KIN251 final exam

What are the criteria used to define motor learning?

Motor learning is identified by:

• A relatively permanent change in movement behavior

• Resulting from practice or experience

• Not due to maturation, fatigue, or temporary states

• Measured through retention and transfer tests, not just performance

What are the three stages of motor learning, and what characterizes each stage?

• Cognitive stage

  • Learner is figuring out what to do

  • Lots of errors, high attention demand

  • Reliance on feedback and instructions

• Associative stage

  • Refining movement patterns

  • Fewer errors, more consistency

  • Begins to detect and correct mistakes

• Autonomous stage

  • Skill becomes automatic

  • Low attention demand

  • Can perform while multitasking

What do performance curves show, and how does the law of practice explain them?

• Performance curves show improvement in performance over time/practice

• Typically:

  • Rapid improvement early

  • Slower improvements later (plateau effect)

Law of practice:

• Performance improves with practice but at a decreasing rate over time

What are the limitations of using performance curves to measure learning?

• Performance ≠ learning

• Temporary factors (fatigue, motivation, feedback) affect performance

• Plateaus may hide continued learning

• Doesn’t show retention or transfer

How do transfer and retention tests help distinguish learning from performance?

• Retention test: performance after a delay without practice

  • Shows if learning is permanent

• Transfer test: performance in a new or modified task

  • Shows adaptability of learning

What is transfer of learning, and how do positive and negative transfer differ?

• Applying learned skills to new situations

• Positive transfer: improves performance in new task

  • e.g., tennis serving helps volleyball serving

• Negative transfer: interferes with performance

  • e.g., switching from golf swing to baseball swing

What is the difference between intrinsic feedback and augmented feedback?

• Intrinsic feedback:

  • Naturally comes from senses (vision, proprioception, touch)

• Augmented feedback:

  • External information provided by instructor, device, or coach

What is the difference between KR (knowledge of results), KP (knowledge of performance), and concurrent feedback?

• KR (Knowledge of Results):

  • Outcome-based (success/failure, score, distance)

• KP (Knowledge of Performance):

  • Movement quality (form, technique)

• Concurrent feedback:

  • Given during performance (real-time cues)

What are the main functions of augmented feedback during learning?

• Helps detect errors

• Guides correction

• Motivates learner

• Reinforces correct movement

• Accelerates early learning

What is the guidance hypothesis, and why can too much feedback cause dependency?

• Too much feedback → learner becomes dependent

• Learner stops processing intrinsic feedback

• Performance may drop when feedback is removed

How does the amount/precision/frequency of feedback influence learning?

• Amount: too much → dependency; too little → slow learning

• Precision: overly precise early can overwhelm learners

• Frequency: frequent helps early, reduced later improves retention

How do strategies like faded/bandwidth/summary feedback help reduce dependence on feedback?

• Faded feedback: gradually reduce feedback over time

• Bandwidth feedback: only give feedback when error exceeds threshold

• Summary feedback: give feedback after multiple trials

What are learner-determined feedback schedules, and how do they benefit learning?

• Learner chooses when they receive feedback

• Benefits:

  • Encourages self-evaluation

  • Improves error detection

  • Reduces dependency

Why do subjective estimations help reduce the negative effects of frequent feedback?

• Learner predicts their own performance before receiving feedback

• Improves:

  • Self-awareness

  • Intrinsic error detection

  • Retention

How can we interpret graphs of performance curves to distinguish between performance and learning?

• Improvement during practice = performance

• Retention/transfer = learning

• If performance improves but retention is poor → not true learning

Why do children often benefit from more frequent feedback?

• Less developed:

  • Cognitive processing

  • Error detection ability

• Need external guidance early in learning

How can robots be used effectively to facilitate motor learning?

• Provide:

  • Consistent feedback

  • Controlled practice environments

  • Repetitive training

• Useful for rehabilitation and skill acquisition

How do massed and distributed practice differ, and why is distributed practice usually more effective?

• Massed practice:

  • Little rest, long sessions

  • Leads to fatigue, lower learning

• Distributed practice:

  • Rest intervals included

  • Better retention and performance

What is the difference between variable and constant practice, and why does variable practice improve generalization?

• Constant practice:

  • Same conditions every trial

  • Good for beginners

• Variable practice:

  • Changing conditions

  • Improves adaptability and generalization

How do blocked and random practice differ (low vs. high contextual interference), and why is random practice typically more effective?

