Knee osteoarthritis (KOA) is a prevalent and severe condition with versatile effects on human locomotion, including alterations in neuromuscular control. Muscle synergies are understood as functional low-dimensional building blocks within the neuromuscular organization. To examine alterations in muscle synergy patterns during locomotion tasks in the presence of KOA, 40 participants, including 20 with medial KOA (KL-Score ≥ 2), performed level walking, as well as ramp and stair ascent and descent trials at self-selected speeds. Sixteen-Channel bilateral surface electromyography (sEMG) and marker-based motion capture data were collected. Non-negative matrix factorization (NNMF) was applied to the sEMG data for muscle synergy extraction. During level walking and descending conditions, structural changes in muscle synergy composition were observed in the KOA affected limb when compared to the unaffected side and control group. Alterations included fewer, merged synergies with prolonged activation coefficients and a higher percentage of unclassifiable synergies. No major alterations were observed during ascending conditions. No significant differences in gait speed and stride length were observed. These results indicate that muscle synergy composition can be altered in the presence of KOA regardless of age and gait speed, but not during all forms of locomotion.

According to Fitts' law, an individual's speed-accuracy tradeoff is only related to the object's properties. According to previous research, the movement time to hit the current target can be affected by the target of different size on the previous trial where the Fitts' law task is affected by trial history. However, in a dyadic context, the question is whether there is still a trial-to-trial transfer across individuals. In this study, Experiment 1 was conducted to investigate whether the current trial would be affected by the previous trial performed by the partner in a dyadic task. The results showed trial-to-trial transfer between individuals was affected by the difficulty of the action. The current movement was only affected by the previous difficult trial but not simple task. In order to investigate whether observing only novel targets would affect the current movement, we conducted Experiment 2, which showed that observing the target was not sufficient to generate effect transfer between trials. These findings suggest that the goal-directed movement can be affected by the observation of others. In addition, the effect of trial-to-trial transfer between individuals was influenced by task difficulty, which proved this effect was not a simple imitation.

This study investigated ankle discriminative acuity and performance and measurement consistency for tests undertaken with different joint position exposure times (PETs). Twenty-four participants were tested using a novel Smartphone Proprioception for Ankle Navigation (SPAN) under four PETs, i.e., 0.25s, 0.5s, 0.75s and 1s, delivered in a random sequence, and then re-tested within one week. The results indicated a PET main effect ( = 10.12,  = 0.004, partial ƞ2 = 0.14), and limb preference main effect ( = 5.39,  = 0.03, partial ƞ2 = 0.19), without significant interactions ( > 0.05). Ankle proprioception improved with prolonged PET, with the non-dominant side outperforming the dominant side. A PET of 0.25s showed good to excellent reliability, with intraclass correlation coefficients (ICCs) of 0.897 (95%CI: 0.761, 0.955) and 0.885 (95%CI: 0.736, 0.951), with standard errors of measurements (SEM) between 0.030 and 0.035, and minimum detectable change at 90% (MDC) between 0.070 and 0.082, compared to poor to moderate reliability at the other three longer PETs (ICCs =0.352-0.736). The findings suggested the prolongation of PET can improve ankle proprioceptive performance but can amplify the inter-occasion variability, likely due to increased cognitive analysis with longer stimulus sampling. SPAN may thus be a cost-effective and accessible apparatus for clinical practice.

The aim of this study was to compare the kinematics of reaching tasks at different speeds between children with neonatal brachial plexus palsy (NBPP) and unaffected controls. This cross-sectional study included thirteen children with NBPP (10 ± 2 years old, of which six had upper Erb's palsy and seven had extended Erb's palsy) matched for age and sex with thirteen unaffected controls. Kinematic data were acquired using a Motion Monitor unit with a 3D motion tracking electromagnetic system (Liberty, Polhemus). Scapular, upper limb, and head were recorded during forward reaching tasks (hand on overhead ball and hand to head) and a backward reaching task (hand on the back pocket). The study revealed reduced shoulder flexion and extension in children with NBPP during hand on ball and on the back pocket tasks compared to unaffected controls. Limited elbow flexion was also observed in children with NBPP during the hand on ball and hand on the head tasks. During the hand to head task, children with NBPP presented increased head flexion compared to unaffected controls. Scapular kinematics analysis showed increased posterior tilt in children with NBPP during forward reaching (the hand on ball and hand to head tasks). In the backward reaching task (hand on the back pocket), the NBPP group exhibited reduced scapular external rotation compared to unaffected controls. These findings indicate distinct kinematics in the scapula, shoulder, elbow, and head during reaching tasks for children with NBPP compared to controls. Furthermore, different execution speeds did not alter the kinematic differences between the groups.

