What is the influence of biomechanical variables on the Y balance test performance in recreational runners?

BACKGROUND: Asymmetries and poor Y balance test (YBT) performance are associated with an increased risk of injuries in athletes. The aim of this study was to investigate the association between YBT performance with biomechanical variables in runners. METHODS: The runners underwent the YBT, followed by the assessment of center of pressure, plank position, muscle strength (MS) of hip flexors, extensors, abductors, and external rotators, knee extensors, ankle dorsiflexion range of motion (ROM), Q angle, forefoot alignment, and passive hip internal rotation. Associations between variables were examined using multiple linear regression models with the Bayesian Information Criterion. RESULTS: 122 cases were analyzed. The R2 values were 0.38; 0.05; 0.06; and 0.15 for the anterior, posteromedial, posterolateral and composite directions models, respectively. The anterior reach in the YBT was associated with ankle dorsiflexion ROM [Sß 95%IC: 0.43 (0.32-0.55)], passive hip internal rotation [Sß 95%IC: 0.35 (0.24-0.47)], MS of the hip extensors [Sß 95%IC: 0.19 (0.07-0.31)] and forefoot alignment [Sß 95%IC: 0.14 (-0.25-0.02)]. The posteromedial and posterolateral reach were associated with MS of the hip flexors [Sß 95%IC: 0.23 (0.09-0.37) and 0.24 (0.11-0.38)], respectively. The composite score was associated with MS of the hip flexors [Sß 95%IC: 0.31 (0.18-0.45)], ankle dorsiflexion ROM [Sß 95%IC: 0.24 (0.10-0.37)] and Q angle [Sß 95%IC: 0.18 (0.04-0.31)]. CONCLUSION: YBT performance in different directions demonstrated specific associations with key biomechanical factors.

Prevalence of pelvic floor disorders and the associated quality of life among institutionalized and noninstitutionalized elderly women: A cross-sectional study.

Background: An increase in life expectancy has led to an increased elderly population. In turn, this aging population is more likely to develop health conditions, such as pelvic floor disorders (PFDs). This study aimed to assess the prevalence of these disorders and the associated quality of life in institutionalized and noninstitutionalized elderly women. Materials and methods: A cross-sectional study was conducted with 80 female participants older than 60 years, divided into 2 groups: institutionalized and noninstitutionalized participants. The Pelvic Floor Distress Inventory Short-Form and a sociodemographic questionnaire were used. A chi-squared test was used to assess the differences in prevalence between groups. Results: There was no statistically significant difference between the groups in the prevalence of PFDs or quality of life. In this study, the prevalence of PFDs was higher than that reported previously. In institutionalized women, a higher prevalence of PFDs and impaired quality of life were expected, although not observed. Conclusions: There was a higher prevalence of pelvic disorders and impaired quality of life due to these disorders in elderly women.

Effects of whole-body electromyostimulation on health indicators of older people: Systematic review and meta-analysis of randomized trials.

OBJECTIVE: to provide evidence for the effects of whole-body electromyostimulation (WB-EMS) on health-related outcomes compared to the effects of minimal or non-intervention for older people in the short/medium/long term. DATA SOURCES: seven databases (MEDLINE, Embase, CENTRAL, CINAHL, Scopus, SPORTDiscuss and Web of Science) were electronically searched in April 2020 and updated in March 2021. STUDY SELECTION: included studies were randomized controlled trials (RCTs) involving WB-EMS that assessed effects on health-related outcomes, risks and adverse events in older people (>60 years). DATA EXTRACTION: the following data were obtained: author and publication year, follow-up, detailed information of older characteristics, current parameters/intensity and outcomes. DATA SYNTHESIS: a random effects model was used with effect size reported as SMD. Statistical heterogeneity was assessed using the I2 test. RESULTS: 13 RCTs met the eligibility criteria. Meta-analysis found: large effects of WB-EMS on reducing sarcopenia Z-score (ES: 1.44[-2.02: 0.87] p= <.01) and improving isometric strength leg extensors (ES: 0.81[0.41: 1.21] p= <.01) at medium and long-term, respectively. Moderate effects of WB-EMS on improving handgrip strength (ES: 0.58[0.23: 0.92] p= <.01) and habitual gait speed (ES: 0.69[0.31: 1.07] p= <.01) at medium-term and improving appendicular skeletal muscle mass (ES:0.69 [0.30: 1.09] p= <.01) at long-term. Non-significant effect of WB-EMS on waist circumference (p = .17) and triglycerides (p = .20) at medium-term. Non-significant effects of WB-EMS on improving creatine kinase concentrations, C-reactive protein, and interleukin 6 at medium-term. CONCLUSIONS: This review provides further evidence for significant, moderate to large effect sizes of WB-EMS on sarcopenia, muscle mass and strength parameters, but not on waist circumference and triglycerides. SYSTEMATIC REVIEW REGISTRATION: PROSPERO database no. CRD42019134100.

Gain and coherence estimates between respiration and heart-rate: differences between inspiration and expiration.

