Differential effects of skilled reaching training on the temporal and spatial organization of somatosensory input to cortical and striatal motor circuits

It has been hypothesized that in order to perform sensorimotor transformations efficiently, somatosensory information being fed back to a particular motor circuit is organized in accordance with the mechanical loading patterns of the skin that results from the motor activity generated by that circuit. Rearrangements of sensory information to different motor circuits could in this respect constitute a key component of sensorimotor learning. We have here explored if the organization of tactile input from the plantar forepaw of the rat to cortical and striatal circuits is affected by a period of extensive sensorimotor training in a skilled reaching and grasping task. Our data show that the representation of tactile stimuli in terms of both temporal and spatial response patterns changes as a consequence of the training, and that spatial changes particularly involve the primary motor cortex. Based on the observed reorganization, we propose that reshaping of the spatiotemporal representation of the tactile afference to motor circuits is an integral component of the learning process that underlies skill-acquisition in reaching and grasping.

Back to feedback: aberrant sensorimotor control in music performance under pressure

Precisely timed production of dexterous actions is often destabilized in anxiogenic situations. Previous studies demonstrated that cognitive functions such as attention and working memory as well as autonomic nervous functions are susceptible to psychological stress in skillful performance while playing sports or musical instruments. However, it is not known whether the degradation of sensorimotor functions underlies such a compromise of skillful performance due to psychophysiological distress. Here, we addressed this issue through a set of behavioral experiments. After artificially delaying the timing of tone production while playing the piano, the local tempo was abnormally disrupted only under pressure. The results suggest that psychological stress degraded the temporal stability of movement control due to an abnormal increase in feedback gain. A learning experiment further demonstrated that the temporal instability of auditory-motor control under pressure was alleviated after practicing piano while ignoring delayed auditory feedback but not after practicing while compensating for the delayed feedback. Together, these findings suggest an abnormal transition from feedforward to feedback control in expert piano performance with psychological stress, which can be mitigated through specialized sensorimotor training that involves piano practice while volitionally ignoring the artificially delayed provision of auditory feedback.

Physiotherapist-led rehabilitation for patients with chronic musculoskeletal pain: interventions and promising long-term outcomes

Background There is no consensus on best content, set-up, category of involved healthcare professionals or duration of rehabilitation-programs for patients with chronic musculoskeletal pain, and outcomes show varying results. Individual care regimes for sub-groups of patients have been proposed. Aim To describe the type of interventions used in a physiotherapist-led, rehabilitation-program for patients with chronic musculoskeletal pain, refractory to preceding treatments. A second aim was to report clinical outcomes at 1-year follow-up after the intervention period. Methods All patients referred to physiotherapist within a specialist pain-unit due to being refractory to preceding treatments, and deemed fit to undergo physiotherapy-based, individualized rehabilitation during 2014–2018 were consecutively included and followed-up 1 year after ending the program. The inclusion was based on structured ‘clinical reasoning’ using the referral, examination and on patient-relevant outcome measures. The individual interventions, recorded according to a manual used when reading the patients’ medical records, were described. Primary outcomes were clinical results of perceived pain, disability and overall health at start, discharge and 1 year after discharge. Results In total, 274 patients (mean age 42 years, 71% women) were included, suffering from chronic, severe, musculoskeletal pain (VAS median 7/10, duration median 2.8 years) and moderate disability. The most frequent interventions were education, sensorimotor training, physical activity-advice and interventions for structures/functions (for example manual techniques, stretching) for a median of nine sessions during five months. Despite refractory to preceding treatments, 45% of the patients rated clinically important improvements on pain, 61% on disability and 50% on overall health at discharge and the figures were similar at 1-year follow-up. Conclusions A physiotherapist-led, one-to-one, rehabilitation-program of median nine sessions during five months, combining individualized education, sensorimotor training, physical activity-advice and interventions for structures/functions rendered clinically relevant improvements on pain, disability and overall health in half of the patients at 1-year follow-up. Since the cohort consisted of patients refractory to preceding treatments, we believe that these results warrant further studies to identify the subgroups of patients with chronic musculoskeletal pain that will improve from new, distinctive, resource-effective rehabilitation-programs involving individualized rehabilitation.

Effect of Incorporating Short-Foot Exercises in the Balance Rehabilitation of Flat Foot: A Randomized Controlled Trial

Effective balance rehabilitation is essential to address flat foot (pes planus) which is closely associated with reduced postural stability. Although sensorimotor training (SMT) and short-foot exercise (SFE) have been effective for improving postural stability, the combined effects of SMT with SFE have not been evaluated in previous studies. The aim of this study was to compare the lone versus combined effects of SMT with SFE on postural stability among participants with flat foot. This was a single-blinded, randomized controlled trial. A total of 32 flat-footed participants were included in the study (14 males and 18 females) and assigned to the SMT combined with SFE group and SMT alone group. All participants underwent 18 sessions of the SMT program three times a week for six weeks. Static balance, dynamic balance, and the Hmax/Mmax ratio were compared before and after the interventions. Static and dynamic balance significantly increased in the SMT combined with SFE group compared with the SMT alone group. However, the Hmax/Mmax ratio was not significantly different between the two groups. Therefore, this study confirms that the combination of SMT and SFE is superior to SMT alone to improve postural balance control in flat-footed patients in clinical settings.

Promoting neuroplasticity and neuropsychological functioning in frailty through an app-based sensorimotor training: study protocol for a randomized trial

Background Frailty is characterized by an age-related decline in multiple physiological systems, leading to a high vulnerability to stressors, adverse health outcomes, and low quality of life. Neuroscientific models of pathological aging emphasize the loss of sensorimotor stimulation and reduced neuromodulatory capacities as core processes in age-related cognitive and bodily decline, which may be associated with maladaptive plastic changes in the brain. We plan to increase sensorimotor stimulation in frail persons through a newly developed app-based training program and link the training trials to biological and psychological correlates of age-associated vulnerability and health indices. Methods We will conduct a randomized trial, applying an app-based sensorimotor home training (N = 30) in people suffering from frailty. An app-based relaxation training will serve as an active control condition (N = 30). Both interventions will last for 90 days each. The sensorimotor training includes unimodal and multimodal sensory discrimination tasks in the visual, auditory, and tactile domain, as well as sensorimotor precision tasks. The tasks will be implemented using an adaptive training algorithm and enriched with motivational components embedded in a virtual training environment. We expect a pre-post reduction of frailty status and associated functional decline related to refinement of representational maps within the sensorimotor system and improved sensorimotor function such as extremity function. Secondary analyses will study the influence of BDNF genotype as moderating variable. Additional outcomes will include measures of perceptual and cognitive functioning, quality of life as well as BDNF serum levels. Measurements will take place before training (baseline), after 60 days (assessment 1), and at the end of the training after 90 days (assessment 2). Discussion In our randomized trial, we aim to characterize a multidimensional concept of frailty and to target maladaptive behaviors and neuroplasticity using an app-based sensorimotor training. This type of intervention might provide further knowledge and new possibilities for preventing decline and preserving function in older adults. Trial registration ClinicalTrials.gov NCT03666039. Registered 11 September 2018 – Retrospectively registered. Protocol version: Version 4 revised (issue date: 19 May 2021).