One Strap or Two: Backpack Carry Lab

A partner lab comparing a loaded backpack on one shoulder, on both shoulders with straps adjusted, and carried by hand, along a course with a zigzag, a turn, and a wait. It builds good posture, peer observation, and healthy carrying habits.

How to play

1. Partners share a backpack with 4-5 kg (9-11 lb) of books, about a school day's load. Set up a 40 m cone course: zigzag, 180-degree turn, and a 20-second standing wait (3 min).
2. Condition A: 2 laps with the pack on one shoulder. The observer watches from the side and behind for tilted shoulders, forward head, and an arched back. Switch roles (4 min).
3. Condition B: 2 laps with both straps tightened, the pack snug against the back and above the waist (4 min).
4. Condition C: 2 laps carrying it by hand, switching hands halfway (4 min).
5. After each condition, the carrier describes in one word how their shoulders and lower back feel.
6. Debrief (5 min): agree on five tips: reasonable weight, tight straps, heavy items close to the back, carry only what you need, and lift it by bending your knees.

Rules

• Maximum load of 5 kg (11 lb).
• Walk, don't run, so the observer can see.
• Safety: lift the pack off the floor by bending your knees and keeping it close.

Variations

Adaptations

• Limited mobility: compare the pack hung on the wheelchair, on the lap, or cross-body.
• Visual impairment: the observer describes aloud and guides with a hand on the shoulder.
• Fitness level: adjust the load between 2 and 5 kg (4-11 lb).

Learning goals

• Identify how each carrying method affects posture.
• Adjust one's own backpack correctly.
• Suggest healthy habits for carrying school supplies.

Equipment for a class of 25

• backpacks: 13
• books: 40
• cones: 10

Teacher tip

Ask students to bring their backpack and a few books, and keep spares handy. Don't weigh students: the focus is technique, not body weight.

More main activities for High School