The countermovement jump (CMJ) is a simple, practical, valid, and very reliable measure of lower-body power. As a consequence, it is no surprise that this has become a cornerstone test for many strength and conditioning coaches and sports scientists. The CMJ has been shown to be the most reliable measure of lower-body power compared to other jump tests. Furthermore, the CMJ has been shown to have relationships with sprint performances, 1RM maximal strength, and explosive-strength tests.
This suggests that performances in the CMJ are linked with maximal speed, maximal strength, and explosive-strength. When the CMJ is performed using the arm-swing, performances can be ≥10% higher than when they include no arm-swing. Contact mats, force platforms, accelerometers, high-speed cameras, and infrared platforms have all been shown to provide a valid and reliable measure of CMJ performance – though force platforms are considered as the ‘gold-standard’.
This test is not to be confused with the Abalakow Jump test, or any of the Jump-and-Reach tests such as: the Sargent Jump test, the Vertical Power Jump, or the Vertical Jump test (i.e. Vertec) (1).
Keywords: power, vertical jump, CMJ, arm-swing