Center of Gravity Balance Test

Balance on the edge of a curb and test how arm position and the use of short versus long poles affect stability and wobble speed. By changing where mass is distributed, you shift your center of gravity and can measure how that influences balance time.

1. Choose a wide, flat curb with clear space on both sides and recruit an assistant with a stopwatch.
2. 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).
3. 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.
4. 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).
5. 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.
6. 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.
7. Between trials, step down safely, rest, and reset; keep foot placement and gaze direction consistent within an experiment.
8. 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.

📄 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

• 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.

• 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.

• 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.)