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Gait and balance impairment is common in multiple sclerosis (MS), often leading to walking aids need. Rehabilitation is the most common and effective approach to tackle the burden of these symptoms, but less attention is given to the correct use of an assistive device for ambulation. Here, we aimed to maximise the effect of a rehabilitation program including walking aid training with a sensorized crutch in people with MS (PwMS). 24 PwMS (15 females, age=57.8±9.8 years, all EDSS=6) underwent a 20-session rehabilitation program focusing on gait, balance, and proper assistive device use. The experimental group (FB_group, N=12) used a crutch with real-time feedback based on user support load, whilst the control group (NOFB_group, N=12) used a standard crutch. Assessment included Timed 25 Foot Walk (T25FW), Timed Up and Go (TUG) and Modified Fatigue Impact Scale (MFIS). Moreover, functional Near-Infrared Spectroscopy (fNIRS) was used to investigate cortical activity during linear and curvilinear walking tasks. At baseline, no differences were found between groups concerning either clinical or neural evaluations. Following rehabilitation, we observed a reduction in fatigue perception in both groups (p=0.038). Moreover, FB_group performed better than NOFB_group in T25FW and TUG (p=0.028 and p=0.038, respectively). Further, after treatment, FB_group showed increased neural activity in areas involved in cognitive functions (Brodmann Areas-BA 9,10, p<0.01), multisensory integration and body representation (BA39, p=0.01) during both linear and curvilinear walking. Instead, NOFB_group showed increased activity in motor planning areas (BA 6,8, p<0.05). A significant difference was also found between groups in BA9 after treatment (FB_group>NOFBgroup, p=0.04). A 20-session rehabilitation period effectively reduces fatigue among PwMS. Moreover, a real-time feedback crutch seems to have a positive impact on walking ability. This might be due to a feedback-induced increased attention focusing on the assistive device, as suggested by the fNIRS results. [ABSTRACT FROM AUTHOR]

Concentric and eccentric contractions show different patterns of neural activity at both peripheral and cortical levels, which are thought to influence the perception of action properties such as the weight of objects moved by others. The aim of this study was to investigate how the type of muscle contraction influences weight estimation during action observation.Forty‐eight volunteers completed the Main experiment and the Control experiment. In the Main experiment, they performed a weight discrimination video task in which they watched videos of an actor moving two objects, a comparison, and a reference box, executing concentric or eccentric contractions and they had to indicate which box was the heaviest. Sensitivity analysis and psychometric functions were used to analyse the data. In the Control experiment, observers judged the actor's effort in moving the boxes.The results of the Main experiment showed that the weight discrimination sensitivity was higher in the eccentric condition for the light boxes. Conversely, for the heaviest boxes, discrimination sensitivity was higher in the concentric condition. These results were confirmed by the psychometric function analysis. The control experiment showed that the perceived difference in effort between the comparison and reference stimuli was greater in the eccentric than in the concentric condition for light stimuli.These results showed that the ability to evaluate the weight of the object involved in the observed action was influenced by the type of contraction and the amount of weight. The effort attributed to the actor influenced the observer's perception. [ABSTRACT FROM AUTHOR]

Significance: Motion artifacts are a notorious challenge in the functional near-infrared spectroscopy (fNIRS) field. However, little is known about how to deal with them in resting-state data., Aim: We assessed the impact of motion artifact correction approaches on assessing functional connectivity, using semi-simulated datasets with different percentages and types of motion artifact contamination., Approach: Thirty-five healthy adults underwent a 15-min resting-state acquisition. Semi-simulated datasets were generated by adding spike-like and/or baseline-shift motion artifacts to the real dataset. Fifteen pipelines, employing various correction approaches, were applied to each dataset, and the group correlation matrix was computed. Three metrics were used to test the performance of each approach., Results: When motion artifact contamination was low, various correction approaches were effective. However, with increased contamination, only a few pipelines were reliable. For datasets mostly free of baseline-shift artifacts, discarding contaminated frames after pre-processing was optimal. Conversely, when both spike and baseline-shift artifacts were present, discarding contaminated frames before pre-processing yielded the best results., Conclusions: This study emphasizes the need for customized motion correction approaches as the effectiveness varies with the specific type and amount of motion artifacts present., (© 2024 The Authors.)