• Blocked practice:

  • Same skill repeated before switching

  • Better short-term performance

• Random practice:

  • Skills mixed randomly

  • Better long-term learning

What are “desirable difficulties,” and how do they support learning?

• Conditions that make practice harder but improve learning:

  • Random practice

  • Variable conditions

  • Reduced feedback

• Forces deeper processing and memory encoding

Why are instructions important in motor learning?

• Provide direction and reduce uncertainty

• Help structure early learning

What different modes of instruction can be used to support learning?

• Verbal cues

• Visual demonstrations

• Physical guidance

• Analogies

How does transition information help a learner improve?

• Information that helps shift from one movement stage to another

• Example: “now shift weight earlier”

How can analogies and demonstrations reduce information overload?

• Reduce cognitive load

• Help learners understand complex movements quickly

What are mirror neurons and why are they important for observational learning?

• Brain cells activated when:

  • Performing an action

  • Observing the same action

• Important for imitation and observational learning

What are the differences between learning from an expert model vs. a novice model?

• Expert model:

  • Shows ideal technique

  • Can be too complex for beginners

• Novice model:

  • Shows common errors

  • Helps learners understand what NOT to d

What is the difference between internal and external focus of attention?

• Internal focus: body movement (e.g., “move your arm”)

• External focus: effect of movement (e.g., “aim the ball”)

How can an internal focus contribute to “choking” under pressure?

• Increases conscious control of automatic skills

• Disrupts fluid execution under pressure

How can manipulating constraints be used to alter movement patterns?

Changing:

• Task (rules, equipment)

• Environment (space, surface)

• Individual (strength, flexibility)

Purpose:

• Shape movement patterns naturally without explicit instructions

Why do we study human movement?

• Improve performance (sports, training)

• Prevent injury

• Rehab and clinical applications

• Understand how the body produces motion

What are the three main “lenses” used to study movement?

• Biomechanics → forces & motion (physics side)

• Motor control/learning → how we learn & control movement

• Exercise physiology → energy systems & body responses

What are the fundamental units used in mechanics?

• Length → meters (m)

• Mass → kilograms (kg)

• Time → seconds (s)

How do you convert between different units in biomechanics?

Use conversion factors (ratios equal to 1) to cancel units step-by-step.

Length

• 1 m = 100 cm

• 1 m = 1000 mm

• 1 km = 1000 m

• 1 in = 2.54 cm

• 1 ft = 0.3048 m (or 12 in)

Mass

• 1 kg = 1000 g

• 1 g = 0.001 kg

• 1 lb ≈ 0.454 kg

Time

• 1 min = 60 s

• 1 hr = 3600 s

What is the difference between vectors and scalars? What quantities are vectors and scalars?

• Scalars → magnitude only (speed, mass, time)

• Vectors → magnitude + direction (velocity, force, acceleration)

What rules govern vector addition?

• Tip-to-tail method

• Parallelogram method

• Components method (most useful)

How do you resolve a vector into its horizontal and vertical components?

• Horizontal: V_x=Vcos⁡θ

• Vertical: V_y=Vsin⁡θ

How can the slope of a graph be used to interpret average/instantaneous rates of change?

• Position–time → slope = velocity

• Velocity–time → slope = acceleration

• Steeper slope = faster rate of change

What is a projectile and what is the path followed by a projectile?

• Object in flight under gravity only

• Path = parabolic

What are the three key parameters (speed, angle, height) that determine projectile motion?

• Speed

• Angle

• Height

How does each parameter influence the horizontal distance a projectile travels?

• ↑ speed → ↑ distance

• Angle ~45° gives max distance in theory

• ↑ release height → ↑ distance

Why is the optimal projection angle in sports often not 45 degrees?

• Release height isn’t zero

• Air resistance

• Human body mechanics → harder to generate force at 45°

What are angular kinematics, and how can we describe angular motion using planes and axes of motion?

Angular kinematics

• Rotation around an axis

• Described using planes & axes

What major arm and leg motions occur in the frontal, sagittal, and transverse planes?

Planes of motion

• Sagittal → flexion/extension (running, jumping)

• Frontal → abduction/adduction (jumping jacks)

• Transverse → rotation (throwing, swinging)

How are linear velocity and angular velocity related?

v=rω

• v (linear velocity) = straight-line speed of a point

• ω (angular velocity) = rotational speed

• r = distance from axis of rotation

Key idea:

• Farther from axis → higher linear speed

• Same rotation, different points move at different speeds

How can these principles be applied in real-world tasks?

