This study aimed to evaluate the application of the PoST framework in a team sport context and compare two data-driven classification methods to objectively assess the skill training outcomes. Training drills were assessed for information complexity and game-representativeness using variables describing the training environment and athlete performance. Coach classifications of drills were analysed using repeated-measures MANOVAs, while k-means and Gaussian Mixture Model (GMM) clustering objectively grouped drills based on information complexity, and compared with PoST stages. Coach classifications varied, with training intentions not always clearly distinguished, and similar game-representativeness observed across classifications, despite PoST emphasising this as a key differentiator. Both clustering methods identified three distinct training types, aligning with PoST's ‘Complex Training’, ‘Team-based Training’ and ‘Performance Training’ stages. However, the probabilistic overlap of the GMM better captured drills transitioning between stages. Neither method identified drills reflecting PoST's Coordination stage, suggesting misalignment between coach intent and the framework's definition. Coaches should consider both training complexity and representativeness to better align drills with game demands and desired outcomes. A modified framework designed for team-level skill development may support this, while objective classification methods may be used to enhance training design and evaluation.
Post-stroke walking impairment reflects both motor and higher-order cognitive deficits. We examined whether executive function mediates the association between walking-related motor imagery accuracy and actual walking performance and kinematics in patients with subacute hemiparetic stroke. Thirty inpatients underwent mental chronometry, involving timed imagined and actual maximum 10-m walks, and the discrepancy between the two was expressed as the Index of Walking Performance (IWP), with values near zero indicating high accuracy. Participants were categorized into overestimation and underestimation groups. Executive function was assessed with the Trail Making Test Part B (TMT-B). Walking outcomes included maximum 10-m walking time, the Timed Up and Go test (TUGT), and paretic peak knee flexion during stance and swing phases. Mediation analyses with TMT-B as the mediator were conducted both without covariates and after adjustment for age and position sense. Higher IWP values were associated with longer TMT-B times, slower maximum 10-m walking and TUGT, greater paretic stance-phase, and smaller swing-phase knee flexion. The overestimation group showed slower maximum 10-m walking and smaller swing-phase knee flexion than the underestimation group. Unadjusted models showed full mediation for the TUGT and stance-phase knee flexion, partial mediation for swing-phase knee flexion, and no mediation for the maximum 10-m walking time. After adjustment, these indirect effects were attenuated, and their confidence intervals included zero, whereas associations of IWP and TMT-B with the walking outcomes remained significant. Executive function may therefore contribute to the association between walking motor imagery accuracy and actual walking performance, although its mediating role remains preliminary.
OPTIMAL (Optimizing Performance Through Intrinsic Motivation and Attention for Learning) theory proposes that enhanced expectancies, autonomy support, and an external focus of attention facilitate motor learning. This study examined whether a putting program incorporating these factors would improve performance under low-stress and high-stress conditions. Thirty-two novice college students aged 18-25 years (13 women and 19 men; mean age = 24.09 ± 1.52 years) were randomly assigned to an OPTIMAL or control group. Participants completed a pretest, three 20-putt practice sessions, and a retention test 1 day later. The pretest and retention test each included 20 putts under each stress condition. During practice, the OPTIMAL group received positive social-comparative feedback, selected the sequence of colored golf balls, and was instructed to adopt an external focus, whereas the control group completed matched practice without these manipulations. A significant group × time interaction was found for putting performance, F(1,30) = 18.982, p < .001, η2p = 0.388. Collapsing across stress conditions, the OPTIMAL group improved from the pretest to the retention test (p < .001) and outperformed the control group at the retention test (p = .007). Putting scores were lower under the high-stress condition than under the low-stress condition, F(1, 30) = 14.468, p < .001, η2p = 0.325. No group-related effects were found for anxiety. The integrated OPTIMAL program improved golf putting learning across stress conditions, but no evidence of a stress-specific protective effect or improved anxiety regulation was found.
Attentional-focus research commonly treats external focus (EF) as a single strategy, although instructions assigned this label may differ in spatial referents and informational content. This study examined whether reliance on author-reported labels was associated with differences in evidence inclusion and meta-analytic inference for jump performance. Five databases were searched, and four prespecified random-effects network meta-analysis (NMA) models were fitted. Model 1 operationally reclassified all 49 eligible datasets at the instruction level. Model 2 retained 41 datasets reported using the generic EF label, Model 3 retained 7 datasets explicitly labelled as proximal external focus (PEF) or distal external focus (DEF), and Model 4 retained 48 datasets while preserving all explicit author-reported categories. Operational review reassigned 42 instructions. In Model 1, PEF, DEF, and holistic focus (HF) improved jump performance relative to control, with standardized mean differences (SMDs) of 0.189, 0.264, and 0.331, respectively. Generic EF estimates in Models 2 and 4 were similar (SMDs = 0.209 and 0.216) and fell between the PEF and DEF estimates from Model 1. Model 3 produced larger but less precise PEF and DEF estimates. Most 95% prediction intervals included the null. Reliance solely on author-reported attentional-focus labels may be associated with differences in evidence inclusion, network structure, heterogeneity, consistency, precision, and resulting conclusions. Future evidence syntheses and systematic reviews should therefore apply prespecified and reproducible instruction-level classification criteria. Primary studies should also report attentional focus more precisely, including the complete wording of each instruction, its intended referent, and relevant information regarding the distance or spatial orientation of that referent.
Bimanual coordination depends on the ability to flexibly regulate interlimb coupling while maintaining independent control of each limb. Aging and Parkinson's disease (PD) may disrupt this balance by altering sensorimotor regulation and shared neural input between limbs. This study examined force control, coordination dynamics, and physiological coupling during unimanual and bimanual isometric force tasks in healthy young adults (HYA), healthy older adults (HOA), and individuals with Parkinson's disease (PD). Participants completed 30 s unimanual and bimanual force tasks with target forces set at 20% maximal voluntary contraction (MVC). During unimanual tasks, participants produced the target force with one limb while the uninstructed limb rested on a force transducer. During bimanual tasks, both limbs produced the target force. Beginning 15 s after trial onset, visual feedback for the instructed limb in the unimanual tasks or one designated limb in the bimanual tasks was removed for 10 s. Behavioral measures included constant error (CE), coefficient of variation (CV), and interlimb force-force cross-correlation, while physiological coupling was quantified using EMG-EMG coherence between homologous first dorsal interosseous (FDI) muscles. PD participants demonstrated greater force variability, greater unintended force production in uninstructed limbs, and stronger interlimb force-force coupling relative to HYA and HOA participants, with group differences most pronounced during bimanual conditions. Whereas HYA and HOA participants generally increased force variability following removal of visual feedback, PD participants demonstrated reduced variability when feedback was removed. EMG-EMG coherence was elevated in PD across frequency bands and task conditions, while HYA and HOA participants demonstrated comparatively lower and more feedback dependent coherence patterns. Behavioral and physiological measures provided converging evidence of stronger and less adaptable interlimb coupling in PD. These findings indicate altered and less adaptable regulation of sustained force output in PD and are consistent with greater shared neural input to homologous muscles and reduced flexibility in the independent regulation of force across the limbs.
