A motor skill is a learned action that requires movement of the body or limbs to achieve a predetermined goal. These skills are fundamental to everyday life and athletic performance, ranging from writing a signature to hitting a baseball. Motor learning scientists categorize these actions based primarily on the stability and predictability of the environment. This classification system helps distinguish how movements are planned and executed. Understanding this distinction provides a framework for analyzing performance and developing effective learning strategies.
Defining Closed Skills
Closed motor skills are executed in environments that remain stable and highly predictable. The performer is in control of the timing and initiation of the action, meaning the skill is almost entirely self-paced. This allows the movement pattern to be rehearsed and repeated as a highly consistent, fixed technique. The goal of a closed skill is to maximize efficiency and consistency. Because external conditions do not change, the performer focuses on refining the motor program to achieve near-perfect replication. Examples like a free throw or a competitive weightlifting lift illustrate this focus on precise, habitual movement execution.
Defining Open Skills
Open motor skills, conversely, are performed in dynamic, variable, and unpredictable environments. The performer must react to external stimuli that dictate the timing and nature of the movement, making the skill externally-paced. This means the movement pattern must be constantly adapted and modified in response to changing conditions. The complexity of open skills stems from high demands placed on perception and decision-making. The performer must rapidly process external cues, such as an opponent’s movement or the speed of a ball. The focus shifts from executing a fixed technique to selecting and adjusting the most appropriate response quickly.
The Skill Continuum and Real-World Examples
The classification of open versus closed exists on a spectrum called the skill continuum. At the extreme closed end are skills performed in a completely invariant setting, such as a discus throw or a golf swing executed on a flat driving range. These actions are initiated solely by the performer and are unaffected by external factors.
Moving along the continuum toward the open end, the environment introduces more variability, forcing greater adaptation. A soccer penalty kick is mostly closed, but the presence of a reactive goalkeeper introduces a small element of variability. A highly open skill requires the performer to constantly read and react to a dynamic situation, such as a defender tackling a player in rugby or a tennis player returning a fast, spinning serve.
Skills that fall in the middle often involve a stable environment but require timing an action to an object in motion. Batting in baseball is a prime example, where the batter stands in a fixed position but must time their swing to a pitch that varies in speed and trajectory. Environmental factors, like wind or water currents when steering a sailboat, also push an otherwise fixed skill toward the open end of the spectrum.
Optimizing Practice Methods
The open-closed classification has implications for how a skill should be learned and practiced. For closed skills, the optimal training method emphasizes fixed, repetitive practice to solidify the consistent motor program. Drills involving massed repetition, such as repeatedly practicing a clean and jerk lift or a bowling approach, help automate the movement sequence. This focused repetition reduces the variability between attempts, embedding an efficient technique into the performer’s motor memory.
In contrast, practicing open skills requires training that simulates the unpredictability of the performance environment. Learning is optimized through variable practice, where the conditions change from one attempt to the next, forcing continuous decision-making. For a soccer player, this means using small-sided games or reaction drills instead of isolated cone drills to improve agility and response time. This variable practice hones the performer’s perceptual skills, allowing them to interpret external stimuli and select the correct movement response under pressure.