Phone Video Ergonomics for Safer Chore Tasks

ISEF Category: Engineering Technology: Statics and Dynamics

Subcategory: Industrial Engineering-Processing  ·  Difficulty: Intermediate  ·  Setup: Home Setup  ·  Time: 1 to 2 Months

The Hook

Your body keeps score during chores. A bad handle angle can make you twist, reach, and strain without noticing. That hidden stress shows up in posture scores like RULA and REBA. With a phone camera, you can measure it, then test whether a smarter tool design lowers the risk.

What Is It?

This project studies how your body moves during everyday tasks, like sweeping, peeling, mopping, or stirring. Ergonomics is the science of fitting tools and jobs to people, so you do less awkward bending, reaching, and twisting. RULA and REBA are scoring systems that turn posture into numbers. Higher scores mean more strain risk.

OpenPose helps you estimate body joint positions from video. Think of it like a stick-figure tracker that follows elbows, shoulders, knees, and hips. You can record a task, score the posture, then change one tool feature, like handle angle, grip size, or tool length, and see whether the score improves. The key idea is simple, if the body looks less contorted on video, the risk score should drop too.

Why This Is a Good Topic

This is a strong science fair topic because you can test one design change at a time and measure the result with clear numbers. It connects to a real problem, repetitive strain from chores and work tasks, which affects comfort, safety, and long-term injury risk. You can learn video analysis, human factors thinking, and data comparison without needing a lab full of equipment.

Research Questions

• How does handle angle affect RULA scores during a household sweeping task?
• How does tool length change REBA scores during mopping or reaching tasks?
• Does adding a larger grip diameter reduce wrist deviation during a repeated hand task?
• To what extent does changing the angle of a scraper handle lower shoulder elevation during use?
• Which tool geometry, handle angle, handle length, or grip size, produces the lowest posture risk score for a chosen chore?
• How does dominant hand versus non-dominant hand use change posture scores for the same task?

Basic Materials

• Smartphone with a camera and stable video settings.
• Tripod or phone stand.
• Household chore tools such as broom, mop, scraper, or spatula.
• Masking tape or markers to set a repeatable task area.
• Measuring tape or ruler.
• Notebook or spreadsheet for scoring and comparisons.
• Consent form or parent permission if you record other people.

Advanced Materials

• Smartphone with high-resolution video and manual exposure control.
• Laptop with Python installed.
• OpenPose or MediaPipe for pose estimation.
• ImageJ for frame checks and motion analysis.
• Spreadsheet software or a stats package for repeated-measures analysis.
• 3D printer, foam, or basic workshop tools for making handle prototypes.
• Digital angle finder or protractor for verifying tool geometry.
• Force gauge or grip strength meter, if you add effort measurements.

Software & Tools

• OpenPose: Estimates body joint positions from video so you can score posture changes across task designs.
• Python: Helps you process frames, organize posture data, and automate repeated measurements.
• ImageJ: Lets you inspect video frames, verify pose tracking, and compare body angles.
• Google Sheets: Stores scores, calculates averages, and makes simple charts for each design.
• JASP: Runs t-tests, repeated-measures tests, and effect size calculations with a friendly interface.

Experiment Steps

1. Define one chore task and one body region you want to improve, such as wrist angle, shoulder height, or trunk bend.
2. Choose a single tool feature to change first, such as handle angle, handle length, or grip diameter.
3. Plan a repeatable filming setup so the same task looks as similar as possible across trials.
4. Decide how you will turn video into posture scores, then test your pose-tracking method on a few frames before collecting full data.
5. Build a comparison plan that includes a baseline tool, one redesigned version, and enough repeated trials to compare scores fairly.
6. Set up your analysis before you start, including how you will handle missing frames, noisy tracking, and repeated measurements.

Common Pitfalls

• Changing camera position between trials, which breaks pose estimates and makes posture scores hard to compare.
• Testing too many tool changes at once, which hides the effect of the one design feature you wanted to study.
• Using tasks that are too fast or too complex, which causes OpenPose to lose joints and misread posture.
• Forgetting to keep the same person, stance, or task side across trials, which adds extra variation to the scores.
• Trusting one video frame instead of repeated trials, which makes a lucky or bad posture look like a real design effect.

What Makes This Competitive

A stronger project goes beyond a simple before-and-after comparison. You can compare multiple tool geometries, use repeated-measures statistics, and report effect sizes, not just average scores. You can also test whether human judgment and OpenPose agree, which makes the project stronger and more honest. The best versions ask whether your redesign helps across different users, not just one person on one day.

Project Variations

• Study how broom handle angle changes trunk bend and shoulder load during sweeping.
• Compare three spatula grip shapes to see which one lowers wrist deviation during stirring or flipping.
• Test whether left-handed and right-handed users get different REBA scores from the same tool design.

Learn More

• PubMed: Search for review articles on ergonomic risk assessment, RULA, REBA, and musculoskeletal strain.
• NIH National Library of Medicine: Look for articles on posture, repetitive strain, and workplace ergonomics through PubMed and related databases.
• OSHA Ergonomics resources: Find practical guidance on posture, tool design, and injury risk in workplace tasks.
• MIT OpenCourseWare: Search for human factors, product design, or biomechanics course materials to learn study design ideas.
• OpenPose GitHub documentation: Read the project docs to understand pose estimation inputs, outputs, and common limitations.
• JASP: Download the software and use its help pages for repeated-measures tests and effect size analysis.