• Sports technique improvement

  • Optimize throwing, kicking, swinging mechanics

• Injury prevention

  • Identify unsafe joint angles or excessive rotation

• Performance enhancement

  • Increase angular velocity through better sequencing (hips → trunk → arm)

• Rehabilitation

  • Restore normal movement patterns after injury

• Coaching & analysis

  • Break down skill errors using plane-based movement analysis

What are the key steps in conducting a kinematic analysis?

• Identify the movement/task (e.g., jump, throw, sprint)

• Break into phases (preparation, execution, follow-through)

• Choose variables (angle, velocity, displacement, time)

• Collect or estimate data (video analysis, observation)

• Interpret results (what improved or limited performance?)

What is the impulse–momentum relationship?

Impulse=F⋅t=Δp=m(v_f​−v_i​)

• Impulse = force applied over time

• Equals change in momentum

How is impulse used to increase or decrease momentum in movement tasks?

• Increase momentum (more performance):

  • Apply force for longer time

  • Example: follow-through in throwing or kicking increases ball speed

• Decrease momentum (safety/control):

  • Increase time of impact to reduce force

  • Example: bending knees when landing reduces impact forces

How are Newton’s laws applied specifically in real-world tasks?

• Running: pushing against ground (3rd law) produces forward motion

• Jumping: force applied downward → body goes upward

• Lifting weights: more force needed for heavier loads (2nd law)

• Stopping/turning: inertia explains why quick direction changes are hard

• Sports equipment use: bats, racquets amplify force through mechanics

How is the impulse–momentum relationship used when designing safety equipment?

Goal: reduce peak force during impact

• Increase time of impact (t) → lowers force

  • Helmets, airbags, crash pads

• Spread force over longer duration

• Convert sudden impact into slower deceleration

Example:

• Without helmet: head stops instantly → high force

• With helmet: longer stopping time → lower force → less injury

What is torque, and how does the moment arm influence it?

rque (τ) = rotational force that causes an object to turn

τ=r×F

• r = moment arm (distance from axis of rotation to where force is applied)

• Bigger moment arm → more torque

• Force applied farther from joint = easier rotation

Human example:

• Swinging a bat farther from your hands → more torque → harder hit

What is moment of inertia, and what factors affect it?

Moment of inertia (I) = resistance to rotational motion

• Depends on:

  • Mass

  • Distribution of mass relative to axis

Key idea:

• Mass farther from axis → ↑ inertia → harder to rotate

• Mass closer to axis → ↓ inertia → easier to rotate

What is the center of gravity, and what factors influence its location?

COG = point where body’s mass is evenly balanced

What affects its location:

• Body position (arms/legs moving changes it)

• Body shape/posture

• Distribution of mass

How does the center of gravity affect stability?

Stability depends on:

• Lower COG = more stable

• Wider base of support = more stable

• COG inside base of support = stable

• If COG moves outside base → loss of balance/fall

How is moment of inertia applied in gymnastics movements?

• Tuck position: mass closer to axis → ↓ inertia → faster spin

• Pike position: moderate inertia → medium speed

• Layout (extended): ↑ inertia → slower rotation

Key idea: gymnasts control spin speed by changing body shape

How does the center of gravity influence jumping techniques, and why do some techniques enhance performance?

• Jumping height depends on force production, but:

• Body position changes how height is used visually and functionally

Why techniques differ:

• Arm swing → shifts COG and increases upward momentum

• Tucking legs → helps rotation in flips

• Arching/extension → controls rotation timing in air

Big idea:

• Better technique = more efficient use of force, not just more force

How can these concepts be applied in real-world tasks?

Sports

• Throwing, swinging, jumping, diving, gymnastics

• Adjusting body position to control speed, power, and rotation

Injury prevention

• Poor torque control → joint stress (knees, shoulders)

• Proper alignment reduces rotational strain

Everyday movement

• Lifting: keep objects close → reduces torque on spine

• Carrying: balance and COG control stability

• Walking/running: controlled COG shift improves efficiency

What are the key characteristics of skilled performance?

• Consistent

• Accurate

• Efficient (low wasted movement)

• Adaptable to changing environments

How do open and closed skills differ?

• Closed skills: stable environment, predictable

  • ex: bowling, darts

• Open skills: changing environment, unpredictable

  • ex: soccer, basketball defense

What distinguishes discrete, serial, and continuous skills?

