Jumping With and Without Countermovement

In groups, students use a slow-motion video app to measure three types of vertical jump: squat jump, countermovement jump and countermovement jump with arm swing. From the results they calculate their elastic index and learn how to use elastic energy at takeoff.

How to play

1. Explain the three jumps and how to calculate height from flight time with the app (4 min).
2. Groups of four: jumper, filmer at floor level, recorder and technique checker (1 min).
3. Each student does two jumps of each type while their feet are filmed from the side (8 min).
4. The group calculates each jump height and the elastic index: countermovement jump minus squat jump, divided by the squat jump (4 min).
5. Group discussion: connect the index to takeoff in the high jump and long jump (3 min).

Rules

• Land on both feet, absorbing with the knees and never locking them.
• Hands stay on the hips in the first two jump types so the measurement is valid.
• Groups are at least 6 feet apart.
• Nobody jumps barefoot or on a wet floor.

Variations

Adaptations

• Limited mobility: measures a seated medicine ball throw with and without a trunk countermovement.
• Hearing impairment: the protocol is on a picture card and the countdown is done with fingers.
• Ankle injury: films and calculates the data for the whole group.

Learning goals

• Distinguish concentric strength from elastic-explosive strength.
• Measure vertical jump with a reliable digital tool.
• Connect the data to takeoff technique in track and field.

Equipment for a class of 25

• tablets or phones: 7
• worksheets: 28

Teacher tip

Free slow-motion apps that let you step frame by frame at 240 fps are enough. An index close to zero usually points to a takeoff that is too slow.

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