A–B. Health and Safety; Technological Development, Impacts, and Careers · Technology Fundamentals, Safety and Connections

Healthy Bodies and Minds: Ergonomics, Lifting and Well-Being

A4.4About 65 minutes

Learning goals

I can set up a workstation that fits my body.
I can lift and carry safely.
I can describe daily habits that protect my physical health.
I can describe ways to protect mental health and where to get help.

Words to know

repetitive strain injury
An injury caused by repeating the same motion or posture many times.

workstation
The place and equipment where a person works, such as a desk, chair and computer.

neutral posture
A relaxed body position with joints in their natural, comfortable alignment.

stress
The body's and mind's reaction to pressure or challenge.

well-being
Being healthy and comfortable in body and mind.

harassment
Unwelcome comments or actions that a person knows, or should know, are unwelcome.

Hook: the 4-hour project

Kai spends a Saturday afternoon designing a model in a CAD program on a laptop at the kitchen table, then moves straight on to building it by hand. By evening Kai has a stiff neck, sore eyes, a headache and feels grumpy and stressed because the project is not finished.

Nothing dramatic happened, but Kai's body and mind were both under strain. Health and safety is not only about preventing sudden injuries. It is also about daily habits that protect your physical and mental health and well-being over months and years.

Physical health: ergonomics at your workstation

Many technology jobs involve hours at a computer, a workbench, a salon chair or a kitchen counter. Small posture problems repeated thousands of times can lead to repetitive strain injuries, such as sore wrists, necks and backs.

For seated computer work:

Feet flat on the floor (or a footrest), knees about level with hips.
Back supported by the chair.
Elbows bent about 90° and close to your sides; wrists straight, not bent up or down.
Top of the screen at or slightly below eye level, about an arm's length away. A laptop on a table is usually too low; raise it and use a separate keyboard if you can.

For standing work, the work surface should be near elbow height for light work, a little lower for heavy work (like kneading dough or sanding), and a little higher for fine, precise work.

Adjust the chair, screen and keyboard to fit you, not the other way around. That is ergonomics in action.

Moving and lifting

Back injuries are among the most common workplace injuries. Before lifting, ask: Do I need to lift this at all? Can I use a cart, a dolly or a second person? If you do lift:

Plan: check the weight and path; clear the way. Stand close to the load with feet shoulder-width apart.
Bend your knees and keep your back straight.
Lift with your legs, holding the load close to your body.
Turn by moving your feet, not by twisting your back. Set the load down by bending your knees.

Safe lifting: close, knees bent, load near the body, turn with your feet. Heavy or awkward loads need a cart or a partner.

Habits that protect your body

Take breaks. Short movement breaks every 30 to 60 minutes help muscles and focus. Change tasks when you can.
Rest your eyes. A common guideline is the 20-20-20 rule: every 20 minutes, look at something about 20 feet (6 m) away for 20 seconds.
Drink water and eat regularly, especially in hot shops or kitchens.
Sleep. Canada's movement guidelines recommend 8 to 10 hours of sleep a night for teens aged 14 to 17. Tired people make more mistakes.
Protect your hearing and skin with the PPE from the last lesson.
Never use tools or machines when you are very tired, ill or impaired by alcohol, cannabis or medicine that causes drowsiness.

Mental health and well-being

Mental health is part of health and safety. Ontario's law requires employers to have policies on workplace violence and harassment, and everyone deserves a respectful workplace and classroom.

Stress is a normal reaction to pressure; a little can help you focus. Long-lasting stress can harm sleep, mood, concentration and safety.
Healthy strategies: break big projects into small steps, plan your time, take breaks, move your body, breathe slowly, talk to someone you trust, and keep time for friends and things you enjoy.
Ask for help early. A teacher, guidance counsellor, family member or coach can help. Kids Help Phone is free, confidential and open 24/7: call 1-800-668-6868 or text CONNECT to 686868.
Respect others: no put-downs, no exclusion, no harassment. Report bullying or harassment to a teacher or supervisor.