The aim of this study was to determine the effect of cognitive interference by using the Dual-Task (DT) paradigm on gait parameters according to sex, and age. Additionally, we aim to explore the relationship between Dual-Task-Cost (DTC), physical fitness, cognitive functioning, and weight status in schoolchildren. One hundred schoolchildren participated in this study (age = 8.83 ± 1.82 years). They were randomly assigned to Comfortable Linear Gait (CLG: gait in a straight path) or Complex Gait (CG: gait over obstacles) with and without interference. For CLG, boys and girls showed a reduction in gait speed ( < 0.001), cadence ( < 0.01), and step length ( < 0.001). In addition, double support time ( < 0.05) and cadence coefficient of variance (boys=  < 0.01; girls=  < 0.05) increased in the DT condition. In the CG, both sexes ( < 0.001) exhibited a worse execution time. There were significant effects on speed DTC between 8-9 vs. 10-11 years in CLG and 6-7 vs. 10-11 years in CGT ( < 0.05). In conclusion, gait parameters during CLG and CG are modified in the DT condition, resulting in a slower gait with shorter steps, regardless of age and sex. DTC is associated with physical fitness and cognitive function.

Motor competence is associated with the perceived difficulty of a task. This study hypothesized that children with higher motor competence perceive certain tasks as less challenging than their peers with lower motor competence. As a result, children with higher motor competence were expected to set more ambitious goals for themselves while learning a new task compared to children with lower motor competence. To investigate the relationship between motor competence and the difficulty of self-set goals during motor learning, we included 48 children aged between eight and ten years, stratified into terciles; our analysis focused on 32 children from the highest and lowest terciles. The experimental task required participants to throw a 100 g bean bag toward a target located 3 meters away. Children were instructed to set goals before each block of 10 trials during the learning phase. Pretest, retention, and transfer tests were administered without imposed goals. Motor competence was assessed using the Motor Competence Assessment, which integrates scores from the task used to evaluate motor learning and the percentage increase in each block to assess the difficulty of the self-set goals. The findings revealed no significant correlation between motor competence and the difficulty of self-set goals. Nevertheless, higher motor competence was linked to enhanced performance during the acquisition phase, retention and transfer tests. These results suggest that although motor competence is associated with improved motor learning, it does not influence the level of challenge of the goals that children set for themselves.

A holistic focus (HF) has been found to significantly improve performance over an internal focus (IF), in a similar way to an external focus (EF). There is a need to understand the effectiveness of a HF by investigating kinematic and kinetic outcome measures. 19 college-aged adults performed 12 vertical jumps under four conditions in a counterbalanced design. The conditions were, IF, EF, HF, and control, or no focus condition. All participants performed the vertical jumps on a force plate with 16 reflective markers placed on the lower extremities. Separate repeated measures ANOVAs with Sidak post-hoc were used to analyze jump height, flight height, peak force, takeoff velocity, and knee and hip flexion. A significant main effect for jump height was observed ( < 0.001). HF and EF jumped significantly higher than IF ( < 0.001;  < 0.001). EF also jumped significantly higher than control (<.05). No significant main effects were observed for any kinematic or kinetic dependent variables. The results of this experiment support previous research by observing performance benefits of HF and EF over an IF. However, the benefits of HF and EF cannot be attributed to the kinetic or kinematic changes.

Performance of sport-related ballistic motor skills, like ball hitting in golf and baseball, requires wide movements to produce highly fast and spatially accurate movements. In this study, we assessed the effect of movement amplitude on directional accuracy in a ballistic hitting task. Participants performed the task of moving a manual handle over a flat surface to hit with high speed a moveable disc, aiming to propel it towards a frontal target. Five movement amplitudes were compared, ranging from 11.5 cm to 27.5 cm in steps of 4 cm. Kinematic analysis evaluated motions of the handle, disc, and arm joints. Results showed that greater movement amplitudes led to longer acceleration phases, with delayed peak velocities at the handle, shoulder and elbow, leading to higher contact and peak linear velocities of the handle, and higher angular velocities at the shoulder and elbow. Manipulation of movement amplitude led to no evidence for effects on either disc directional accuracy or variability. Results also revealed no evidence for differences in variability of contact velocity, peak velocity and time of peak velocity across movement amplitudes in the shoulder, elbow, and wrist. Our results indicated that greater movement amplitudes in hitting a spatial target lead to increased contact velocity while not affecting directional accuracy or movement variability.

