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This study compared the effects of concentric and eccentric training on neuromuscular adaptations in young subjects. Twenty-two men and women were assigned to one of two groups: concentric (CON, n = 11) and eccentric (ECC, n = 11) training. Training consisted of 6 weeks of isokinetic exercise, performed twice weekly, starting with two sets of eight repetitions, and progressing to five sets of 10 repetitions. Subjects were tested in strength variables [concentric, eccentric, and isometric peak torque (PT), and rate of force development (RFD)], muscle conduction velocity (CV), neuromuscular activity, vastus lateralis (VL) muscle thickness, and echo intensity as determined by ultrasonography. There were similar increases in the concentric and eccentric PTs in both the CON and ECC groups (P < 0.01), but only the ECC group showed an increase in isometric PT (P < 0.001). Similarly, both groups exhibited increased VL muscle thickness, CV, and RFD, and reduced VL echo intensity (P < 0.05). Significant correlations were observed among the relative changes in the neuromuscular outcomes and training variables (e.g., total work, average PT) (r = 0.68-0.75, P < 0.05). The results showed that both training types similarly improved dynamic PT, CV, RFD, and muscle thickness and quality during the early weeks of training. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to investigate the sensitivity of new surface electromyography (sEMG) indices based on the discrete wavelet transform to estimate acute exercise-induced changes on muscle power output during a dynamic fatiguing protocol. Fifteen trained subjects performed five sets consisting of 10 leg press, with 2min rest between sets. sEMG was recorded from vastus medialis (VM) muscle. Several surface electromyographic parameters were computed. These were: mean rectified voltage (MRV), median spectral frequency (F med), Dimitrov spectral index of muscle fatigue (FInsm5), as well as five other parameters obtained from the stationary wavelet transform (SWT) as ratios between different scales. The new wavelet indices showed better accuracy to map changes in muscle power output during the fatiguing protocol. Moreover, the new wavelet indices as a single parameter predictor accounted for 46.6% of the performance variance of changes in muscle power and the log-FInsm5 and MRV as a two-factor combination predictor accounted for 49.8%. On the other hand, the new wavelet indices proposed, showed the highest robustness in presence of additive white Gaussian noise for different signal to noise ratios (SNRs). The sEMG wavelet indices proposed may be a useful tool to map changes in muscle power output during dynamic high-loading fatiguing task. [ABSTRACT FROM AUTHOR]

Abstract: This study compares a non-linear (neural network) and a linear (linear regression) power mapping using a set of features of the surface electromyogram recorded from the vastus medialis and lateralis muscles. Fifteen healthy participants performed 5 sets of 10 repetitions leg press using the individual maximum load corresponding what they could perform 10 times (10RM) with 120s of rest between them. The following sEMG variables were computed from each extension contraction and used as inputs to both approaches: mean average value (MAV), median frequency (Fmed), the spectral parameter proposed by Dimitrov (FInsm5), average (over the observation interval) of the instantaneous mean frequency obtained from a Choi–Williams distribution (MFM), and wavelet indices ratio between moments at different scales (WIRM1551, WIRM1M51, WIRM1522, WIRE51, and WIRW51). The non-linear mapping (neural network) provided higher correlation coefficients and signal-to-noise ratios values (although not significantly different) between the actual and the estimated changes of power compared to linear mapping (linear regression) using the sEMG variables alone and a combination of WIRW51 and MFM (obtained by a stepwise multiple linear regression). In conclusion, non-linear mapping of force loss during dynamic knee extension exercise showed higher signal-to-noise ratio and correlation coefficients between the actual and estimated power output compared to linear mapping. However, since no significant differences were observed between linear and non-linear approaches, both were equally valid to estimate changes in peak power during fatiguing repetitive leg extension exercise. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to examine acute exercise-induced changes on muscle power output and surface electromyography (sEMG) parameters (amplitude and spectral indices of muscle fatigue) during a dynamic fatiguing protocol. Fifteen trained subjects performed five sets consisting of 10 leg presses (10RM), with 2min rest between sets. Surface electromyography was recorded from vastus medialis (VM) and lateralis (VL) and biceps femoris (BF) muscles. A number of EMG-based parameters were compared for estimation accuracy and sensitivity to detect peripheral muscle fatigue. These were: Mean Average Voltage, median spectral frequency, Dimitrov spectral index of muscle fatigue (FInsm5), as well as other parameters obtained from a time–frequency analysis (Choi–Williams distributions) such as mean and variance of the instantaneous frequency and frequency variance. The log FInsm5 as a single parameter predictor accounted for 37% of the performance variance of changes in muscle power and the log FInsm5 and MFM as a two factor combination predictor accounted for 44%. Peripheral impairments assessed by sEMG spectral index FInsm5 may be a relevant factor involved in the loss of power output after dynamic high-loading fatiguing task. [Copyright &y& Elsevier]

