BackgroundContemporary theories of motor control propose that motor planning involves the prediction of the consequences of actions. These predictions include the associated costs as well as the rewarding nature of movements’ outcomes. Within the estimation of these costs and rewards would lie the valence, that is, the pleasantness or unpleasantness of a given stimulus with which one is about to interact. The aim of this study was to test if motor preparation encompasses valence.Methodology/Principal FindingsThe readiness potential, an electrophysiological marker of motor preparation, was recorded before the grasping of pleasant, neutral and unpleasant stimuli. Items used were balanced in weight and placed inside transparent cylinders to prompt a similar grip among trials. Compared with neutral stimuli, the grasping of pleasant stimuli was preceded by a readiness potential of lower amplitude, whereas that of unpleasant stimuli was associated with a readiness potential of higher amplitude.Conclusions/SignificanceWe show for the first time that the sensorimotor cortex activity preceding the grasping of a stimulus is affected by its valence. Smaller readiness potential amplitudes found for pleasant stimuli could imply in the recruitment of pre-set motor repertoires, whereas higher amplitudes found for unpleasant stimuli would emerge from a discrepancy between the required action and their aversiveness. Our results indicate that the prediction of action outcomes encompasses an estimate of the valence of a stimulus with which one is about to interact.

Evolutionary theories posit that emotions prime organisms for action. This study examined whether corticospinal excitability (CSE) is modulated by the emotional valence of a to-be-grasped stimulus. CSE was estimated based on the amplitude of motor evoked potentials (MEPs) elicited using transcranial magnetic stimulation (TMS) and recorded on the first dorsal interosseous (FDI) muscle. Participants were instructed to grasp (ACTION condition) or just look at (NO-ACTION condition) unpleasant, pleasant and neutral stimuli. TMS pulses were applied randomly at 500 or 250 ms before a go signal. MEP amplitudes were normalized within condition by computing a ratio for the emotion-laden stimuli by reference to the neutral stimuli. A divergent valence effect was observed in the ACTION condition, where the CSE ratio was higher during the preparation to grasp unpleasant compared to pleasant stimuli. In addition, the CSE ratio was lower for pleasant stimuli during the ACTION condition compared to the NO-ACTION condition. Altogether, these results indicate that motor preparation is selectively modulated by the valence of the stimulus to be grasped. The lower CSE for pleasant stimuli may result from the need to refrain from executing an imminent action.

Background: One of the most disabling problems in Parkinson disease (PD) is gait impairment. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), have been introduced as a therapeutic alternative for coping with PD motor problems. However, the effects of tDCS on gait performance in PD have not yet been fully established. Therefore, the main objective of this study was to evaluate whether a single session of tDCS modifies gait kinematics in individuals with PD. Methods: Twenty-one individuals with PD were included in this randomized, double-blinded, sham-controlled design study. They were randomly allocated in one real (N = 8) or sham (N = 9) tDCS group. Real tDCS comprises a 2-mA anodic current applied over 15 minutes in the supplementary motor area and medial areas of the primary motor cortices through a bipolar electrode montage. Gait kinematics and the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) were assessed before and immediately after a single stimulation session. Pre- minus poststimulation (Δ) values were computed and compared through a Mann-Whitney test. Data are shown as the median (lower, upper quartile). Results: There was a significant group difference with a large effect size for Δ values of gait cadence (P = .014, d = 0.87), indicating its reduction after anodic stimulation in the real (−0.28 [−1.16, 0.01] steps/s) compared with sham tDCS group (0.17 [0.00, 0.40] steps/s). No other significant effect was found. Conclusion: The findings of this study suggest that anodic tDCS administered in a single session improves gait cadence in PD individuals.