Individuals post-stroke commonly demonstrate alterations in motor behavior with regard to both task performance and the motor strategies used in pursuit of task goals. We evaluated whether constraining postural sway (motor strategy) during practice would affect upper-limb precision aiming performance (task performance) and postural control adaptations. Adults with stroke stood on a force plate while immersed in a virtual scene displaying an anterior target. Participants aimed to position a virtual laser pointer (via handheld device) in the target. Participants then completed practice trials involving aiming at a lateral target. For this practice session, participants were randomized to either (a) a "constraint" group wherein they received physical constraint to limit postural sway, or (b) a "no-constraint" group. Task performance and postural control were assessed before and after practice, and transfer to another upper-limb task was evaluated. After practice, both groups improved paretic upper-limb performance. For the target task, the no-constraint group showed task-sensitive changes in postural control. The constraint group showed no changes in postural control. At transfer, the constraint group increased postural sway. Constraining postural sway after stroke should be carefully considered with the recognition that postural sway arises from exploratory movements involved in the discovery of adaptable motor solutions.

This research examined how changes in task constraints impacted the throwing patterns of children. The study involved 24 children, with an equal number of males and females, aged 5 and 6. The primary task constraints were the orientation of the target (horizontal or vertical hoops) and the size of the ball (diameters of 6 cm or 12 cm). We observed throwing patterns and analyzed kinematic changes in the preferred throws' components. Initially, some children transitioned from using two hands to using one hand, and from underhand to overarm throws, particularly when using the larger balls. However, the preferred pattern for most children was one-hand overarm throwing. The kinematic analysis revealed that the participants adapted their throwing technique based on the size of the ball and the orientation of the hoop. The most significant adjustments occurred in the forearm component in response to changes in the target orientation. Notably, when aiming for a vertical hoop, distinct modifications were observed, including elevating the humerus and pulling the hand backward. These findings support the dynamical systems theory, which explains how movement patterns vary during motor development. The study also discussed the potential benefits of using constraints for skill acquisition in physical education settings.

Bilateral coordination of the upper limbs (UL) is important for activities of daily living and physical activities. Motor coordination improves from childhood through adolescence. However, age-coordination trajectories for bilateral UL movements are not well-established, and it is unclear if bimanual coordination develops slower than unilateral coordination. In this study we examined age-related changes in UL coordination from childhood to late adolescence. Typically-developing children ( = 29, aged 7-17 years) performed unilateral and bilateral, antiphase cycling tasks with their ULs. Variations in cycling velocity and interlimb phase errors were computed as measures of coordination. Linear regression was used to examine age-coordination effects. Given the sensorimotor processing for bilateral movements and gradual development of the corpus callosum, we hypothesized different relationships between age and coordination for bilateral and unilateral movements. Results showed UL coordination was significantly related to age, where coordination was better in older compared to younger children ( < 0.001); however, there were similar significant effects for unilateral movements. Differences in unilateral and bilateral coordination were not significantly explained by biological sex, although power to detect sex differences was low. We conclude that bilateral and unilateral UL coordination are age-dependent; each improves at similar rates through childhood and adolescence.

The present study aims to develop and present a proof-of-concept for a stop signal task with effector-specificity and higher complexity. Sixteen participants performed a stop signal task developed for lower extremities using Fitlight System™. The effect of four different delays and two sessions on response time, stop signal reaction time and accuracy was assessed using two-way repeated-measures ANOVA. The reliability of outcomes was assessed using intraclass correlation coefficients. There was a significant main effect of delay on all outcomes and an interaction of delay and session on accuracy. The reliability of outcomes was substantial with dependency on delays. Our preliminary findings suggest the feasibility of stop signal principles within more complex movements and provide an example for the development of further tests in sports context.