The interaction of respiration and heart-rate variability (HRV), leading to respiratory sinus arrhythmia (RSA) and, in the inverse direction, cardioventilatory coupling has been subject of much study and controversy. A parametric linear feedback model can be used to study these interactions. In order to investigate differences between inspiratory and expiratory periods, we propose that models are estimated separately for each period, by finding least mean square estimates only over the desired signal segments. This approach was tested in simulated data and heart-rate and respiratory air flow signals recorded from 25 young healthy adults (13 men and 12 women), at rest, breathing spontaneously through a face mask for 5 min. The results show significant differences (p<0.05) between the estimates of coherence obtained from the whole recording, and the inspiration and expiration periods. Simple and causal coherence from respiration to HRV was higher during inspiration than expiration. The estimates of gain also differed significantly in the high frequency (HF) band (0.15-0.5Hz) between those obtained from the whole recording, and the inspiratory and expiratory periods. These results indicate that a single linear model fitted to the whole recording neglects potentially important differences between inspiration and expiration, and the current paper shows how such differences can be estimated, without the need to control breathing.

Influences of the extensor portion of the gluteus maximus muscle on pelvic tilt before and after the performance of a fatigue protocol.

INTRODUCTION: There is a lack of data in the literature for determining the influences of the extensor portion of the gluteus maximus muscle on pelvic tilting and, thus, on lumbar stability. OBJECTIVES: To assess the influences of the extensor portion of the gluteus maximus muscle on pelvic tilt. METHODS: Ten healthy young subjects were recruited, with a body mass index (BMI) below 24.9 kg/m(2) and leg length discrepancy below 1 cm. The BMI, pelvic perimeter and lower-limb lengths were assessed and, subsequently, the degrees of hemi-pelvic tilt and asymmetry between them were analyzed using lateral view photographs of the subjects in a standing position, using SAPO (Software for Postural Assessment). Next, fatigue was induced in the extensor portion of the gluteus maximus muscle on the dominant side, and after that the hemi-pelvic tilt and the asymmetry between the hemi-pelvises were reassessed. The Pearson r and Student t tests were conducted at the significance level of alpha=0.05. RESULTS: There were no significant correlations between the confounding variables and asymmetry of the hemi-pelvic angles. There were significant changes in the hemi-pelvic angle of the dominant side (t=3.760; p=0.004). CONCLUSIONS: Fatigue in the extensor portion of the gluteus maximus muscle can generate increases in the tilt angle of the ipsilateral pelvis.

Influência da porção extensora do músculo glúteo máximo sobre a inclinação da pelve antes e depois da realização de um protocolo de fadiga / Influences of the extensor portion of the gluteus maximus muscle on pelvic tilt before and after the performance of a fatigue protocol

INTRODUÇÃO: Há carência na literatura de dados que determinem qual a influência da porção extensora do músculo glúteo máximo na inclinação da pelve no plano sagital e, portanto, na estabilidade lombar. OBJETIVOS: Verificar a influência da porção extensora do músculo glúteo máximo sobre a inclinação da pelve. MÉTODOS: Foram recrutadas 10 voluntárias jovens, saudáveis, com índices de massa corpórea (IMC's) menores que 24,9 kg/m² e com dismetria real de membros inferiores (MMII) inferior a 1 cm. Foram avaliados o IMC, o perímetro pélvico e o comprimento dos MMII e, posteriormente, os graus de inclinação das hemipelves e a assimetria entre elas pela análise de uma fotografia em perfil ortostático usando o SAPO (Software para Avaliação Postural). Em seguida, a porção extensora do músculo glúteo máximo do lado dominante foi induzido à fadiga, após a qual foram determinadas novamente a inclinação das hemipelves e a assimetria entre elas. Testes de Pearson r e teste t de student foram realizados no nível de significância α=0,05. RESULTADOS: Não houve correlação entre as variáveis de confusão e a assimetria dos ângulos das hemipelves. O ângulo da hemipelve apresentou modificação significativa do lado dominante (t=3,760; p=0,004). CONCLUSÕES: A fadiga da porção extensora do músculo glúteo máximo pode gerar um aumento do ângulo de inclinação da pelve homolateral.

INTRODUCTION: There is a lack of data in the literature for determining the influences of the extensor portion of the gluteus maximus muscle on pelvic tilting and, thus, on lumbar stability. OBJECTIVES: To assess the influences of the extensor portion of the gluteus maximus muscle on pelvic tilt. METHODS: Ten healthy young subjects were recruited, with a body mass index (BMI) below 24.9 kg/m² and leg length discrepancy below 1 cm. The BMI, pelvic perimeter and lower-limb lengths were assessed and, subsequently, the degrees of hemi-pelvic tilt and asymmetry between them were analyzed using lateral view photographs of the subjects in a standing position, using SAPO (Software for Postural Assessment). Next, fatigue was induced in the extensor portion of the gluteus maximus muscle on the dominant side, and after that the hemi-pelvic tilt and the asymmetry between the hemi-pelvises were reassessed. The Pearson r and Student t tests were conducted at the significance level of α=0.05. RESULTS: There were no significant correlations between the confounding variables and asymmetry of the hemi-pelvic angles. There were significant changes in the hemi-pelvic angle of the dominant side (t=3.760; p=0.004). CONCLUSIONS: Fatigue in the extensor portion of the gluteus maximus muscle can generate increases in the tilt angle of the ipsilateral pelvis.