An evaluation of end-point trajectory planning during skilled kicking

Area of Science:

• Motor control
• Cognitive psychology
• Sports science

Background:

• Action planning is influenced by prior practice.
• Anticipating external action effects is crucial for performance.
• The common-coding hypothesis suggests shared representations for perception and action.

Purpose of the Study:

• To investigate whether planning actions based on external effects (ball trajectory) or body movements impacts soccer kicking accuracy and kinematics.
• To examine the role of visual feedback and player skill level (novice vs. skilled) in action planning.
• To provide evidence for or against the common-coding hypothesis of action planning.

Main Methods:

• Experiment 1: Skilled soccer players performed kicking tasks with external (ball) or internal (body) focus, with and without visual error feedback.
• Experiment 2: Skilled and novice soccer players performed kicking tasks with external or internal focus, without visual feedback, including a control condition.
• Performance was assessed via accuracy and movement kinematics; subjective reports on planning "normalcy" were collected.

Main Results:

• When visual feedback was withheld, an external (ball) focus led to more accurate kicking than an internal (body) focus for both skilled and novice players.
• With visual feedback, no difference in accuracy was observed between focus conditions.
• An external focus was generally more beneficial for movement kinematics, and skilled players found this focus felt more natural.

Conclusions:

• Actions are planned in terms of their external effects, supporting the common-coding hypothesis.
• The benefit of external focus is more pronounced without visual feedback and for skilled performers.
• Focusing on external outcomes enhances motor performance and feels more intuitive.