Asymmetry Map: Left Side vs. Right Side

In pairs, students measure four single-side tests, calculate the percentage difference between sides and decide whether the asymmetry matters. They finish by trying two exercises for the more limited side.

How to play

1. General mobility work for hips, shoulders and ankles so the body is warm (4 min).
2. Explain the formula: difference (%) = (larger side − smaller side) / larger side × 100, and the rule of thumb that more than 10–15% deserves attention (3 min).
3. In pairs, measure both sides: straight leg raise with an inclinometer, seated hip internal rotation, back scratch test and seconds of single-leg balance with eyes closed (10 min).
4. Calculate the percentages on the worksheet and mark each test green, yellow or red based on the threshold (4 min).
5. Pick the biggest asymmetry and try two exercises for the limited side, such as active leg raises or balance with reaches (4 min).

Rules

• Always measure the right side first and then the left, with the same position and the same measurer.
• During eyes-closed balance, the partner stands alongside, ready to catch.
• An asymmetry is not an injury: read it alongside each person's sports history.
• No range is forced to even out the sides in the same session.

Variations

Adaptations

• Limited mobility: compare sides on shoulder, wrist and trunk rotation tests from the wheelchair.
• Autism: gets the four tests on numbered cards and always works with the same partner.
• Overweight: hip internal rotation is measured sitting on a high bench, and balance is done with one hand on the wall.

Learning goals

• Calculate and interpret asymmetry percentages in mobility tests.
• Connect asymmetries with habits and sports played.
• Select specific exercises for the more limited side.

Equipment for a class of 25

• tablets or phones: 14
• tape measures: 7
• exercise mats: 14
• stopwatches: 7
• worksheets: 28

Teacher tip

Many one-sided athletes (tennis, team handball) will show expected shoulder differences; use it to talk about adaptation versus risk.

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