Ronaldo Gabriel

Influence of obesity and sarcopenic obesity on plantar pressure of postmenopausal women

BACKGROUND Menopause is associated with a decrease in fat-free mass and an increase in fat mass. Sarcopenic obesity is more strongly associated with physical limitations than either obesity or sarcopenia and their effect in plantar pressure is not known. Consequently, the scope of the present study was to examine the effect of obesity and sarcopenic obesity on plantar pressure of postmenopausal women, during walking. METHODS Body composition and biomechanics parameters of plantar pressure were assessed in 239 postmenopausal women. FINDINGS Compared to non-obese and non-sarcopenic women, obese postmenopausal women have higher peak pressure in the metatarsal areas 1, 4, 5, midfoot and lateral heel and higher absolute impulses in all metatarsal and heel areas. On the other hand, sarcopenic obese postmenopausal women presented higher peak pressure and absolute impulses under all metatarsal areas, midfoot and heels. When the absolute values of maximal peak pressures and absolute impulses were normalised to body mass, pressure increases were only perceived for midfoot. INTERPRETATION The pressure increase found in different foot areas of obese and particularly in sarcopenic obese could cause discomfort and pain in the foot. Sarcopenic obese postmenopausal women also present a higher loading during the stance phase comparing with non-sarcopenic non-obese, fact that might limit their basic daily activity tasks, such as walking.

Triceps-surae musculotendinous stiffness: relative differences between obese and non-obese postmenopausal women.

BACKGROUND There is a lack of research into the relationship between obesity and muscle-tendon unit stiffness in postmenopausal women. Muscle-tendon unit stiffness appears to affect human motion performance and excessive and insufficient stiffness can increase the risk of bone and soft tissue injuries, respectively. The aim of this study was to investigate the relationship between muscle-tendon unit stiffness and obesity in postmenopausal women. METHODS 105 postmenopausal women (58 [SD 5.5] years) participated. Four groups (normal weight, pre-obese, obesity class I and obesity class II) were defined according World Health Organization classification of body mass index. The ankle muscle-tendon unit stiffness was assessed in vivo with a free oscillation technique using a load of 30% of maximal voluntary isometric contraction. FINDINGS ANOVA shows significant difference in muscle-tendon unit stiffness among the groups defined (P<0.001). Post hoc analysis reveals significant differences between the following groups: normal weight-pre-obese; normal weight-obesity class I and normal weight-obesity class II. The normal weight group had stiffness of 15789 (SD 2969) N/m, pre-obese of 19971 (SD 3678) N/m, obesity class I of 21435 (SD 4295) N/m, and obesity class II of 23497 (SD 1776) N/m. INTERPRETATION Obese subjects may have increased muscle-tendon unit stiffness because of fat infiltration in leg skeletal muscles, range of motion restrictions and stability/posture reasons and might be more predisposed to develop musculoskeletal injuries. Normal weight group had identical stiffness values to those reported in studies where subjects were not yet menopausal, suggesting that stiffness might not be influenced by menopause.

The relationship of body mass index, age and triceps-surae musculotendinous stiffness with the foot arch structure of postmenopausal women.

BACKGROUND Low- or high-arched feet and insufficient or excessive muscle-tendon stiffness have been identified as risk factors for lower extremity injuries. Additionally, increased body mass index and age may be responsible for structural changes of the foot, which might adversely affect the functional capacity of the longitudinal arch. Therefore, the aim of this study was to investigate the relationship of body mass, age and triceps-surae musculotendinous stiffness with the foot arch structure of postmenopausal women. METHODS 81 post menopausal women (58.0 (SD 6.0) years) participated. An in vivo free oscillation technique was used to assess musculotendinous stiffness of the ankle. The two-step protocol was used to acquire gait plantar pressure data. Dynamic arch index was calculated as the ratio of the midfoot area to the area of the entire foot excluding the toes. Three groups were formed (cavus, normal and planus). FINDINGS Significant differences (P<0.05) between the groups cavus and planus were found for age using the ANOVA test. Using Kruskal-Wallis tests significant differences were found for body mass index between the cavus-normal groups and cavus-planus (P<0.001) but no significant differences were found for triceps-surae musculotendinous stiffness between foot-type groups. INTERPRETATION Since obese subjects present greater downward vertical forces, they might be more prone to overload foot structures leading to the collapse of the medial longitudinal arch affecting adversely the functional capacity of the foot. Deterioration of the musculoskeletal system, due to age, may also affect foot arch structure. No relationship between musculotendinous stiffness and foot arch structure appears to exist.

Nível de atividade física para prevenção do excesso de gordura visceral em mulheres pós-menopáusicas: quanto é necessário?

