Muscular strength, bone density and body composition of a woman with systemic lupus erythematosus submitted to a resistance training program: A case report

Introduction. Physical activity can provide long-term benefits for systemic lupus erythematosus (SLE). Objective. This study sought to demonstrate the effects of progressive resistance training on the muscular strength, bone mineral density (BMD) and body composition of pre-menopausal women with SLE undergoing glucocorticoid (GC) treatment. Materials and Methods. This is the case report of a 43-year-old African-South American premenopausal woman with non-extensive SLE and low bone density. A six-month program with three bimonthly cycles of 70%, 80%, and 90% intensity according to the 10 maximum-repetition test was used. Dual-energy X-ray absorptiometry (DXA) was used to measure the BMD, T-scores and body composition, and indirect fluorescence was used to measure the levels of antinuclear antibodies. Student's t-test was used. Results. Statistical improvement was noted in all strength exercises, including the 45° leg press (Δ%=+50%, p<0.001) and knee extension (Δ%=+15%, p=0.003) to maintain the BMD of the L2-L4 lumbar (Δ%=+0.031%; p=0.46) as well as the trochanter (Δ%=+0.037%; p=0.31) and BMI (Δ%=-0.8, p=0.54). Conclusion. In this case study, the presented methodology had a positive effect on strength and contributed to the maintenance of BMD and body composition in a woman with SLE undergoing GC treatment. © 2012 Revista Andaluza de Medicina del Deporte.

Exercise-induced muscle damage and running economy in humans

Running economy (RE), defined as the energy demand for a given velocity of submaximal running, has been identified as a critical factor of overall distance running performance. Plyometric and resistance trainings, performed during a relatively short period of time (15-30 days), have been successfully used to improve RE in trained athletes. However, these exercise types, particularly when they are unaccustomed activities for the individuals, may cause delayed onset muscle soreness, swelling, and reduced muscle strength. Some studies have demonstrated that exercise-induced muscle damage has a negative impact on endurance running performance. Specifically, the muscular damage induced by an acute bout of downhill running has been shown to reduce RE during subsequent moderate and high-intensity exercise (>65% VOax). However, strength exercise (i.e., jumps, isoinertial and isokinetic eccentric exercises) seems to impair RE only for subsequent high-intensity exercise (90% VOax). Finally, a single session of resistance exercise or downhill running (i.e., repeated bout effect) attenuates changes in indirect markers of muscle damage and blunts changes in RE. © 2013 Cláudio de Oliveira Assumpção et al.

Lower limb strength is associated with gait biomechanical abnormalities in older female fallers and non-fallers

BACKGROUND: Age-related loss in lower limb strength is related with impaired mobility. However, the association between decreased lower limb strength and gait biomechanical abnormalities is unclear. %In line with this, With respect to these statements, our study aimed to compare the maximum isokinetic voluntary strength (MIVS) of hip, knee and ankle of older women with and without history of falls. Also, we correlate the strength of each group with gait biomechanics. METHODS: The MIVS were assessed during concentric/concentric movements performed for hip, knee and ankle joints. Gait biomechanics (kinematic and electromyography) were assessed during 1-minute recorded during the volunteers walking on the treadmill at self-selected speed. Electromyographic signal was analyzed by the linear envelop after heel strike and before toe-off. The kinematic data were analyzed using the variables: step time, length and step width and ankle angle at heel strike, and hip angle at toe-off. RESULTS: In faller group, we found that a decreased hip abduction and adduction MIVS is associated with a higher tibialis anterior activation at initial stance (p =0.04 and r =-0.53 and p=0.04 and r=-0.52). CONCLUSION: Therefore, an impaired strength of hip could causes compensation in ankle stabilizer muscles activation at initial stance in older female fallers. © 2013 - IOS Press and the authors. All rights reserved.

