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.

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.

Risk factors for non-specific low back pain in older people: a systematic review with meta-analysis.

PURPOSE: To conduct a systematic review about risk factors associated with non-specific low back pain (LBP) in older people. METHODS: The study protocol was prospectively registered with Prospero (CRD42020191619). This systematic review with meta-analysis included cohort studies that investigated risk factors for LBP in older people. The following databases were searched up to 12 December 2020: MEDLINE (Ovid), Embase, CINAHL, SCOPUS and Web of Science. Two independent reviewers appraised methodological quality using the Critical Appraisal Checklist for Cohort Studies instrument. RESULTS: We identified 3939 potentially relevant publications. After removing duplicates, screening title, and abstracts, we assessed 86 publications in full text. We included the remaining 11 publications for analysis. There is strong evidence that depressive symptoms are a risk of reporting future back pain onset (I2 = 52,7%, Odds ratio 1.4, CI 1.28-1.53). CONCLUSION: Depressive symptoms are a risk factor for LBP in older people. Due to the limitations of the literature, the role of some risk factors remains unclear. An additional high-quality prospective cohort is needed to better elucidate these relationships.