The functional equivalence model suggests a common internal representation initiates both imagery and execution. This suggestion is supported by the mental chronometry effect, where there is a positive relation between task difficulty (as defined by the Index of Difficulty; ID) and imagined movement time. The present study extends this logic by examining whether imagery captures the spatial trajectory. Participants were initially tasked with the imagery and execution of a rapid aiming movement under different IDs. These initial attempts were adapted to configure auditory tones at early (25%) and late (75%) intervals for a separate set of imagery trials. If a tone had sounded, participants had to estimate post-trial where their imagined limb would have been located. The findings revealed increases in ID that coincided with increases in imagined and executed movement times. However, participant mean and standard deviation of estimated locations revealed limited differences between the early and late tones. Further inspection revealed some evidence for these estimated locations shifting further along in space following more rapid imagined movements. While equivalence is clearly evident within the temporal domain, there is comparatively little to suggest that this logic extends to the resolution required for simulating the spatial characteristics of movement.

Cross-education (CE) is a phenomenon whereby motor training of one limb leads to improved performance in the opposite untrained limb. External pacing of a motor task can enhance CE; however, the influence of different pacing methods is poorly understood. This study explored how motor training with auditory (AP) and visual pacing (VP) impacts CE with a visuomotor force target task. Sixty-one participants performed a unimanual motor task. Participants were randomized into a visual ( = 31) or auditory ( = 30) pacing stimuli condition. The primary outcome was cumulative error scores for each hand, before and after visuomotor training. Pacing type did not yield different magnitudes of CE. However, after adjusting for baseline differences, a significant hand (trained vs. untrained) × practice side (dominant or non-dominant) interaction ( = .013, = .106) and a group main effect ( = .036, = .165) were observed. Visual pacing resulted in greater improvements in task performance compared to auditory pacing regardless of hand or practice side, while training the dominant limb resulting in a greater interlimb asymmetry regardless of pacing stimulus. These findings have implications for applying pacing strategies during rehabilitation from unilateral injury or neurological impairment.

Structural learning is characterized by facilitated adaptation following training on a set of sensory perturbations all belonging to the same structure (e.g., 'visuomotor rotations'). This generalization of learning is a core feature of the motor system and is often studied in the context of interlimb transfer. However, such transfer has only been demonstrated when participants learn to counter a specific perturbation in the sensory feedback of their movements; we determined whether structural learning in one limb generalized to the contralateral limb. We trained 13 participants to counter random visual feedback rotations between +/-90 degrees with the right hand and subsequently tested the left hand on a fixed rotation. The structural training group showed faster adaptation in the left hand in both feedforward and feedback components of reaching compared to 13 participants who trained with veridical reaching, with lower initial reaching error, and straighter, faster, and smoother movements than in the control group. The transfer was ephemeral - benefits were confined to roughly the first 20 trials. The results demonstrate that the motor system can extract invariant properties of seemingly random environments in one limb, and that this information can be accessed by the contralateral limb.

Increased conscious movement monitoring and control can impair sports performance. Recent evidence indicates it might facilitate stopping motor actions. To further investigate, we asked novices to putt balls, but they needed to stop promptly while an auditory cue appeared during the downswing. They also completed the Movement Specific Reinvestment Scale, which measures movement self-consciousness (MS-C) and conscious motor processing, indicating the degree of inclination for conscious movement monitoring and control, respectively. Individuals with high MS-C displayed higher stopping rates but longer stopping time. Further exploration suggests that they were more likely to make slow downswings, allowing successful but late stops. We conclude that increased conscious movement monitoring may affect movement execution in such a way that it affords better stopping of ongoing motor actions.

The aim of the study was to compare the effects of implicit learning using dual task-paradigm, with explicit learning on learning a novel skill, and if the performance is maintained over a prolonged period of time. Twenty-six high school adolescents ( = 26, boys  = 15, girls  = 11, age: 16 ± 0.66 years) performed a four-week front-flip learning program, where participants underwent two hours front flip practice in total between the pre- and post-test session followed by two tests; three and six months after the post-test, in which the front-flip was not practiced. Performance was evaluated by two independent gymnastics judges. Both groups increased performance at the post test, with significantly higher scores in the explicit group compared with the implicit group. Probably benefiting from error correction to select positive action outcomes and avoid negative ones consciously. However, the explicit group was also the only group that significantly decreased performance again at first retention test, suggesting that their reliance on the retrieval of declarative knowledge from working memory was subject to decay. While it seems that performance learned implicit learning may deteriorate more slowly, but also continuously throughout six months suggesting that the directly accumulated procedural knowledge may need for proper reinforcement and practice.