• Discrete: clear start/end (throw, kick)

• Serial: sequence of discrete actions (gymnastics routine)

• Continuous: no clear start/end (running, cycling)

What do CE (Constant Error), AE (Absolute Error), VE (Variable Error), and RMSE (Root Mean Square Error) measure in motor performance? What contexts are they used?

• CE (Constant Error): direction of error (bias)
  → are you consistently too high/low?

• AE (Absolute Error): overall accuracy
  → how far off regardless of direction

• VE (Variable Error): consistency
  → how spread out your attempts are

• RMSE: overall performance error combining bias + variability
  → used in modeling / labs / data analysis

Can you estimate CE, AE, VE if provided a distribution of points from an experiment?

CE (Constant Error)
Bias (direction of error: too high or too low)
CE = Σ(score − target) / n

AE (Absolute Error)
Accuracy (size of error, ignores direction)
AE = Σ|score − target| / n

VE (Variable Error)
Consistency (how spread out scores are)
High VE = inconsistent performance

RMSE
Overall error (combines bias + variability)
RMSE = √[Σ(score − target)² / n]

What are the stages in the information processing model for human performance?

Information processing stages

1. Stimulus identification

2. Response selection

3. Response programming

4. Movement execution

More choices = slower decision-making

What is the difference between reaction time, movement time, and response time?

• Reaction time: stimulus → movement start

• Movement time: movement start → completion

• Response time: total = reaction + movement

What does Hick’s Law tell us about reaction time and decision-making? What is the shape of the curve in Hick’s law?

• More choices → longer reaction time

• Relationship is logarithmic curve (slows down, not linear)

How does stimulus-response compatibility affect reaction time? How can we deal with S- R incompatibility?

• Compatible = faster reaction

• Incompatible = slower reaction

Fixing incompatibility:

• training

• better mapping (design/positioning)

• consistent spatial alignment

How can anticipation reduce reaction time?

• Predicting stimulus before it happens

• Reduces reaction time significantly

• Used in sports (goalkeepers, batters)

What is the speed-accuracy tradeoff, and how is it explained by Fitts’ Law?

Fitts’ Law

• Faster movement = less accuracy

MT=a+blog⁡₂(2D/W)

• D = distance

• W = target width

What are the “independent” and “dependent” variables involved in Fitts’ law? - what do the slope and intercept in Fitts’ Law represent?

• Independent: difficulty (distance, size)

• Dependent: movement time

Why does increasing speed typically reduce accuracy in spatial tasks?

• Slope (b): sensitivity to task difficulty

• Intercept (a): baseline processing/movement time

Less time for feedback correction

Higher variability in motor output

How is Fitts’ Law applied in computer interface design?

• Bigger buttons = easier clicking

• Closer targets = faster interaction

• Menu design minimizes travel distance

What is the speed-accuracy relation in temporal (or timing) tasks?

• Tradeoff also exists in timing (rhythm, pacing)

• More precision in timing = slower performance

Why are tasks like hitting a baseball that involve both spatial and temporal constraints challenging? How do athletes deal with such constraints?

• Require BOTH spatial + timing accuracy

• Athletes solve this by:

  • anticipation

  • training automatization

  • predictive control

What are the defining characteristics of closed-loop control?

• Uses feedback during movement

• Adjusts in real time

• Good for slow/precise movements

What components make up a closed-loop control system?

• Executive (motor command)

• Effector (muscles)

• Feedback system (vision, proprioception)

• Comparator (detects error)

What types of sensory feedback do humans use in movement control?

• Visual

• Proprioceptive (body position)

• Auditory (sometimes)

What are the two visual streams, and how do they contribute to movement?

• Dorsal stream: “where/how” → movement guidance

• Ventral stream: “what” → object identification

What is optic flow?

• Dorsal stream: “where/how” → movement guidance

• Ventral stream: “what” → object identification

How does proprioception contribute to reflexive control?

• Body position sense

• Enables reflex corrections

What are the advantages and disadvantages of closed-loop control?

• Pros: accurate, adaptable

• Cons: slow, requires feedback time

What are the characteristics of open-loop control?

• No feedback during movement

• Pre-programmed action

• Fast execution

What are the pros and cons of using open-loop control?

• Pros: fast, efficient for rapid movements

• Cons: cannot correct during execution

What is a motor program, and what evidence supports its existence?

• Stored movement pattern in CNS

• Evidence: same movement can be performed without feedback

How does learning occur in open-loop control systems?

