| The Stability–Agility Trade-off in Fast Paced Motor Skill |
| Paper ID : 1668-SPORTCONGRESS |
| Authors |
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Alireza Aminaee *1, Shahzad Tahmasebi Boroujeni2, Elahe Arab Ameri3, Mehdi Shahbazi4, علی شریف نژاد5 1Assistant Professor, Faculty of Sport Sciences and Health, University of Tehran, Tehran, Iran 2Department of Cognitive and Behavioral Sciences, Faculty of Sport Sciences and Health, University of Tehran, Tehran, Iran.Professor 3Department of Behavioral and Cognitive Science in Sports, Faculty of Sports Science and Health, University of Tehran, Tehran, Iran 4Department of Cognitive and Behavioral Sciences, Faculty of Sport Sciences and Health, University of Tehran, Tehran, Iran. 5Department of Sport Biomechanics and Technology, Sport Science Research Institute, Tehran, Iran. |
| Abstract |
| Abstract Introduction: In fast-paced sports such as table tennis, athletes must rapidly shift their center of pressure (COP) to execute precise movements. This necessity embodies a fundamental motor control dilemma known as the stability–agility tradeoff: to achieve high agility, the central nervous system (CNS) must transiently reduce postural stability. (Latash, 2021) This tradeoff is implemented through feedforward modulation of motor synergies, particularly via a mechanism termed anticipatory synergy adjustment (ASA). ASA reflects a purposeful, temporary weakening of the synergy that stabilizes a performance variable, thereby enabling agile movement initiation (De et al., 2024). Methods: Twenty participants (10 skilled, 10 novice) completed 20 trials of forehand strokes while electromyographic (EMG) activity from 14 muscles and COP displacement were recorded. Using the Uncontrolled Manifold (UCM) hypothesis framework, ASA was quantified as the reduction in the normalized synergy index (ΔVZ). Pearson correlation analyses were employed to assess the relationship between athletes ASA and agility metrics (peak COP velocity and displacement magnitude). Results: Results revealed that among skilled players, both earlier onset and greater ASA amplitude were strongly and positively correlated with postural agility indicators—specifically, higher peak COP velocity (r = 0.801–0.810, p < 0.01) and greater COP displacement magnitude (r = 0.689–0.818, p < 0.05). Conclusion: These findings underscore that the stability–agility tradeoff is shaped by motor expertise. Skilled athletes strategically weaken postural synergies earlier and more substantially to prioritize movement speed over momentary balance, reflecting an advanced, feedforward control strategy (Klous et al., 2011; Naik et al., 2024). Thus, expertise enhances the CNS’s capacity to dynamically regulate the stability–agility tradeoff through precisely timed and scaled ASA, enabling superior agility without compromising task performance. |
| Keywords |
| Agility- stability trade-off, Synergy, Center of Pressure |
| Status: Abstract Accepted (Oral Presentation) |
