Classification of Motor Skills: Key Concepts and Taxonomies

Key Definitions and Why They Matter

• Motor learning and motor control are core terms in this course; definitions shape how we study and teach movement skills.
• Motor learning: the acquisition, enhancement, or reacquisition of a motor skill; includes learning a new skill, refining an existing one, or rehabilitating a lost skill after injury or illness.
• Motor control: the neuromuscular systems that activate and coordinate muscles, joints, and limbs to perform a motor skill; focuses on the neural and physiological mechanisms of coordination.
• Motor development: concerns the typical development of movement across the lifespan (e.g., sitting, crawling, standing, walking, running) in typically developing children; not the focus of this course.
• Movements vs motor skills:
  • Movements: the component parts or movements that make up a skill (the how of moving joints and limbs).
  • Motor skills: voluntary, goal-directed actions learned through motor learning; involve deliberate control of movements to achieve a specific outcome.
• Motor skills typically have a desired outcome or end product; success is judged by achieving the goal of the skill.
• Why distinguish movements from motor skills?
  • Different movements can achieve the same goal; understanding this allows tailoring of instructions to individual needs (age, condition, ability, etc.).
  • Example: a child vs a grown adult climbing stairs uses different movement strategies to reach the same outcome.
• Everyday vs elite: motor skills span everyday activities (holding, lifting, brushing teeth) to highly trained elite athletic skills; performance can be assessed across this spectrum.

Components and Domains Involved in Motor Skill Performance

• Motor skill execution relies on three interacting domains:
  • Cognitive domain: knowing what to do and how to do it; includes knowledge and cognitive processing required to perform the skill and remember the steps.
  • Perceptual domain: detecting and interpreting sensory information in the environment; identifying what is important to attend to and how to respond.
  • Motor domain: the actual execution of movement; performing the skill correctly through coordinated movement of body segments.
• Interplay among domains influences skill learning and performance (e.g., understanding the task (cognition), sensing cues (perception), and executing precise movements (motor)).

Factors Influencing Motor Skill Performance

• Three broad factors: the person, the task, and the environment.
• The Person (individual attributes):
  • Short-term: day-to-day factors like fatigue, mood, motivation, confidence, health status.
  • Long-term: age-related differences; some attributes cannot be changed about the person.
  • All these attributes influence how someone learns and performs a skill.
• The Task: goals, demands, and perceptual requirements of the skill; some tasks may be beyond an individual’s capability while others may be within reach.
• The Environment: context in which the skill is performed; includes physical surface, presence of objects, other people, and broader contextual factors (e.g., competition vs training, high-stakes vs low-stakes settings).
• Practical takeaway: when designing instruction, consider adjusting the task and environment to accommodate individual differences and optimize learning and performance.

Classifying Motor Skills: One-Dimensional Systems

• Two broad one-dimensional approaches:
  1) Size of the primary musculature (fine vs gross motor skills).
  2) Temporal/predictability features (discrete, serial, continuous).
  3) Environment stability (closed vs open) is also discussed within the one-dimensional framework.
• Size of musculature:
  • Fine motor skills: rely on small, precise muscle groups (hands, fingers, forearms); require dexterity.
  • Examples: threading a needle, knitting, drawing, sewing, screwing a lid on a bottle.
  • Gross motor skills: involve large muscle groups and possibly whole-body movement; typically require more force.
  • Examples: walking, running, jumping, swimming; fundamental gross skills learned in childhood (walking, running, jumping, throwing).
  • Continuum: skills are viewed along a spectrum from fine to gross; many real-world skills combine both fine and gross elements (e.g., steering a car, taping an ankle, putting in golf, shooting pool).
• Temporal/predictability (timing features):
  • Discrete skills: clear beginning and end; action is completed quickly; success judged as you either achieved the goal or not.
  • Examples: throwing a ball, kicking a ball, serving a tennis ball, flipping a coin, catching a ball, throwing a dart.
  • Serial skills: a sequence of discrete skills linked together to perform a more complex task.
  • Examples: triple jump (three discrete jumps), paddle boarding, changing gears in a manual car, playing the drums.
  • Continuous skills: no clear start or end point; action is ongoing or repetitive.
  • Examples: running, swimming, cycling, brushing teeth, rowing a canoe.
• Environment stability (one-dimensional view): closed vs open skills
  • Closed motor skills: stable, predictable environment; no external disturbances; object and other people are stationary; self-paced.
  • Examples: tee-ball hitting (ball stationary), free-throw in basketball, typing on a keyboard, springboard diving, painting.
  • Open motor skills: environment is unpredictable and externally paced; surface and/or objects may move; other people may be moving; you must respond to changes.
  • Examples: mountain biking, wrestling, driving on a busy road, defending a goal in ice hockey, navigating in a crowded hallway.
  • In-between examples (semi-open or semi-predictable): some intertrial variability but some predictability (e.g., chopp ing wood, driving on a quiet road, passing a basketball in a game).
• Implications for instruction and assessment:
  • Different classifications imply different learning processes and instructional strategies.
  • When planning practice and progression, align tasks with the learner’s current skill level and context (closed to open, discrete to continuous, fine to gross).