• Learning = improving the motor program

• Happens through practice + repetition

• Feedback is used after the movement (not during)

• Over time:

  • movements become more automatic

  • less conscious control is needed

  • errors get reduced by updating the stored program

What is a Generalized Motor Program (GMP), and what evidence supports it?

GMP = stored “template” for a movement pattern

• Contains:

  • invariant features (same structure of movement)

  • parameters (force, speed, duration can change)

Evidence for GMP:

• Same movement can be performed at different speeds but keeps structure

• Variability in force/time doesn’t change overall pattern

• People can perform movements without real-time feedback

How can predictions act as a form of fast feedback?

• Brain predicts outcome of movement before sensory feedback arrives

• This “internal model” allows:

  • fast corrections

  • smoother control

• Important because real sensory feedback is too slow for rapid movements

How can open- and closed-loop control systems be combined?

Most movements use BOTH:

• Open-loop: fast, pre-programmed (initial movement)

• Closed-loop: feedback corrections during/after

Example:

• throwing a ball:

  • open-loop = arm acceleration

  • closed-loop = adjustments based on vision/proprioception

What does “degrees of freedom” mean in movement control?

Degrees of freedom (DOF)

• Refers to the number of independent ways a body/joint can move

• Example: shoulder alone has multiple rotational directions → many DOF

More DOF = more possible movements, but harder to control

What is the “degrees of freedom problem”?

• The nervous system must control too many muscles and joints simultaneously

• Problem: infinite movement combinations for any task

• Solution needed: simplify control into manageable units

What is context-conditioned variability, and how do anatomical, mechanical, and physiological factors contribute?

Context-conditioned variability

• Movement is not random variability—it depends on context

Contributing factors:

• Anatomical: joint structure limits motion (e.g., knee only flex/extend much)

• Mechanical: gravity, momentum, external forces change movement demands

• Physiological: fatigue, strength, neural activation patterns affect execution

Result: same task can look different depending on conditions

What are strategies to simplify the degrees of freedom problem?

• Freezing degrees of freedom (beginners stiffen joints)

• Muscle synergies (groups of muscles act together)

• Segment coordination (using fewer joints effectively)

• Progressive release of DOF (experts regain flexibility + efficiency)

How do motor plans, motor commands, and feedback contribute to postural, locomotor, and hand-eye coordination?

• Motor plan: overall strategy (what movement to do)

• Motor command: neural signals sent to muscles (how to execute)

• Feedback:

  • Postural: keeps balance upright

  • Locomotor: adjusts walking/running steps

  • Hand-eye: fine tuning reaching/aiming using vision + proprioception

How does the dynamical systems view of coordination differ from the motor program view?

• Motor program: movement is pre-stored and executed like a script

• Dynamical systems: movement emerges from interaction of:

  • body

  • environment

  • task constraints

Coordination is self-organizing, not fully pre-planned

What did Kelso’s “finger wiggling” experiment reveal about motor control?

• Participants tried to move fingers in:

  • in-phase (same direction)

  • anti-phase (opposite direction)

Finding:

• At higher speeds, anti-phase becomes unstable and switches to in-phase

Shows:

• coordination has stable and unstable patterns

• movement transitions happen naturally under constraints

What rules seem to underlie temporal coordination in bimanual tasks?

• Movements tend to:

  • synchronize timing between limbs

  • lock into rhythmic patterns

• Higher speed → less stable timing patterns

What rules seem to underlie spatial coordination in bimanual tasks?

• Limbs tend to:

  • mirror each other spatially

  • reduce asymmetry

• Symmetrical movements are more stable than asymmetric ones

How does Fitts’ Law apply to bimanual movements? How is it different from the unimanual case?

• Both hands are subject to speed–accuracy tradeoff

MT=a+blog_⁡2(2D/W)

Difference from unimanual:

• One hand can limit the other (coordination constraint)

• Increased interference between limbs

• Higher cognitive + motor demand than single-hand tasks

How can task conceptualization help overcome temporal and spatial constraints?

• Changing how you mentally define the task improves performance

  • e.g., “move one object with two hands” instead of “two separate movements”

• Reduces conflict between limbs

• Improves coordination efficiency

What are the differences between learning “part” versus “whole” in bimanual coordination?

• Part practice:

  • break movement into components

  • good for learning mechanics

  • weak for timing/coordination integration

• Whole practice:

  • practice full movement pattern

  • better for coordination, timing, and real performance

  • usually superior for bimanual skills