Abstract: We analyzed the discriminative capacity of several risk factors for elder abuse and neglect, in order to identify what characteristics distinguish between caregivers with a high or low risk of abuse and neglect. Forty-five caregivers of relatives with dementia participated. The combination of caregiving impact, frequency of aggressive behaviors by care-recipients, stress related to provocative and aggressive behaviors, the frequency of provocative behaviors, interpersonal burden, autoefficiency expectations, quantity of help received and depression classify correctly as risk factors in 90.9% of the cases. This study permits us to identify what characteristics distinguish between caregivers with a high or low risk of abuse and neglect and caregivers. [Copyright &y& Elsevier]

Progress in micro-electromechanical systems has turned inertial sensor units (IUs) into a suitable tool for vertical jumping evaluation. In total, 9 men and 8 women were recruited for this study. Three types of vertical jumping tests were evaluated in order to determine if the data provided by an IU placed at the lumbar spine could reliably assess jumping biomechanics and to examine the validity of the IU compared with force plate platform recordings. Robust correlation levels of the IU-based jumping biomechanical evaluation with respect to the force plate across the entire analysed jumping battery were found. In this sense, significant and extremely large correlations were found when raw data of both IU and force plate-derived normalised force–time curves were compared. Furthermore, significant and mainly moderate correlation levels were also found between both instruments when isolated resultant forces’ peak values of predefined jumping phases of each manoeuvre were analysed. However, Bland and Altman graphical representation demonstrated a systematic error in the distribution of the data points within the mean ±1.96 SD intervals. Using IUs, several biomechanical variables such as the resultant force–time curve patterns of the three different vertical jumps analysed were reliably measured. [ABSTRACT FROM PUBLISHER]

Among the diverse group of interventions developed to help dementia family caregivers cognitive-behavioural approaches show especially promising results. Objectives: This study describes a cognitive-behavioural group intervention aimed principally at the modification of dysfunctional thoughts associated with caregiving (MDTC). The efficacy of the MDTC intervention in reducing caregivers' depressive symptomatology, together with the frequency and appraisal of problem behaviours, is compared to that of a waiting-list control group (WL). Furthermore, the potential mediating role of the dysfunctional thoughts in the relationship between this intervention and caregivers' depressive symptomatology is analyzed. Of the 74 dementia caregivers who were randomized to one of two conditions (MDTC and WL), 39 completed the post-intervention assessment. Statistical analyses were performed on an intention-to-treat basis, using last observation carried forward. The results reveal that the MDTC intervention is successful in reducing caregivers' level of depressive symptomatology and dysfunctional thoughts about caregiving, as well as in modifying their appraisal of their relative's problem behaviours. Furthermore, a mediating role for dysfunctional thoughts was found in the relationship between the MDTC intervention and levels of depressive symptomatology. The relevance of addressing dysfunctional thoughts and cognitive distortions in group interventions with caregivers is highlighted. [ABSTRACT FROM AUTHOR]

The cognitive correlates of affect intensity, together with the relationships between this variable and socio-demographic and outcome variables such as, respectively, age and anxiety remain understudied. This work analyzes age differences in affect intensity and in two types of cognitive coping strategies in threatening situations: vigilance and distraction. Also, the relationship between this two variables and their association with the level of anxiety is explored. Fifty five younger and 51 older subjects (aged 60 and more) participated in the study. The results revealed significant age differences in the assessed variables, as well as differential interrelationships between them in the 2 age groups. Also, affect intensity and cognitive coping appear to be more related to anxiety in the older subjects group. The relevance of age in the analysis of the relationships between psychological construct is highlighted. [ABSTRACT FROM AUTHOR]

Familism has been pointed out as a key value in Hispanic culture that may or may not be associated with caregiver distress. Although groups included in the Hispanic identity have many common features, differences between Hispanic sub-groups in the relationship of familism with burden and depressive symptoms remain unexplored. The association of familism with burden and depressive symptomatology was examined in 48 Hispanic dementia caregivers from Los Angeles (CA, USA) and 60 from Madrid (Spain) through path analyses. Burden and depressive symptomatology were positively and significantly related in both samples. Familism was significantly correlated with lesser burden in the USA Hispanic caregiver sample, but with higher levels of depressive symptoms in the Spanish sample. Significant differences between Hispanic samples were found in the relationship between familism, burden, and depression, denoting the importance of specific cultural contexts influencing dementia caregiving in Hispanics. [ABSTRACT FROM AUTHOR]

Analyzes the characteristics of the phenomenon of worry in old age. Differential characteristics of worry in the elderly according to severity of anxiety; Discriminative ability of different DSM-IV criteria for generalized anxiety disorder to reveal the presence of the disorder; Suggestion that the potential of a specific worry to affect daily well-being and quality of life is strongly related to the presence of a disorder.