======Center of Gravity Balance Test======


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**Materials: **{{$demo.materials_description}}\\
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**Safety: **{{$demo.safety_description}}\\
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**Alternative titles:** Finding Your Center of Gravity
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====Summary====                   
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====Procedure====  
  - Choose a wide, flat curb with clear space on both sides and recruit an assistant with a stopwatch.
  - Practice standing on the curb facing the sidewalk with your heels hanging off the edge; select your challenge level (two feet still, heel raises, or one foot).
  - Prepare a data table for three experiments: arms only, short pole, and long pole; plan five timed trials for each of three positions in every experiment.
  - For Experiment 1 (arms only): balance with (A) arms at sides, (B) arms out at shoulder height, and (C) arms overhead; time each trial and note a wobble rating (slow/medium/fast).
  - For Experiment 2 (short pole): hold a short pole close to the body at (A) waist, (B) shoulder, and (C) overhead; repeat five trials per position and record time and wobble.
  - For Experiment 3 (long pole): repeat the three positions using a pole at least 2 m longer than the short pole; record time and wobble for five trials per position.
  - Between trials, step down safely, rest, and reset; keep foot placement and gaze direction consistent within an experiment.
  - Calculate average balance time for each position and a total average for each experiment; compare results to see how pole length and position affect stability.



====Links==== 
📄 Balancing Act: Finding Your Center of Gravity - Science Buddies: [[https://www.sciencebuddies.org/science-fair-projects/project-ideas/Sports_p017/sports-science/balancing-center-of-gravity]]\\


====Variations====
  * Add mass: tape equal weights (e.g., soup cans) to pole ends or hold hand weights to see how added mass changes stability and wobble.
  * Vision changes: repeat trials while turning your head, looking up, or closing one eye to test the role of visual cues in balance.
  * Moving balance: build a simple 2×4 balance beam and compare walking balance times versus standing balance times.
  * Group data: have multiple participants repeat the protocol and analyze how results vary by height, arm span, or experience.



====Safety Precautions====
  * Use a stable, dry curb away from traffic; choose a grassy or soft landing area when possible.
  * Have a spotter nearby for all trials, especially when using poles or balancing on one foot.
  * Wear closed-toe shoes with good grip; avoid loose clothing that could catch on the pole.
  * Keep the testing area clear of obstacles; ensure poles are smooth and free of splinters or sharp edges.
  * Stop immediately if you feel dizzy, unsteady beyond control, or experience pain.




====Questions to Consider====
  * How does spreading your arms out affect your center of gravity and base of support? (Arms out widen the effective base and can slightly lower/redistribute mass, improving stability.)
  * Why might a longer pole reduce wobble speed? (Increasing distance from the pivot increases rotational inertia, which slows angular acceleration and wobble.)
  * Which pole position gave the longest average times and why? (Likely at waist or shoulder height with a long pole, because mass is lower and spread horizontally, improving control.)
  * How do added end weights change balance performance? (They increase rotational inertia at the ends, resisting quick tipping and often lengthening balance time.)
  * What body systems help you balance besides muscles? (Visual, vestibular, and proprioceptive systems coordinate to keep the center of gravity over the base of support.)