Air-particle abrasion on zirconia ceramic using different protocols: Effects on biaxial flexural strength after cyclic loading, phase transformation and surface topography

This study evaluated the effect of different air-particle abrasion protocols on the biaxial flexural strength and structural stability of zirconia ceramics. Zirconia ceramic specimens (ISO 6872) (Lava, 3M ESPE) were obtained (N=336). The specimens (N=118, n=20 per group) were randomly assigned to one of the air-abrasion protocols: Gr1: Control (as-sintered); Gr2: 50 μm Al2O3 (2.5 bar); Gr3: 50 μm Al2O3 (3.5 bar); Gr4: 110 μm Al2O3(2.5 bar); Gr5: 110 μm Al2O3 (3.5 bar); Gr6: 30 μm SiO2 (2.5 bar) (CoJet); Gr7: 30 μm SiO2(3.5 bar); Gr8: 110 μm SiO2 (2.5 bar) (Rocatec Plus); and Gr9: 110 μm SiO2 (3.5 bar) (duration: 20 s, distance: 10 mm). While half of the specimens were tested immediately, the other half was subjected to cyclic loading in water (100,000 cycles; 50 N, 4 Hz, 37 °°C) prior to biaxial flexural strength test (ISO 6872). Phase transformation (t→m), relative amount of transformed monoclinic zirconia (FM), transformed zone depth (TZD) and surface roughness were measured. Particle type (p=0.2746), pressure (p=0.5084) and cyclic loading (p=0.1610) did not influence the flexural strength. Except for the air-abraded group with 110 μm Al2O3 at 3.5 bar, all air-abrasion protocols increased the biaxial flexural strength (MPa) (Controlnon-aged: 1030±153, Controlaged: 1138±138; Experimentalnon-aged: 1307±184-1554±124; Experimentalaged: 1308±118-1451±135) in both non-aged and aged conditions, respectively. Surface roughness (Ra) was the highest with 110 μm Al2O3(0.84 μm. FM values ranged from 0% to 27.21%, higher value for the Rocatec Plus (110 μm SiO2) and 110 μm Al2O3 groups at 3.5 bar pressure. TZD ranged between 0 and 1.43 μm, with the highest values for Rocatec Plus and 110 μm Al2O3 groups at 3.5 bar pressure. © 2013 Elsevier Ltd.

Pelvic floor muscle strength evaluation in different body positions in nulliparous healthy women and its correlation with sexual activity

Objective: The aim of this study was to assess pelvic floor muscle (PFM) strength in different body positions in nulliparous healthy women and its correlation with sexual activity.Materials and Methods: Fifty healthy nulliparous women with mean age of 23 years were prospectively studied. Subjective evaluation of PFM was assessed by transvaginal digital palpation (TDP) of anterior and posterior areas regarding the vaginal introitus. A perineometer with inflatable vaginal probe was used to assess the PFM strength in four different positions: supine with extended lower limbs (P1); bent-knee supine (P2); sitting (P3); standing (P4).Results: Physical activity, 3 times per week, was reported by 58% of volunteers. Sexual activity was observed in 80% of women and 82% of them presented orgasm. The average body mass index (BMI) was 21.76 kg/m(2), considered as normal according World Health Organization (WHO). We observed that 68% of volunteers were conscious about the PFM contraction. TDP showed concordance of 76% when anterior and posterior areas were compared (p = 0.00014). There was not correlation between PFM strength and orgasm in subjective evaluation. The PFM strength was significantly higher in standing position when compared with the other positions (p < 0.000). No statistical difference was observed between orgasm and PFM strength when objective evaluations were performed.Conclusions: There was concordance between anterior and posterior areas in 76% of cases when subjective PFM strength was assessed. In objective evaluation, higher PFM strength was observed when volunteers were standing. No statistical correlation was observed between PFM strength and orgasm in nulliparous healthy women.

Influence of the resistance training on heart rate variability, functional capacity and muscle strength in the chronic obstructive pulmonary disease

