Balance with the Accelerometer: Eyes Open and Closed

With the phone in a waist pack at the low back, a sensor app records body sway during 30 seconds of standing on one foot in four conditions. After a short block of balance training, students repeat the hardest test and compare.

How to play

1. Set up the sensor app with the class to record 30 seconds of acceleration and place the phone in the waist pack at the low back (3 min).
2. Test on the dominant leg in four conditions: floor with eyes open, floor with eyes closed, mat with eyes open and mat with eyes closed; the partner records the sway range shown by the app (8 min).
3. Balance training: passing a ball on one leg, foot reaches in three directions and switching surfaces (8 min).
4. Record again in the hardest condition and compare with the first try (4 min).
5. Conclusion: what role vision and surface play in balance and why it's trained after an ankle sprain (2 min).

Rules

• Your partner stays right beside you, ready to steady you if you lose balance.
• Mats are placed away from walls and other groups.
• If the other foot touches down, repeat the try.
• Everyone compares only against themselves.

Variations

Adaptations

• Recent ankle sprain: does the test in a tandem stance instead of on one foot.
• Visual impairment: compares floor and mat only, since opening or closing the eyes doesn't change their test, and a partner describes the graph.
• Wheelchair user: records trunk balance sitting without a backrest, phone strapped to the chest, while reaching for objects.

Learning goals

• Measure postural control with the phone's sensors.
• Understand how vision and surface affect balance.
• Learn balance exercises that help prevent ankle injuries.

Equipment for a class of 25

• tablets or phones: 14
• waist packs: 14
• mats: 14
• balls: 14

Teacher tip

Some sensor apps show the acceleration's standard deviation directly; otherwise reading the range between maximum and minimum is enough. Make sure everyone uses the same app settings.

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