Predictors of Acquisition of Competitive Employment for People Enrolled in Supported Employment Programs.

This study aims at assessing the relative contribution of employment specialist competencies working in supported employment (SE) programs and client variables in determining the likelihood of obtaining competitive employment. A total of 489 persons with a severe mental illness and 97 employment specialists working in 24 SE programs across three Canadian provinces were included in the study. Overall, 43% of the sample obtained competitive work. Both client variables and employment specialist competencies, while controlling for the quality of SE programs implementation, predicted job acquisition. Multilevel analyses further indicated that younger client age, shorter duration of unemployment, and client use of job search strategies, as well as the working alliance perceived by the employment specialist, were the strongest predictors of competitive employment for people with severe mental illness, with 51% of variance explained. For people with severe mental illness seeking employment, active job search behaviors, relational abilities, and employment specialist competencies are central contributors to acquisition of competitive employment.

Controlling for out-of-plane lumbar moments during unidirectional trunk efforts: learning and reliability issues related to trunk muscle activation estimates.

To assess the electromyographic (EMG) activation of trunk muscle during exertions performed in one primary plane (sagittal, frontal, transverse), we previously proposed a protocol allowing minimizing out-of-plane efforts (coupled moments - CMs) with the use of a static dynamometer combined with a visual feedback system. The aims of this study were to go further by testing motor learning and reliability issues related to such a protocol. Three identical sessions were conducted, where maximal voluntary contractions and submaximal ramp contractions were performed in six different directions while standing in the dynamometer. Two feedback conditions were tested, the simple 1D-feedback in the primary plane and the full 3D-feedback in all planes simultaneously. Surface EMG signals were collected from back and abdominal muscles and EMG amplitude and CMs were computed during the ramp contractions. Providing a 3D feedback to minimize CMs did not improve EMG reliability or in other words, did not reduce the within-subject variability. Providing three assessment days had practically no effect (no learning) on CMs and EMG variables. Overall, the reliability of EMG was at best moderate. However, although this limits its use on an individual basis, it still allows within- and between-group comparisons for research applications.

Offering proper feedback to control for out-of-plane lumbar moments influences the activity of trunk muscles during unidirectional isometric trunk exertions.

The assessment of trunk muscle activation and coordination using dynamometric measurements made in one anatomical plane has hardly minimized the production of out-of-plane coupled moments (CMs). This absence of control may add much variability in moment component partition as well as in recorded muscle activation. The aim of the study was to assess whether providing these CMs as visual feedback efficiently reduces them and whether this feedback influences trunk muscle activation. Twenty men performed five 5-s static ramp submaximal contractions, ranging from 0% to 55% of the maximal voluntary contraction (MVC), in six different directions while standing in a static dynamometer measuring L5/S1 moments. For each direction, four feedback conditions were offered, ranging from simple 1D-feedback in the primary plane of exertion, to full 3D-feedback. Surface electromyographic signals were collected for eight back and six abdominal muscles. Muscle activation amplitudes and CMs were extracted at each 10% force level from 10% to 50% maximum voluntary contraction (MVC). Providing 3D-feedback significantly reduced the CMs, at 50% MVC, by about 1-6%, 1-8% and 2-10% MVC in the sagittal, frontal and transverse planes, respectively. Providing 3D-feedback produced relatively small systematic effects (2-7%) on trunk muscle activation. However, the subjects responded differently to adequately control the coupled moments, leading in some cases to relatively high inter-individual differences in muscle activation. Interestingly, the statistical differences, and size of the effects, were mainly observed when the primary exertions were performed in the frontal and transverse planes. The implications of these findings are discussed.