Background. The chronic obstructive pulmonary disease (COPD) is associated with the strength and resistance decreasing in addition to the dysfunction on autonomic nervous system (ANS). The aerobic training isolated or in association with the resistance training showed evidence of beneficial effects on an autonomic modulation of COPD; however, there are no studies addressing the effect of isolated resistance training.Aims. This study aims at investigating the influence of resistance training on an autonomic modulation through heart rate variability (HRV), functional capacity and muscle strength in individuals with COPD.Design. Clinical series study.Setting. Outpatients.Population. The study involved 13 individuals with COPD.Methods. The experimental protocol was composed by an initial and final evaluation that consisted in autonomic evaluations (HRV), cardiopulmonary functional capacity evaluation (6-minute walk test) and strength evaluation (dynamometry) in addition by the resistance training performed by 24 sessions lasted 60 minutes each one and on a frequency of three times a week. The intensity was determined initially with 60% of one maximum repetition and was progressively increased in each five sessions until 80%.Results. The HRV temporal and spectral indexes analysis demonstrates improvement of autonomic modulation, with significant statistical increases to sympathetic and parasympathetic components of ANS representing by SDNN, LF and HF. In addition, it was observed significant statistical increases to shoulder abduction and. knee flexion strength and functional capacity.Conclusion. The exclusive resistance training performed was able to positively influence the autonomic modulation; in addition it promoted benefits on cardiorespiratory functional capacity and strength benefits in individuals with COPD.Clinical Rehabilitation Impact. This study could contribute to clinical and professionals researchers that act with COPD, even though the resistance component of pulmonary rehabilitation presents consensual benefits on several healthy indicators parameters. There is no evidence about the effects on HRV before. Moreover, this study showed, on clinical practice, the HRV uses as an ANS activity on sinus node evaluation and highlights further importance on scientific context.

Short-term changes in handgrip strength, body composition, and lymphedema induced by breast cancer surgery

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impact of gestational diabetes and lactational insulin replacement on structure and secretory function of offspring rat ventral prostate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Free-running circadian rhythms of muscle strength, reaction time, and body temperature in totally blind people

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hard machining, glaze firing and hydrofluoric acid etching: Do these procedures affect the flexural strength of a leucite glass-ceramic?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of Insertion Techniques for Resin Cement and Mechanical Cycling on the Bond Strength Between Fiber Posts and Root Dentin

Purpose: To evaluate the effect of the insertion technique for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin.Materials and Methods: Sixty-four single-rooted bovine teeth were endodontically prepared to receive glass-fiber posts. The insertion of cement into the root canal was performed using one of the following techniques: POS, insertion with the post; LEN, the use of a lentulo-type drill; EXP, insertion with a straight-tip explorer; or CEN, the use of a Centrix syringe. Half of the specimens were mechanically cycled. All specimens were sectioned into slices of 1.8 mm for the push-out test and 0.5 mm for analysis of the cement layer quality.Results: The insertion technique affected the interaction between factors (bond strength and mechanical cycling; p < 0.0001). Insertion of the Centrix syringe after mechanical cycling showed the highest bond values (13.6 +/- 3.2 MPa). Group-to-group comparisons for baseline and cycled conditions indicated that mechanical cycling significantly influenced the bond strength (p < 0.0001) of the POS and CEN groups. The quality of the cement layer did not differ between the techniques when evaluated in the middle (p = 0.0612) and cervical (p = 0.1119) regions, but did differ in the apical region (p = 0.0097), where the CEN group had better layer quality for the two conditions tested (baseline and cycled).Conclusion: The use of the Centrix syringe improved the homogeneity of the cement layer, reducing the defects in the layer and increasing adhesive strength values to dentin, even after mechanical cycling.

Effects of high and low volume of strength training on muscle strength, muscle volume and lipid profile in postmenopausal women

Changes in lipid profile are considered a risk factor for cardiovascular disease (CVD), especially in postmenopausal woman who have been associated with age-related loss of muscle mass. The beneficial role of aerobic exercise in the prevention of CVD has been well documented. However, the effect of strength training has not been established. The purpose of this study was to determine the changes of lipoprotein levels after 12 weeks of different volumes of strength training and its correlation with strength and muscle volume in postmenopausal women. The participants were randomized into three groups: low volume (LVST; n = 12, 1 set) and high volume of strength training (HVST; n = 11, 3 sets), or control group (n = 12). Training groups performed 12 weeks of supervised strength exercises, 15 maximum repetitions, five times a week, 20 minutes for LVST and 40 minutes for HVST for each training session. Measurements included body composition, strength and muscle volume, as well as blood analysis (glucose, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein) pre- and post-training. The HVST and LVST improved the one-repetition maximum knee extension strength (p < 0.001), maximal dynamic strength (p < 0.001), and muscle volume (p = 0.048). Post-training triglyceride was lower in HVST when compared to LVST and the control group (p = 0.047). Even though they present the same neuromuscular and morphological adaptations in postmenopausal women, the HVST is more effective than LVST in improving the lipid profile of postmenopausal woman, and can be considered as an ideal program of intervention to reverse changes in lipid metabolism commonly found in this group. Copyright (C) 2014, The Society of Chinese Scholars on Exercise Physiology and Fitness. Published by Elsevier (Singapore) Pte Ltd. All rights reserved.

Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial

The present study investigates the effects of vitamin D on muscle function in postmenopausal women. It has been shown that vitamin D supplementation in postmenopausal women with hypovitaminosis D provides significant protective factor against sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass. We aimed to evaluate the effect of supplementation of vitamin D (VITD) alone on muscle function in younger postmenopausal women. In this double-blind, placebo-controlled clinical trial, 160 Brazilian postmenopausal women were randomized into two groups: VITD group consisting of patients receiving vitamin D3 1000 IU/day orally (n = 80) or placebo group (n = 80). Women with amenorrhea for more than 12 months and age 50-65 years, with a history of falls (previous 12 months), were included. The intervention time was 9 months, with assessments at two points, start and end. Lean mass was estimated by total-body dual-energy X-ray absorptiometry (DXA) and muscle strength by handgrip strength and chair rising test. The plasma concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by high-performance liquid chromatography (HPLC). Statistical analysis was by intention to treat (ITT), using ANOVA, Student's t test, and Tukey's test. After 9 months, average values of 25(OH)D increased from 15.0 ± 7.5 to 27.5 ± 10.4 ng/ml (+45.4 %) in the VITD group and decreased from 16.9 ± 6.7 to 13.8 ± 6.0 ng/ml (-18.5 %) in the placebo group (p < 0.001). In the VITD group, there was significant increase in muscle strength (+25.3 %) of the lower limbs by chair rising test (p = 0.036). In women in the placebo group, there was considerable loss (-6.8 %) in the lean mass (p = 0.030). The supplementation of vitamin D alone in postmenopausal women provided significant protective factor against the occurrence of sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass.

Balance and ankle muscle strength predict spatiotemporal gait parameters in individuals with diabetic peripheral neuropathy

The aims of this study were to evaluate aspects of balance, ankle muscle strength and spatiotemporal gait parameters in individuals with diabetic peripheral neuropathy (DPN) and verify whether deficits in spatiotemporal gait parameters were associated with ankle muscle strength and balance performance. Thirty individuals with DPN and 30 control individuals have participated. Spatiotemporal gait parameters were evaluated by measuring the time to walk a set distance during self-selected and maximal walking speeds. Functional mobility and balance performance were assessed using the Functional Reach and the Time Up and Go tests. Ankle isometric muscle strength was assessed with a handheld digital dynamometer. Analyses of variance were employed to verify possible differences between groups and conditions. Multiple linear regression analysis was employed to uncover possible predictors of gait deficits. Gait spatiotemporal, functional mobility, balance performance and ankle muscle strength were affected in individuals with DPN. The Time Up and Go test performance and ankle muscle isometric strength were associated to spatiotemporal gait changes, especially during maximal walking speed condition. Functional mobility and balance performance are damaged in DPN and balance performance and ankle muscle strength can be used to predict spatiotemporal gait parameters in individuals with DPN.

Neuromuscular efficiency of the vastus lateralis and biceps femoris muscles in individuals with anterior cruciate ligament injuries

To analyze strength and integrated electromyography (IEMG) data in order to determine the neuromuscular efficiency (NME) of the vastus lateralis (VL) and biceps femoris (BF) muscles in patients with anterior cruciate ligament (ACL) injuries, during the preoperative and postoperative periods; and to compare the injured limb at these two times, using the non-operated limb as a control. EMG data and BF and VL strength data were collected during three maximum isometric contractions in knee flexion and extension movements. The assessment protocol was applied before the operation and two months after the operation, and the NME of the BF and VL muscles was obtained. There was no difference in the NME of the VL muscle from before to after the operation. On the other hand, the NME of the BF in the non-operated limb was found to have increased, two months after the surgery. The NME provides a good estimate of muscle function because it is directly related to muscle strength and capacity for activation. However, the results indicated that two months after the ACL reconstruction procedure, at the time when loading in the open kinetic chain within rehabilitation protocols is usually started, the neuromuscular efficiency of the VL and BF had still not been reestablished.