase trunk muscle strength using controlled, progressive, resistive exercise over a long period of time. The exercise approach in this study might be considered for use in treatment of low back dysfunction. J Orthop Sports Phys Ther 1991;13(6):300-309.

The decline of grip strength in the menopause: Relationship to physical activity, estrogen use and anthropometric factors

The focus of this study was the relationship of grip strength to age, physical activity and anthropometric factors, in a population of 255 post-menopausal women not on estrogen therapy (mean age = 57.6) and 55 women currently on estrogen replacement therapy (mean age = 56.9). Grip strength was measured as an indicator of muscular strength in the upper limbs. The grip strength of the estrogen users was significantly higher than that of the estrogen abstainers. Grip strength was related to age ( r = −0.25, p < 0.01), and the body habitus parameters of height ( r = 0.36, p < 0.01) and weight ( r = 0.18, p < 0.01). Although estrogen use was univariately correlated with strength ( r = 0.16, p < 0.05), multiple regression analyses revealed that only the height, age and physical activity were independent determinants of grip strength. These data suggest: (1) height is the major determinant of upper body strength in older women; (2) the reduction in physical activity with advancing age may contribute to strength decline, and modest increase in physical activity may retard the loss of strength that accompanies aging: (3) the loss of ovarian estrogen in menopause may be related to the loss of strength in postmenopausal women.