Journal of Motor Behavior最新文献

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.

This study investigates the neurophysiological and biomechanical factors contributing to successful basketball throw performance in novice athletes, utilizing electroencephalography (EEG) and motion capture (MoCap) to analyze joint angles, ground reaction forces (GRFs), and brain activity. Sixteen participants performed basketball throws while EEG and MoCap systems recorded data on movement mechanics and neural activity. Biomechanical findings revealed that successful trials were characterized by refined movements, reduced wrist extension, increased elbow flexion, and more stable foot positioning compared to unsuccessful trials (all p > 0.05), contributing to greater shot accuracy. Reduced movement variability in successful trials further indicated improved motor consistency, reflective of skill development. EEG results showed higher beta and gamma power in the temporal lobe during successful compared to unsuccessful trials (p < 0.05), suggesting increased engagement in visuomotor integration and neural efficiency. Notably, our novice participants demonstrated limited neural efficiency in frontal regions (p > 0.05), potentially due to cognitive interference and self-monitoring. These findings highlight the importance of coordinated biomechanical execution and neural efficiency in optimizing basketball performance. The insights gained have practical implications for designing training interventions that improve motor performance, particularly for novice athletes.

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 (F = 10.12, p = 0.004, partial ƞ2 = 0.14), and limb preference main effect (F = 5.39, p = 0.03, partial ƞ2 = 0.19), without significant interactions (p > 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% (MDC₉₀) 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.

Prolonged movement time as a function of task difficulty (as defined by the Index of Difficulty [ID]) can be equally prevalent within executed and imagined movements ─ something referred to as the mental chronometry effect. This effect has been leveraged as support for functional equivalence, where an internal representation can be shared for execution and imagery. However, times tend to rise exponentially more for imagined, compared to executed, movements, which could be attributed to the time spent within a task. Fifteen participants attempted execution and imagery of a reciprocal aiming movement between two targets that assumed different levels of ID (4, 5, 6 bits). They did this either over 3 or 5 cycles of movement to generate short- and long-duration movements, respectively. Mean times and time-ID slope/gradient coefficients revealed that the time within imagery was generally no longer than execution. However, the rise in time as a function of ID tended to be even greater when undertaking 3 compared to 5 cycles within imagery, but not execution. Overall, these findings may counter the suggestion that time spent within imagery is positively related to duration. However, further research is perhaps warranted to help formulate broader recommendations for imagery across different durations.

This study investigated whether combining virtual reality (vr) with balance beam training enhances balance performance in young adults more effectively than vr alone, addressing the limited research on their combined effects. thirty-nine participants were randomly assigned to one of three groups: VR with balance beam training, VR alone, or a control group. Participants in the VR groups completed a 5-min rope walking VR game in four sessions per day, 3 days per week, for 4 weeks. Balance was assessed using the Neurocom Balance Master before and after the intervention. Both the combined VR and balance beam group and the VR alone group showed significant improvements compared to the control group, including reduced tandem walk end sway, increased movement velocity, improved maximum excursion in the limit of stability, and decreased sway velocity during single-leg stance with eyes opened. However, no significant differences were found between the combined group and the VR alone group. These findings suggest that both VR combined with balance beam training and VR alone can significantly improve balance in young adults. This indicates that either approach could be effectively used to enhance balance in this population.

Clinical trial registration number: The study was registered at www.thaiclinicaltrials.org (No. TCTR20201217005).

Numerous devices are being developed to assist visually impaired and blind individuals in performing everyday tasks such as reaching out to grasp objects. Considering that the size, weight, and cost of assistive devices significantly impact their acceptance, it would be useful to know how effective various types of guiding information can be. As an initial exploration of this issue, we conducted four studies in which participants with normal vision were visually guided toward targets. They were guided by information about the direction to the target, and either about the distance to the target or about the time required to reach the target. We compared participants' performance when provided with different amounts of each of these kinds of information. We found that restricting information about the distance from the target or the time it would take to reach the target to only a few possible values does not affect performance substantially. Restricting information about the direction to the target to only a few possible values appears to be more detrimental, but the disadvantage of having few possible directions can be mitigated by combining values in multiple directions. These findings can help optimize haptic presentations in assistive technology.

To determine how motor control patterns in wheelchair propulsion mediate attentional demands. Fourteen participants completed two single- and dual-task trials of Serial-7 Subtraction and four, 30-second motor tasks: Static Sitting, Short Leans, Maximal Leans, and Stationary Propulsion. Differences in cognitive and motor function were determined through paired samples t-tests and percent changes (dual-task costs [DTCs]) were calculated. Within-subjects, repeated-measures ANOVAs determined differences in DTCs across motor tasks. Cognitive function was maintained from the single- to dual-task trials across tasks (DTC ≤ 13%; p = 0.12-0.74). Motor function was uniquely maintained during Maximal Leans (DTC ≤ 0.5%; p = 0.12-0.93), which yielded significantly lower dual-task cognitive function than the others (p < 0.01). Seated balance may be the primary contributor to the attentional demands of wheelchair propulsion.