The benefits of less repetitive practice schedules on motor learning are usually described in terms of greater demand for memory processes. The present study aimed to investigate the interactions between working memory and practice schedule and their effects on motor learning. Forty female participants had their WMC evaluated by the N-back test and were randomly allocated to either the variable random (VP) or the constant practice (CP) groups. In the acquisition phase, participants practiced 120 trials of a sequential key-pressing task with two goals: learning the relative and the absolute timing. Delayed retention and transfer tests occurred 24 h after the acquisition phase. Participants performed 12 trials of the motor task. Results showed that in the CP, learners with a high level of WMC presented better motor performance in the transfer test than learners with a low level of WMC. In the RP, no difference between WMC levels was found. Learners with a high level of WMC in the CP presented the same motor performance as learners in the RP regardless of the WMC level in the transfer test. In conclusion, learners with a high WMC could compensate for the poor working memory stimulation of a more repetitive practice schedule. The high WMC did not seem to exert an additional benefit when learners were well stimulated by a less repetitive practice schedule.

This study focused on explicit instruction and evaluated the differences in task performance between participants who were instructed to employ the change and those who were not. Ninety-three healthy young adults were assigned to the accurate information group (AG;  = 31), misinformation group (MG;  = 31), and non-information group (NG;  = 31). All participants manipulated a mouse to track a moving target on a screen with a cursor. The cursor was rotated to 60° in the clockwise direction from the actual mouse position during the 1st to 5th blocks (i.e., motor adaptation task). Subsequently, in the 6th block (i.e., transfer task), we gradually changed the angle of rotation from 60° to 80° to prevent from noticing the change. Participants in the AG were instructed accurate experimental information. Participants in the MG were instructed that the angle of rotation was 60° during the 1st to 6th blocks. Participants in the NG were instructed to manipulate the cursor movement only. The results indicated that an average error distance in the AG was significantly lower than that in the NG in the 6th block. This study suggested that explicit instruction may impair the transfer of motor adaptation in this setting.

The present study investigated the effect of visual offset (visuo-proprioceptive mismatch) in joint repositioning task in a three-dimensional virtual reality (VR) environment when participants were instructed to ignore vision. Twenty-five physically healthy young individuals performed shoulder joint position sense test. Repositioning accuracy was tested under two visual conditions, accurate and offset visions, and two instructions, no guidance or ignore vision. In accurate vision trials, the virtual hand of the tested limb seen in VR was congruent with where the participant placed their hand. In the offset vision condition, the virtual hand was seen 8° above or below their actual hand in the vertical plane. Repositioning error (i.e. constant error) in offset vision trials was lower when the participants were instructed to ignore vision compared to when no instruction about the visual offset was given ( < 0.001). However, constant error in offset vision trials was larger than accurate vision trials when the participants tried to ignore vision in both visual conditions ( < 0.001). Our results suggest that humans may be able to down-weight vision to some extent by conscious effort, while the influence of vision is difficult to eliminate when vision is present.

We tested if the movement slowness of individuals with Parkinson's disease is related to their decreased ability to generate adequate net torques and linearly coordinate them between joints. This cross-sectional study included ten individuals with Parkinson's disease and ten healthy individuals. They performed planar movements with a reversal over three target distances. We calculated joint kinematics of the elbow and shoulder using spatial orientation. The muscle, interaction, and net torques were integrated into the acceleration/deceleration phases of the fingertip speed. We calculated the linear correlations of those torques between joints. Both groups modulated the elbow and shoulder net torques with target distances. They linearly coupled the production of torques. Both groups did not modulate the interaction torques. The movement slowness in Parkinson's disease was related to the difficulty in generating the appropriate muscle and net torques in the task. The interaction torques do not seem to play any role in movement control.

The ability to hold objects relies on neural processes underlying grip force control during grasping. Brain activity lateralized to contralateral hemisphere averaged over trials is associated with grip force applied on an object. However, the involvement of neural variability within-trial during grip force control remains unclear. We examined dependence of neural variability over frontal, central, and parietal regions of interest (ROI) on grip force magnitude using noninvasive electroencephalography (EEG). We utilized our existing EEG dataset comprised of healthy young adults performing an isometric force control task, cued to exert 5, 10, or 15% of their maximum voluntary contraction (MVC) across trials and received visual feedback of their grip force. We quantified variability in EEG signal via sample entropy (sequence-dependent) and standard deviation (sequence-independent measure) over ROI. We found lateralized modulation in EEG sample entropy with force magnitude over central electrodes but not over frontal or parietal electrodes. However, modulation was not observed for standard deviation in the EEG activity. These findings highlight lateralized and spatially constrained modulation in sequence-dependent, but not sequence-independent component of EEG variability. We contextualize these findings in applications requiring finer precision (e.g., prosthesis), and propose directions for future studies investigating role of neural entropy in behavior.