Gentiles Taxonomy: A Two-Dimensional System

• Rationale: one-dimensional systems don’t capture the complexity of many real-life skills or rehabilitation tasks.
• Two dimensions:
  • Environment (regulatory conditions): what aspects of the environment must be controlled to perform the skill?
  • Action requirements: what are the bodily movements and possible object interactions involved?
• Environmental dimension (Regulatory conditions and sources of variability):
  • Stationary regulatory conditions: little to no intertrial variability; the environment is predictable from trial to trial (closed skill characteristics).
  • In-motion regulatory conditions: the environment changes during execution; there is intertrial variability (open skill characteristics).
  • Example distinctions:
  • Closed with no intertrial variability: free throws from the same spot, typing on a keyboard, painting a picture.
  • Closed with intertrial variability: golfing shots from different positions but the player controls the initiation.
  • Open with no intertrial variability: tennis ball machine serving at constant speed and angle; treadmill walking with fixed speed.
  • Open with intertrial variability: tennis rally in a game; walking through a crowded hallway with others moving.
• Action requirements dimension:
  • Body transport vs body remains in place (transport vs stationary).
  • Object manipulation vs no object manipulation (e.g., throwing, catching, kicking vs not).
  • Examples:
  • Transport + manipulating object: dribbling a basketball while moving; kicking and passing a ball while moving.
  • Non-transport + manipulating object: archery (shooting while standing, holding a bow and arrow but not moving).
  • Non-transport + no object: single-leg balance (standing still with no object involved).
• Using Gentiles taxonomy in practice:
  • Provides a framework to assess movement problems after injury or illness and identify functionally appropriate activities for rehabilitation.
  • Helps clinicians select progression steps from the simplest to more complex tasks as patients improve.
  • Allows charting progress over time and evaluating the effectiveness of interventions.
• Notable takeaway: each category in the taxonomy places different demands on the individual; the more complex the category, the more variables must be controlled and the more challenging the task.

Practical Implications for Practitioners

• Role distinctions and application in health professions:
  • Occupational therapists (OTs): often focus on fine motor skills required for daily living activities (ADLs) and instrumental activities of daily living (IADLs); may modify tasks to accommodate deficits.
  • Exercise physiologists and physiotherapists: more often work with gross motor skills and overall movement patterns; design rehabilitation and conditioning programs to improve larger muscle group function.
  • In this course, you will likely operate primarily in contexts that address gross motor skills, while recognizing the importance of fine motor skill aspects for functional tasks.
• Assessment and progression:
  • Use classifications (one-dimensional and Gentiles taxonomy) to select appropriate tasks and progressions.
  • Evaluate how person, task, and environment interact to influence performance and learning.
  • Track changes over time to monitor rehabilitation progress and adjust interventions accordingly.
• Everyday relevance and ethical considerations:
  • Tailor movement instruction to individual contexts, ensuring safety and feasibility for diverse populations.
  • Recognize that different individuals may require different movement solutions to achieve the same skill outcome; prioritize inclusivity and adaptability.

Measurement of Motor Skill Performance

• Motor skill performance can be measured across several dimensions, including:
  • Movement quality: how well the movement pattern is executed; smoothness, coordination, control.
  • Speed: how quickly the skill is performed or how quickly a task is completed.
  • Range of motion: the extent of joint movement achieved during the skill.
  • Accuracy and error rate: how close outcomes are to the target or goal.
  • Consistency and repeatability: how stable performance is across trials or days.
• The lecturer notes that there are multiple ways to measure performance and that these measurements will be elaborated in subsequent weeks.

Summary of Key Takeaways

• Clear definitions of motor learning, motor control, motor development, movements, and motor skills are foundational for studying and teaching movement.
• Distinguishing between movements and motor skills enables tailored instruction to individual needs and circumstances.
• Skill performance is influenced by the person, the task, and the environment; all three must be considered in instruction and rehabilitation.
• Classification of motor skills can be approached using one-dimensional systems (muscle size, temporal features, environment stability) or two-dimensional systems ( Gentiles taxonomy) that consider environment and action requirements.
• Gentiles taxonomy provides a detailed framework for assessing movement problems and guiding rehabilitation progress, with practical applications for therapy and training.
• Measurements of motor skill performance involve multiple dimensions (quality, speed, ROM, accuracy, consistency), and ongoing assessment informs program adjustments.

Connections to Practice and Real-World Relevance

• When designing movement training or rehabilitation programs, start from simpler, closed, discrete, fine or gross skills and progressively introduce variability and open environments as the learner improves.
• Consider the learner’s current state (fatigue, motivation, health) and the task demands when selecting practice activities to maximize safety and learning.
• Use a structured taxonomy (Gentiles) to chart progress and communicate goals with clients, colleagues, and stakeholders.
• Recognize that everyday tasks and elite performance share underlying principles of motor learning and control, enabling transfer of coaching and rehabilitation strategies across contexts.