Countermovement jump

In a countermovement jump, the athlete drops into a quick partial squat, flexing the hips and knees and swinging the arms back, then jumps as high as possible.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 242.} Jumping from a held partial squat with no dip is called a squat jump.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 242.}

The dip stretches the leg muscles just before they shorten, using the stretch-shortening cycle.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 488.} Most powerful movements involve this kind of countermovement.^{3Hoffman, NSCA’s Guide to Program Design, p. 117.} The time from the start of the countermovement to takeoff is often under 0.4 seconds.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 107.}

The dip adds height. Of three common jumps, the static squat jump is lowest, the countermovement jump sits in the middle and the approach jump with a run-up is highest.^{5Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 489.}

In practice

• ACSM calls countermovement jump height a common stand-in for muscular power in younger people, where impact loading is less of a concern.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 246.}
• ACSM publishes norms for jump height in centimeters by age and sex.^{7Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 248.}
• Jump height can be measured with a contact mat or a force plate.^{8Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 285.}
• The NSCA’s vertical jump test uses a countermovement jump.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 242.}
• Low-intensity plyometric drills that include countermovement jumps can be done safely without first meeting a strength requirement.^{9Hoffman, NSCA’s Guide to Program Design, p. 118.}