Persistent contact sport participation exposes athletes to repetitive head impacts, eliciting lingering motor performance alterations that could disrupt visual perception. We sought to compare head and trunk displacement, segmental coordination, and dynamic visual acuity between contact (ice hockey) and noncontact (baseball) athletes. Thirteen ice hockey and 11 baseball athletes walked at preferred and fast speeds during both a baseline and an imposed dynamic visual acuity (DVA) task. With increased visual task constraints and walking speeds, greater vertical head (preferred walking with visual task: 4.29 ± 0.48 vs 3.69 ± 0.71 cm, p = 0.030; fast baseline walking: 5.91 ± 0.59 vs 5.00 ± 0.97 cm, p = 0.019; fast walking with visual task: 5.72 ± 0.62 vs 4.86 ± 0.79 cm, p = 0.005) and trunk CoM displacement (fast baseline walking: 5.84 ± 0.61vs 5.00 ± 0.95 cm, p = 0.026; fast walking with visual task: 5.65 ± 0.63 vs 4.89 ± 0.78 cm, p = 0.014) were observed in contact athletes. In the transverse head-trunk coordination, contact athletes showed a decreased contribution of the head (9.85 ± 5.57 vs 19.36 ± 9.84%, p = 0.007) and increased trunk involvement (47.31 ± 21.43 vs 33.64 ± 10.79%, p = 0.030) compared to noncontact athletes, but this occurred only during fast walking with the DVA task. No DVA differences were observed (preferred speed: p = 0.650; fast speed: p = 0.820). While visual task performance was unaffected by contact sport status, the current results demonstrate changes in upper-body movement and how the head and trunk are coordinated in ice hockey athletes. Whether the observed upper-body movement and coordination changes due to repetitive head impact exposure result in decrements in visual perception and awareness in more challenging sporting environments remains unclear.

Real-time visual biofeedback (vBF) of body sway is known to enhance postural control by reducing center of pressure (COP) displacement. However, the mechanisms underlying its influence remain unclear, particularly regarding implicit processing. The objective of this study was to examine whether vBF is utilized implicitly by exposing 40 young adults to both real-time (accurate) and erroneous (delayed) COP feedback without explicitly explaining its purpose. Participants were simply instructed to stand as still as possible. After the experiment, 15 out of 40 participants spontaneously recognized the feedback's nature. Results indicated that both aware and unaware participants exhibited improved postural control under accurate vBF (i.e., reduced COP variability, smaller COP area, increased COP irregularity, and greater reliance on higher sway frequencies). In contrast, erroneous vBF induced minimal changes. While these findings highlight a possible implicit integration of the visual feedback, the results also underscore the need for future research to investigate this phenomenon with more refined methods, as classifying participants into aware and unaware groups presents certain challenges.

In the biomechanics of striking tasks, different types of visual feedback for the upper extremities influence motor learning and control in distinct ways. Quantitative feedback (QN), which provides precise numerical data, and qualitative feedback (QL), which offers descriptive or interpretive guidance, may facilitate different aspects of motor skill acquisition. Given that ballistic motor skills, such as the badminton underhand-clear stroke, require not only rapid and coordinated movement execution but also precise control of distal joints for accuracy, the underlying feedback processing mechanisms play a crucial role in optimizing motor control. Therefore, this study aims to determine the most effective type of visual feedback for enhancing motor learning in the badminton underhand-clear stroke by examining its impact on movement efficiency and accuracy. Participants (n = 36, all male; mean age 25.1 ± 1.2 years) were recruited into three groups: QN group, QL group, and the control group. Each participant completed a pretest, post-test, and retention-test of 20 trials each for the badminton underhand-clear stroke, along with three practice sessions consisting of 50 trials each. Performance accuracy and coordination patterns were significantly improved in the QN group compared to the QL and control groups in the retention test [performance accuracy (mean radial error) = QN-control: p < .01, QN-QL: p < .01; coordination pattern (discrete relative phase) = QN-control: p < .001, QN-QL: p < .01]. Additionally, the kinematics of the wrist joint were significantly improved in the QN group compared to the QL and control group in the retention test (maximum extension angle of wrist joint = QN-control: p < .001, QN-QL: p < .01). These findings suggest that quantitative feedback may be more effective than qualitative feedback in facilitating motor learning in a badminton striking task, particularly in terms of long-term retention of movement accuracy and coordination. By analyzing motor coordination patterns, this study provides insight into the role of different types of visual feedback in motor learning and offers practical implications for instructors aiming to optimize skill acquisition in striking tasks.