Motor behaviour using upper-extremity prostheses of different levels is greatly variable, leading to challenges interpreting ideal rehabilitation strategies. Elucidating the underlying neural control mechanisms driving variability benefits our understanding of adaptation after limb loss. In this follow-up study, non-amputated participants completed simple and complex reach-to-grasp motor tasks using a body-powered transradial or partial-hand prosthesis simulator. We hypothesised that under complex task constraints, individuals employing variable grasp postures will show greater sensorimotor beta activation compared to individuals relying on uniform grasping, and activation will occur later in variable compared to uniform graspers. In the simple task, partial-hand variable and transradial users showed increased neural activation from the early to late phase of the reach, predominantly in the hemisphere ipsilateral to device use. In the complex task, only partial-hand variable graspers showed a significant increase in neural activation of the sensorimotor cortex from the early to the late phase of the reach. These results suggest that grasp variability may be a crucial component in the mechanism of neural adaptation to prosthesis use, and may be mediated by device level and task complexity, with implications for rehabilitation after amputation.

The purpose of this study was to clarify the effects of the standing center of gravity sway by providing visual stimulus information as if the subjects were walking in virtual reality (VR) and by monitoring conditions with different corridor widths. We included 25 healthy young individuals in our study. The center of gravity sway was measured during open- and closed-eye static standing using images of walking in corridors of different widths (780 and 1600 mm) presented on a VR and personal computer monitor (Monitor). The parameters measured for the center of gravity sway were swing path length (SPL), height of excursion (HoE), and width of excursion (WoE). The results showed that the SPL and HoE values were significantly greater in the VR group than those in the Monitor group. The greater center of gravity sway in the VR compared with the Monitor group can be attributed to the ability of the head-mounted VR display to cover the entire field of vision and its head-tracking function. There was no change in the center of gravity sway with respect to the corridor width, which may be because the width of the corridor alone did not provide sufficient visual stimulation to affect physical function. This research could lead to further studies which could impact the motivation of patients for rehabilitation therapies.

Reciprocal inhibition and coactivation are strategies of the central nervous system used to perform various daily tasks. In automatic postural responses (APR), coactivation is widely investigated in the ankle joint muscles, however reciprocal inhibition, although clear in manipulative motor actions, has not been investigated in the context of APRs. The aim was to identify whether reciprocal inhibition can be observed as a strategy in the recruitment of gastrocnemius Medialis (GM), Soleus (So) and Tibialis Anterior (TA) muscles in low- and high-velocity forward and backward perturbations. We applied two balance perturbations with a low and a high velocity of displacement of the movable platform in forward and backward conditions and we evaluated the magnitude and latency time of TA, GM and So activation latency, measured by electromyography (EMG). In forward perturbations, coactivation of the three muscles was observed, with greater activation amplitude of the GM and lesser amplitude of the So and TA muscles. For backward, the pattern of response observed was activation of the TA muscle, a decrease in the EMG signal, which characterizes reciprocal inhibition of the GM muscle and maintenance of the basal state of the So muscle. This result indicates that backward perturbations are more challenging.

The Post-Movement Beta Rebound (PMBR) is the increase in beta-band power after voluntary movement ends, but its specific role in cognitive processing is unclear. Current theory links PMBR with updates to internal models, mental frameworks that help anticipate and react to sensory feedback. However, research has not explored how reactivating a preexisting action plan, another source for internal model updates, might affect PMBR intensity. To address this gap, we recruited 20 participants (mean age 18.55 ± 0.51; 12 females) for an experiment involving isolated (single-step) or sequential (two-step) motor tasks based on predetermined cues. We compared PMBR after single-step movements with PMBR after the first movement in two-step tasks to assess the influence of a subsequent action on the PMBR power associated with the first action. The results show a significant increase in PMBR magnitude after the first movement in sequential tasks compared to the second action and the isolated movements. Notably, this increase is more pronounced for right-hand movements, suggesting lateralized brain activity in the left hemisphere. These findings indicate that PMBR is influenced not only by external stimuli but also by internal cognitive processes such as working memory. This insight enhances our understanding of PMBR's role in motor control, emphasizing the integration of both external and internal information.

