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Sensory reweighting of postural control was compared in participants with and without neck pain. Center of pressure variables of 60 volunteers, the same in each group, were calculated under four standing conditions: (a) eyes open, neutral head posture; (b) foam interface, eyes open; (c) cervical extension, eyes open; and (d) cervical extension, eyes closed. All center of pressure variables except anterior posterior range/velocity increased significantly in Condition 2 compared with Conditions 1 and 3 (p < .001) and in Condition 4 compared with Conditions 1 and 3. The mediolateral range/velocity and path length in both groups, anterior posterior range in patients, and center of pressure area in the control group were significantly different between Conditions 2 and 4 (p < .001). No overweighting was observed on the vestibular or visual afferents in patients. Compensatory strategies seem to lie within the proprioceptive system.

This study aimed to verify the behavior of physiological, perceptual, and performance responses during a high-intensity exercise in judo athletes and to identify if this protocol is able to discriminate athletes from different levels (national vs. state). Forty-five male judo athletes participated and were divided into two groups: state (age 24.2 ± 3.7 years) and national (22.1 ± 3.3 years). Judo athletes performed a judo-specific protocol contained high-intensity intermittent exercise consisted of 12 sets of 20 s in all-out intensity. During the protocol, the repetitions and heart rate were assessed over the sets, and at the end of the protocol, the rate of perceived exertion was measured. The results showed that the national group presented higher repetitions (29 ± 4 repetitions) during the high-intensity intermittent exercise compared with state (22 ± 2 repetitions). However, the national group showed a progressive decrease of repetitions up to the middle of the protocol, which coincided with higher values of heart rate compared with state (first and second sets). There was a decrease of repetitions from the first set (p < .001) and similar values of heart rate from the third set in the state. In conclusion, the performance (in repetitions) during the high-intensity intermittent exercise was able to discriminate athletes from different competitive levels. National athletes presented better performance, but worse pacing strategy compared with state.

This review of movement stability, optimality, and agility is based on the theory of motor control with changes in spatial referent coordinates for the effectors, the principle of abundance, and the uncontrolled manifold hypothesis. A new optimality principle is suggested based on the concept of optimal sharing corresponding to a vector in the space of elemental variables locally orthogonal to the uncontrolled manifold. Motion along this direction is associated with minimal components along the relatively unstable directions within the uncontrolled manifold leading to a minimal motor equivalent motion. For well-practiced actions, this task-specific criterion is followed in spaces of referent coordinates. Consequences of the suggested framework include trade-offs among stability, optimality, and agility, unintentional changes in performance, hand dominance, finger specialization, individual traits in performance, and movement disorders in neurological patients.

This study aimed to analyze the effect of a variable practice training in the double wall right forehand by using wrist weights. Thirty-four experienced padel players participated in this study. Players were randomly distributed in two groups (control group [CG] and training group [TG]). The TG performed 1 month of variable training, induced by weighted wrist bands, twice a week, with the same number of sessions and volume of training as the CG. TG obtained significant difference in posttest measurements (effect size = 0.437) in terms of the number of successful shots compared to CG (effect size = 0.027). These findings showed a significant effect of the TG with respect to the CG. Results reinforce the role of variability in the exploration and reinforcement of motor learning.

This systematic review aimed to synthesize the current evidence on the feasibility of volitional reaction time (RT) tests to evaluate the information processing abilities of athletes. Four databases were searched, and, finally, 38 studies exploring the reliability, validity, or sensitivity of RT tests were included. Seven studies explored the reliability, which ranged from poor to excellent, while only three studies explored the validity of RT tests. The most important downside of the majority of the implemented RT tests is their nonspecific nature (i.e., stimulus and response did not resemble the sports actions). Sports scientists should focus on developing RT tests that are specific for each sport and refine the testing procedures to obtain accurate, reproducible, and sensitive measurements of RT.

This study aimed to explore the effect of sex and force level on grip force reproduction in healthy adults by conducting a force reproduction task. Participants (n = 28) were instructed to replicate a range of reference grip force levels (10–130 N in 10 N increments). We found that women (absolute error: 16.2 ± 8.7 N) replicated these force levels more accurately than men (absolute error: 23.1 ± 9.5 N) at higher force levels (90–130 N). Furthermore, the force reproductions were most accurate at the 30–50 N range for men and the 50–60 N range for women. These results may offer significant insights into the higher rates of musculoskeletal disorders among women, enabling researchers and clinicians to design novel interventions and tools that can improve grip force perception and reduce hand injury rates in both men and women.

The purpose of this study is to examine changes in the kinetic parameters of the fingers caused by differences in ball velocity during overarm throwing. Six baseball players participated in the study, and the kinetics of the wrist and metacarpophalangeal (MP) joint were calculated using an inverse dynamics method. The results of Tukey’s multiple comparison tests showed that the torque and work of the wrist increased with increasing ball velocity (p < .05), indicating that wrist torque and work contributed to the adjustment of ball velocity. Peak MP joint torque also increased with ball velocity (p < .05), although the work of the MP joint remained relatively constant. We conclude that MP joint torque and work contribute to the achievement of stable ball release rather than adjusting ball velocity.

This study aimed to examine the feasibility of using time-to-contact measures during the perturbation protocol in people with diabetes mellitus. Three-dimension motion capture and force data were collected during 0.5-s perturbations in four directions (forward, backward, right, and left) and at two accelerations (20 and 40 cm/s²) to compute the time-to-contact. Time-to-contact analysis was divided into three phases: perturbation, initial recovery, and final recovery. The statistical analysis showed the main effects of Direction and Phase (p < .01) as well as a Direction by Phase interaction (p < .01). Backward perturbation with lower acceleration and backward/forward perturbation with higher acceleration had deleterious effects on postural stability in people with diabetes mellitus.

Age-, height- and weight-matched children were recruited to the experimental group (EG; n = 31) and control group (n = 32). Following a 16-week soccer training program, balance ability and dominant-side lateral knee and ankle kinesthesia changes were tested. Regarding balance ability, the Sway Index, when children stood on a firm or foam surface with their eyes closed in the static balance test, and the dynamic balance test time were 13.5%, 11.6%, and 14.3% lower in the EG than in the control group, respectively. The scores in the left and right directions were 23.7% and 24.2% higher in the EG, respectively. Regarding kinesthesia, the angle of knee extension and ankle metatarsal flexion and dorsiflexion were 13.4%, 20.0%, and 16.8% lower in the EG than in the control group. These results indicate children in the EG had a better performance. After soccer exercise, children aged 5–6 years displayed improved balance in the left and right directions and improved knee extension, ankle plantarflexion, and dorsiflexion kinesthesia.