Journal of Motor Behavior最新文献

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.

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.

Background: By stimulating proprioceptive receptors, muscle vibration helps understand the crucial role of proprioception in gait control. From the literature, variability in responses during the stance phase across studies may be due to protocol differences, such as lighting conditions that affect visual information. This study aimed to investigate the interaction between vision and proprioceptive information from ankle and neck muscles over the gait cycle during treadmill walking.

Methods: Twenty-five healthy participants (aged 30 ± 5 years) walked on an instrumented treadmill under three visual conditions (eyes open, dim light and eyes closed) and three vibration conditions (no vibration, neck muscles and ankle plantar flexor muscles) in a randomised order. The centre of pressure (COP), pelvis and head positions were measured and analysed across three gait cycle phases (heel contact, midstance and toe-off). A mixed-effects model on ranks was used for analysis, with post-hoc Tukey corrections for significant interactions.

Results: No significant interaction was found between vibration conditions, different visual conditions, and the gait cycle on the COP, pelvis and head positions (p > 0.42). Neck muscle vibration caused a forward shift in the COP at heel contact (p = 0.0006) and midstance (p < 0.0001) and in pelvis and head positions throughout the gait cycle (p < 0.0001). Ankle muscle vibration had no significant effects (p > 0.4). Eye closure led to more pronounced gait reactions compared to eyes open or dim light at heel contact and toe-off (p = 0.0001).

Discussion: This study investigated the influence of vision and proprioception during walking by manipulating visual information (eyes open, dim light and eyes closed) and proprioceptive information (neck and ankle vibration). Under these specific experimental conditions, no clear interactive effects between vision and proprioception were observed. Instead, their contributions appeared at distinct moments of the stance phase: both modalities influenced gait control at heel contact, neck proprioception effects were more pronounced at midstance, and vision contributed more strongly at toe-off. These findings enhance understanding of sensory contributions during walking and support further exploration of vibration application protocols.

Theories of human motor learning commonly assume that movement plans are adjusted in response to the sensory feedback received about their success or failure. The degree to which movement errors drive changes in feedforward motor plans is further assumed to scale inversely with sensory uncertainty. However, support for these assumptions comes primarily from experiments that limit feedback corrections during an ongoing movement. In contrast, we have recently shown that when this restriction is relaxed, a different pattern of behavior emerges. Participants gradually adjust their reaching movements in response to a perturbation from trial-to-trial, following a consistent and incremental envelope of error reduction. Riding on top of this gradual learning envelope, participants also exhibit large and abrupt changes in their initial reach direction that are strongly correlated with the uncertainty level of the sensory feedback experienced on the previous trial, but are insensitive to the size and direction of the movement error made on that trial. A class of models in which sensory uncertainty influences an aiming process best accounted for this pattern. Here, we examine the possibility that uncertainty acts as a contextual cue to shunt motor processes to one of many context-specific internal models.

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.

Deficits in internal modeling have been suggested as a key factor contributing to the motor control and coordination challenges experienced by children with DCD. Recently, virtual reality (VR) technology has emerged as a promising tool for enhancing the acquisition and learning of motor skills. Therefore, the primary aim of this study was to investigate the effects of VR-based interventions on internal modeling and object control skills in children with DCD. The present study employed a quasi-experimental design, incorporating a pretest, post-test, and two-month follow-up. The sample consisted of 40 female students aged 7 to 10 years, selected based on DSM-5 criteria and randomly assigned to either a VR training program or a control group. Predictive internal modeling was assessed using continuous relative phase (CRP) through a visuomotor adaptation task, while object control skills were evaluated using the TGMD-2 test. The experimental group underwent an 8-week VR-based training program comprising 16, 30-minute sessions using task-oriented Xbox Kinect 360 games. The control group received no intervention. Results indicated that VR training significantly improved the acquisition of CRP (p = 0.037), with the experimental group demonstrating superior transfer of these skills to object control tasks compared to controls (p < 0.001). The observed reduction in CRP suggests that VR training facilitated the development of internal models in children with DCD. Furthermore, enhancements in object control skills evidenced the capacity of these children to apply and generalize acquired predictive internal models. However, despite these advancements, participants continued to exhibit compensatory strategies characterized by variability and inaccuracy, indicating persistent challenges in internal model updating.

Visual-motor illusion (VMI) is a kinesthetic illusion produced by viewing an image showing joint motion. VMI with enhanced joint movement intensity (power-VMI; P-VMI) is expected to activate a wide range of motor association brain regions, and when combined with electrical stimulation that activates the motor sensory cortex, further activation of brain activity can be expected. This study aimed to verify the effectiveness of VMI using functional near-infrared spectroscopy to confirm brain activity during combined P-VMI and electrical stimulation. Brain activity was measured in 15 healthy adults during three tasks performed on the left ankle joint: P-VMI with electrical stimulation, P-VMI alone, and electrical stimulation alone. The tasks were performed randomly on a single participant. Brain activity was measured during each task using a protocol comprising 15 s of rest, 30 s of task performance, and 30 s of follow-up. Regions of interest included motor-related areas. The results showed that P-VMI alone activated the right superior parietal lobule and left supramarginal gyrus more than P-VMI combined with electrical stimulation. These findings suggest that P-VMI and sensory-threshold electrical stimulation do not necessarily complement each other in enhancing brain activity, as P-VMI alone shows greater activation in specific motor-related brain regions.

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 (p < 0.001), cadence (p < 0.01), and step length (p < 0.001). In addition, double support time (p < 0.05) and cadence coefficient of variance (boys= p < 0.01; girls= p < 0.05) increased in the DT condition. In the CG, both sexes (p < 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 (p < 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.

Fundamental motor skills (FMS) play a critical role in the physical activity engagement and health of children. In this study we described inter- and intra-skill changes in preschoolers FMS mastery across a mastery motivational climate (MMC) intervention. Fifty-six children (27 boys, 29 girls, Mage = 4.5) participated in a twice weekly, 30-minute MMC intervention for 29 sessions. Pre-post FMS were measured using the test of gross motor development-3. Girls showed larger FMS mastery changes in their locomotor (LM) skills than boys. The largest changes in LM skill mastery occurred in run, slide, and jump. For ball skill mastery, boys showed greater improvements in throwing compared to two-hand strike, dribble, and kick for girls. Our findings may inform the design and instructional strategies of future interventions.

Adopting a postural configuration may be regarded as preparation for the performance of an upcoming movement. However, it is unclear how different postural configurations affect motor performance. The aim of the current study was to examine how body posture - sitting versus standing - influences fast and accurate planar point-to-point hand movements. Twenty-three healthy adults performed a "Go/No-go" paradigm while doing repetitive point-to-point movements. Arousal levels, which may change due to the change in posture, were independently manipulated by using a sham threat of electrical stimulation. Upper limb kinematics, center of pressure displacement, and galvanic skin responses were recorded in four test conditions: sitting and standing with and without arousal manipulation. Descriptive performance measures were computed and analyzed using multiple analyses of variance. A difference in arousal level was observed in the two conditions with the arousal manipulation, but no difference in arousal level was found between sitting and standing. Center of pressure displacement onset was found to be earlier in the two standing conditions compared to those in sitting. No difference was found in upper limb performance between the two postures, nor due to the arousal manipulation. We concluded that under the tested conditions, body posture does not appear to affect upper limb performance.