Background and Purpose The motor impairments related to gait and balance have a huge impact on the life of individuals with spinocerebellar ataxia (SCA). Here, the aim was to assess the possibility of retraining gait, improving cardiopulmonary capacity, and challenging balance during gait in SCA using a partial body weight support (BWS) and a treadmill. Also, the effects of this training over functionality and quality of life were investigated. Methods Eight SCA patients were engaged in the first stage of the study that focused on gait training and cardiovascular conditioning. From those, five took part in a second stage of the study centered on dynamic balance training during gait. The first and second stages lasted 8 and 10 weeks, respectively, both comprising sessions of 50 min (2 times per week). Results The results showed that gait training using partial BWS significantly increased gait performance, treadmill inclination, duration of exercise, and cardiopulmonary capacity in individuals with SCA. After the second stage, balance improvements were also found. Conclusion Combining gait training and challenging tasks to the postural control system in SCA individuals is viable, well tolerated by patients with SCA, and resulted in changes in capacity for walking and balance.

Objective: To correlate muscule performance, body composition, pain and joint function in elderly people with gonarthrosis. Method: 21 elderly patients were submitted to bioelectrical impedance analysis, dynamometry associated with electromyographic (EMG) evaluation of isometric knee extension, in addition to pain assessment by the Numeric Pain Intensity Scale and function assessment, by the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis (OA) questionnaire. Correlations were checked by the Pearson's correlation coefficient. Results: The sample characteristics were mean age 67.36 ± 4.21 years old, body fat percentage 40.57±6.15%, total WOMAC score 43.27 ± 16.32%, and maximum strength 19.95 ± 6.99 kgF. Pain during movement showed a statistical association with WOMAC physical activity domain (r = 0.47) and its general score (r = 0.51); pain intensity at night presented association with WOMAC stiffness domain (r = 0.55), in addition to the negative correlation with the slope values of the Medium Frequency of the EMG signal (r = - 0.57). Conclusion: pain intensity is correlated to functional incapacity in elderly people with knee OA and to a greater expression of fatigue in EMG signal. Levels of Evidence III, Study of non consecutive patients

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[Purpose] Spinocerebellar ataxia consists of a group of autosomal dominant disorders that cause progressive degeneration, mainly in the cerebellum and its connections. Falls, which are a significant concern of this condition, reduce patients’ mobility, deteriorate their health and have physical and social consequences. The aim of this study was to test the effectiveness of a modified protocol for improving balance and diminishing the fall risk of spinocerebellar ataxia patients exclusively. [Subjects and Methods] Exercises aiming to improve static and dynamic balance, whole body movements, measures to prevent falls and falling strategies were performed twice per week for four weeks by 11 spinocerebellar ataxia patients. Balance was evaluated using the Berg Balance Scale. [Results] The results show that there was a significant increase in Berg Balance Scale scores after the interventions (Wilcoxon p=0.0034). [Conclusion] This study demonstrated that the modified protocol is effective at reducing the fall risk of spinocerebellar ataxia patients. This protocol may be a useful option for appropriately coping with falls caused by spinocerebellar ataxia.

[Purpose] Complaint of pain is common in computer workers, encouraging the investigation of pain-related workplace factors. This study investigated the relationship among work-related characteristics, psychosocial factors, and pain among computer workers from a university center. [Subjects and Methods] Fifteen subjects (median age, 32.0 years; interquartile range, 26.8–34.5 years) were subjected to measurement of bioelectrical impedance; photogrammetry; workplace measurements; and pain complaint, quality of life, and motivation questionnaires. [Results] The low back was the most prevalent region of complaint (76.9%). The number of body regions for which subjects complained of pain was greater in the no rest breaks group, which also presented higher prevalences of neck (62.5%) and low back (100%) pain. There were also observed associations between neck complaint and quality of life; neck complaint and head protrusion; wrist complaint and shoulder angle; and use of a chair back and thoracic pain. [Conclusion] Complaint of pain was associated with no short rest breaks, no use of a chair back, poor quality of life, high head protrusion, and shoulder angle while using the mouse of a computer.