Worked example

Let's fix Kai's Saturday

Plan a healthier version of Kai's 4-hour project afternoon.

Workstation: move the laptop onto a stack of sturdy books so the top of the screen is near eye level; use a separate keyboard and mouse; adjust the chair so feet are flat.
Breaks: set a timer. Every 20 minutes, look out the window for 20 seconds. Every 45 to 60 minutes, stand up, stretch and get water.
Mix tasks: alternate 45 minutes of CAD with 30 minutes of hands-on building, so different muscles and eyes get a rest.
Stress: list the steps of the project and set a realistic goal for today ("finish the design and cut the base"), instead of "finish everything."
End of day: clean up, note what to do next time, and do something relaxing before bed.

Kai's plan protects the body (ergonomics, breaks, eyes) and the mind (realistic goals, task variety, rest). The project still gets done, often better.

Just for fun

Your "funny bone" is not a bone at all. It is the ulnar nerve, which runs along the inside of your elbow. That zing when you bump it is a nerve, not a laugh.

Hands-on activity

Set up your workstation and design a break routine

You need: the place where you usually do homework, a measuring tape, books or a box to raise a screen, a timer.

Sit at your usual spot. Use the diagram's checklist (feet, knees, back, elbows, wrists, screen height and distance). Record what fits and what does not.
Make two changes that improve the fit (for example, raise the screen, add a footrest, add a cushion for back support).
Measure and record: your elbow height when sitting, the desk height, and the distance from your eyes to the screen.
Design a 5-minute break routine with at least four gentle stretches (neck, shoulders, wrists, back) and the 20-20-20 eye break. Try it after 45 minutes of work. Stretch gently and stop if anything hurts.
Write a short stress plan for your next big project: break it into steps, set a schedule, and name one person you could ask for help.

Your turn

Give three features of a healthy seated computer posture.

What is the 20-20-20 rule?

Describe the four safe lifting steps.

How many hours of sleep are recommended for 14- to 17-year-olds?

Name two healthy ways to manage stress during a big project.

Why should no one use a power tool while very tired?

More practice: warm-up

What is a repetitive strain injury?

Should you twist your back when carrying a heavy box?

Where should the top of your computer screen be?

Name one person at school you could ask for help with stress.

What is Kids Help Phone's text number?

More practice: on your own

A laptop sits flat on a kitchen table. Explain the ergonomic problem and two fixes.

A baker kneads dough on a counter that is at elbow height. Is that ideal? Explain.

Why are mental health and physical safety connected at work? Give an example.

What does Ontario's law require employers to have about workplace violence and harassment?

A friend says breaks waste time. Give two reasons breaks can make a project go better.

Challenge

Choose a job in one technology area (for example, hairstylist, cook, CAD drafter, auto technician). Identify two physical and one mental-health risk, and propose a habit or change for each.

Design a one-page "Healthy Workstation" poster for a computer lab. List what you would include and explain why each item belongs.

Explain how the hierarchy of controls applies to ergonomic hazards, using a warehouse as the example.

Check your understanding

Quiz

For seated computer work, the top of the screen should be...

When carrying a heavy load and you need to change direction, you should...

The 20-20-20 rule is for...

Which is a healthy way to handle stress on a big project?

Kids Help Phone can be reached by...

A work surface for heavy work like kneading dough should be...

For parents and teachers

This lesson links ergonomics to everyday homework habits, so it is a great chance to improve your teen's study space together. Raising a laptop on books and adding a separate keyboard costs little and helps a lot.

The mental health section is general wellness, not a diagnosis tool. If your teen seems persistently stressed, withdrawn or unhappy, talk with them and with the school guidance office. Kids Help Phone (1-800-668-6868, or text CONNECT to 686868) is available any time. Stretches in the activity should be gentle; your teen should stop any stretch that causes pain.