OBJECTIVE: To analyze the level of physical activity (kcal/week) needed to prevent excess visceral fat in postmenopausal women. SUBJECTS AND METHODS: The sample included 239 women with a mean age of 57.2 years. Visceral fat area (VFA) was measured by octopolar bioelectrical impedance, and physical activity, by the long version IPAQ. ROC Curves (Receiver Operating Characteristic) were drawn, and a 95% confidence interval was used. RESULTS: The areas under the ROC curve for moderate physical activity and walk proved to be significant. Weekly expenditure of 1,601 kcal in walking, or 2,283 kcal in moderate physical activity were identified as good cutoff values to prevent excess VFA. CONCLUSION: Mild to moderate physical activity, with a caloric expenditure between 1,601 and 2,283 kcal/week, prevents excess central adiposity in postmenopausal women.

Effects of body composition and menopause characteristics on maximal oxygen uptake of postmenopausal women

Objective:The aim of this study was to identify the effects of body composition and menopause characteristics on maximal oxygen uptake (V˙O2max) variation in postmenopausal women. Methods:The study was conducted on 208 healthy women aged 49 to 79 years. Data related to menopause were obtained through medical history. Measurements of fat mass, visceral fat area, skeletal muscle mass (SM), fat-free mass, and basal metabolic rate were assessed by octopolar bioimpedance. SM index was calculated using the formula SM index = SM/weight, and V˙O2max was assessed through a modified Bruce protocol. Results:Cardiorespiratory fitness was negatively associated with age, percent fat mass, visceral fat area, body fat-muscular condition, and central adiposity-muscular condition. Only time elapsed since menopause revealed a statistically significant correlation with V˙O2max. Age and time of menopause aside, body fat-muscular condition was related to the V˙O2max variation, presenting an interactive effect with basal metabolic rate. Central adiposity-muscular condition also affects V˙O2max; however, the association of all interactions, age, basal metabolic rate, and time elapsed since menopause was not significant. Conclusions:Our data suggest an impairment of cardiorespiratory fitness with increasing age and time elapsed since menopause, but especially in the presence of increased total and central adiposity or reduced SM index. Body fat-muscular condition was significantly related to the V˙O2max variation, regardless of age and time elapsed since menopause, but not of basal metabolic rate. Central adiposity-muscular condition was a significant and independent factor of the V˙O2max exercise-related variations.

Biomechanical properties of the triceps surae muscle–tendon unit in young and postmenopausal women

BACKGROUND Insufficient and excessive stiffness may increase the risk of soft tissue and bone injuries, respectively, while the resonance frequency seems to be related with energy expenditure and stiffness. With aging and menopause muscle weakness, physical fragility and mobility limitations are also expected. Therefore this study addresses the differences of biomechanical properties of the triceps surae muscle-tendon unit between young and postmenopausal women. METHODS 39 young and 37 postmenopausal women participated. The biomechanical properties of the triceps surae muscle-tendon unit were assessed in vivo using a free oscillation technique involving 30% of the maximal voluntary isometric contraction load. FINDINGS The postmenopausal women in this study show significant higher values in the damped natural frequency of oscillation (young 3.84Hz vs. postmenopausal 4.68Hz, P<0.001), muscle-tendon unit stiffness (young 16,446N/m vs. postmenopausal 23,229N/m, P<0.001), and muscle-tendon unit stiffness normalized by mass (young 286.3N/m vs. postmenopausal 325.1N/m, P<0.05). The postmenopausal study group shows significant lower values in the damping ratio (young 0.190 vs. postmenopausal 0.150, P<0.01) than young women. INTERPRETATION The postmenopausal subjects may not be able to take advantage of resonance as the young subjects, or, the relationship between these frequencies is adjusted according to the musculoskeletal characteristics of each group. The decrease in damping properties and the increase in muscle-tendon unit stiffness suggest that postmenopausal women might be at a greater risk of injury.

Effects of a 12-month multi-component exercise program on the body composition of postmenopausal women

Abstract Objective The aims of this study were to identify the effects of a 12-month exercise program on the body composition of postmenopausal women and to examine the interaction of menopause characteristics (nature and time since menopause, hormone therapy) with exercise. Methods A total of 158 postmenopausal Caucasian women were analyzed in this study (70 in the control and 88 in the exercise group). This subset is part of the ‘Shape up during menopause’ which is a program that aims to develop exercise and health promotion in postmenopausal women. Exercise and control groups were tested before and at the end of the program. Data related to menopause were obtained through medical history. Measurements of fat mass, visceral fat area, skeletal muscle mass, fat-free mass, soft lean mass, and basal metabolic rate were assessed by octopolar bioimpedance. Results Alongside basal metabolic rate, all the anthropometric and body composition variables were influenced by the exercise program. The major differences between groups were found in skeletal muscle mass, total soft lean mass, fat-free mass, and skeletal muscle mass index (effect sizes ranged from 0.89 to 6.64). There were no interactive effects found between exercise and menopause characteristics. Conclusions There were positive changes in all measured variables and no significant interactive effects with menopause characteristics; therefore, our data suggest that exercise alone promoted improvements in the body composition of postmenopausal women.