This study examined whether target pursuit tracking by a performer-controlled computer cursor around a square diamond-shaped circuit, using isometric pinch grip force production, would show a significant difference in performance metrics dependent on the clockwise sense of the target movement along the trajectory path. The target template incorporated path segments requiring all four possible combinations of directional force modulation patterns (increasing and decreasing isometric pinch forces of the thumb and index finger). Overall, it was found that cursor positional accuracy was greater during counterclockwise pursuit, that steadiness was greater during clockwise pursuit, and that the cursor bearing angle with respect to target movement was biased toward cursor positioning being within the interior of the trajectory circuit regardless of clockwise sense.

The benefits of allowing learners to control when to receive knowledge of results (KR) compared to a yoked group has been recently challenged and postulated to be mild at best. A potential explanation for such dissident findings is that individuals differentially utilize the autonomy provided by the self-controlled condition, which, in its turn, affects the outcomes. Therefore, the present study investigated the effects of self-controlled KR on motor learning focusing on the frequency of KR requests when performing an anticipatory timing task. Self-controlled groups were created based on participants' KR frequency of request (High, Medium, and Low referring to fifth, third, and first quintile) and, then, Yoked groups were created self-control condition pairing the KR request of the Self-controlled groups. We also measured self-efficacy and processing time as means to verify potential correlates. The results supported the expected interaction. While no difference between self-controlled and yoked groups were found for low frequencies of KR, a moderate amount of KR request was related to better results for the self-controlled group. Nonetheless, the opposite trend was observed for high frequencies of KR; the yoked group was superior to the self-controlled group. The results of this study allow us to conclude that the choices made, and not just the possibility of choosing, seem to define the benefits of KR self-control in motor learning.

Lower back disorders (LBDs) affect a large proportion of the population, and treatment for LBDs have been shifting toward individualized, patient-centered approaches. LBDs are typically associated with poor proprioception. Therefore, there has been a recent uptake in the utilization of wearable sensors that can administer biofeedback in various industrial, clinical, and performance-based settings to improve lumbar proprioception. The aim of this study was to investigate whether wearable sensor-derived acute auditory biofeedback can be used to improve measures of gross lumbar proprioception. To assess this, healthy participants completed an active target repositioning protocol, followed by a training period where lumbar-spine posture referenced auditory feedback was provided for select targets. Target re-matching abilities were captured before and after acute auditory biofeedback training to extract measures related to accuracy and precision across spine flexion targets (i.e., 20%, 40%, 60%, 80% maximum). Results suggest a heterogenous response to proprioceptive training whereby certain individuals and spine flexion targets experienced positive effects (i.e., improved accuracy and precision). Specifically, results suggest that mid-range flexion targets (i.e., 40-60% maximum flexion) benefited most from the acute auditory feedback training. Further, individuals with poorer repositioning abilities in the pre-training assessment showed the greatest improvements from the auditory feedback training.

The purpose of this study was to investigate the difference in oculomotor functioning between Olympic-level contact and non-contact sports participants. In total, 67 male and female Olympic-level contact ( = 27) and non-contact ( = 40) athletes completed oculomotor tasks, including Horizontal Saccade (HS), Circular Smooth Pursuit (CSP), Horizontal Smooth Pursuit (HSP), and Vertical Smooth Pursuit (VSP) using a remote eye tracker. No significant differences for sex or age occurred. Each variable indicated higher scores for contact compared to non-contact athletes ( < .05) except for VSP Pathway differences and CSP Synchronization. A logistic regression was performed to determine the degree that HS measures, CSP synchronization, and VSP pathway predicted sport type. The model was significant, (6) = 37.08, < .001, explaining 57.4% of the variance and correctly classified 88.1% of cases. The sensitivity was 87.5% and specificity was 88.9%. CSP synchronization did not increase the likelihood of participating in a contact sport. This was the first study to identify oculomotor differences between Olympic athletes of contact and non-contact sports, which adds to the growing evidence that oculomotor functioning may be a reliable, quick, real-time tool to help detect mTBI in sport.