Ação do laser terapêutico e do ultrassom na regeneração nervosa periférica

Objective: To assess the efficacy of early therapeutic laser and ultrasound in the regeneration process of an injury in rats. Methods: We used 24 rats. Eighteen underwent surgery for sciatic nerve compression by a hemostat above the popliteal fossa. The animals were divided into three groups of six animals each. Normal control group. GI: Injured control without therapeutic intervention. GII: laser ArGaAl therapeutic intervention. GIII: therapeutic intervention of Pulsed Ultrasound. We begin therapeutic interventions 24 hours after injury, with daily applications for a period of fourteen consecutive days. Results: In assessing the girth of the muscles of the right they, the following average decrease (in mm) for each GI: 0.45, GII: 0.42, GIII: 0.40 In relation to travel time, both GII and GIII presented significant difference when compared to GI. In the final evaluation of the IFC, GII excelled in the GIII. As for the healing observed, a major great improvement was observed in GII and GIII. Conclusion: The results showed that nerve recovery was higher with the laser application. Level of evidence II, Therapeutic Studies – Investigation of the results of treatment.Objective To assess the efficacy of early therapeutic laser and ultrasound in the regeneration process of an injury in rats. Methods We used 24 rats. Eighteen underwent surgery for sciatic nerve compression by a hemostat above the popliteal fossa. The animals were divided into three groups of six animals each. Normal control group. GI: Injured control without therapeutic intervention. GII: laser ArGaAl therapeutic intervention. GIII: therapeutic intervention of Pulsed Ultrasound. We begin therapeutic interventions 24 hours after injury, with daily applications for a period of fourteen consecutive days. Results In assessing the girth of the muscles of the right they, the following average decrease (in mm) for each GI: 0.45, GII: 0.42, GIII: 0.40 In relation to travel time, both GII and GIII presented significant difference when compared to GI. In the final evaluation of the IFC, GII excelled in the GIII. As for the healing observed, a major great improvement was observed in GII and GIII. Conclusion The results showed that nerve recovery was higher with the laser application. Level of evidence II, Therapeutic Studies - Investigation of the results of treatment.

Exercise effects in plantar pressure of postmenopausal women.

Objective: The aim of this study was to investigate the effect of a 12-month moderate-to-vigorous exercise program on plantar pressure among postmenopausal women. Methods: A total of 121 white postmenopausal women participated in a randomized controlled trial (60 women in the exercise group and 61 women in the control group). Women in the exercise group attended training sessions of 60 minutes, 3 days per week, on nonconsecutive days. Weight and basal metabolic rate were evaluated by bioimpedance, and height was evaluated with a stadiometer. Plantar pressure data were collected using the Footscan platform and Software 7.1. Results: After the 1-year intervention, women from the exercise group had (1) lower body mass index, (2) equal basal metabolic rate, (3) lower peak pressures, and (4) lower absolute impulses compared with the women from the control group. Interaction between the exercise group and practice time was found for most of the maximal peak pressure areas (except for metatarsal 4), for all absolute impulse values, and for relative impulses in the hallux, metatarsal 4, midfoot, and medial heel. Conclusions: This study seems to prove that women who exercise have decreased loading of maximal peak pressures and absolute impulses and, consequently, self-reported pain, soreness, and discomfort in the lower extremity. An interaction effect between group and practice time was found for most of the variables considered, meaning that this 12-month exercise program is effective in the improvement of the biomechanic parameters of plantar pressure.

The upper limit of the cardiorespiratory training zone (40-84%HRR) is overestimated for postmenopausal women

OBJECTIVE The purpose of this study was to examine the heart rate reserve (HRR) at first and second ventilatory thresholds (VTs) in postmenopausal women and compare it with optimal intensity range recommended by the ACSM (40-84%HRR). An additional aim was to evaluate whether a higher aerobic power level corresponded to a higher HRR at VTs. METHODS Fifty-eight postmenopausal women participated in this study (aged 48-69). A graded 25 Wmin(-2) cycle ergometer (Monark E839) exercise protocol was performed in order to assess aerobic power. The heart rate and gas-exchange variables were measured continuously using a portable gas analyzer system (Cosmed K4b). The first (VT1) and the second (VT2) VTs were determined by the time course curves of ventilation and O2 and CO2 ventilatory equivalents. A K-means clustering analysis was used in order to identify VO2max groups (cut-off of 30.5 mlkg(-1)min(-1)) and differences were evaluated by an independent sample t-test. Bland-Altman plots were performed to illustrate the agreement between methods. RESULTS The womens HRR values at VT1 were similar to 40% HRR in both VO2max groups. At VT2 both VO2max groups exhibited negative differences (P<0.01) for the predicted 84%HRR intensity (-14.46% in the lower VO2max group and -16.32% in the higher VO2max group). CONCLUSIONS An upper limit of 84% overestimates the %HRR value for the second ventilatory threshold, suggesting that the cardiorespiratory target zone for this population should be lower and narrower (40-70%HRR).