Measurement of Jumping Ability [.pdf]
Olson (1987) stated "A maximal effort standing vertical jump is a common physical fitness test used to indicate explosive power capability, as opposed to a test like the 12-minute run, which is used to measure endurance and cardiovascular fitness." (p. 36).
In 1921, a valid measurement tool was developed to measure leg power. Sargent and McCoy were the founders of this test (Olson, 1987). Subjects jumped as high as possible toward a cardboard box suspended above their head. A two-arm swing was used in preparation for the jump. At peak height, the arms were swung back to the subject's side. The distance between standing height and height of the box where the head touched was called the jump height. Jump height and weight were entered into an efficiency book to determine subject rating, or power output (Olson, 1987).
A more recent version of the jump has the athlete stand facing a smooth, dark wall with both feet flat on the floor and toes touching the wall. Subject's reach as high as possible with either hand and mark on the wall with a piece of chalk or chalk dust. Holding the desired jump position with the preferred side to the wall, the subject jumps as high as possible and makes another mark at the peak of the jump. The vertical jump score is the difference between the two marks (Klavora, 2000).
Abalakov's test was developed in 1938. He introduced a practical method to measure vertical jump with arm movement height using a metric tape attached to the waist of the subject and the ground (Bosco, 1999).
The Vertec is another tool in which vertical jump height can be measured. Perrine, a biomechanical research consultant (human performance and training specialist) developed and tested the instrument. Constructed with 49 colored plastic swivel vanes arranged in half-inch increments attached to a telescopic metal pole that can be adjusted to an athletes standing reach of up to 12 feet (Klavora, 2000).
As the athlete jumps and contacts the target area, the vanes that have been touched move while the others stay in place. The plastic vanes on the instrument provide a clear reading of the athletes jump height without the guesswork of a yardstick (Villareal, 1992). Beal (1988) stated that "the design of the Vertec allows the athlete to stand underneath the device. Perrine indicated that by standing underneath the Vertec all of the momentum can be directed vertically, therefore, no power is lost in the horizontal plane" (p. 56). The concentration is now better because the athletes do not have to worry about hitting the wall and they can concentrate on jumping straight up and achieving their best performance. The Vertec also aids the athlete because it gives them a visual cue. Seeing the vanes may help them motivationally to hit the next vane. Beal (1988) suggested that "the Vertec allows for true optimal jump testing efforts, and is a quality instrument that has demonstrated durability in programs all over the country" (p. 57). Aragon-Vargas (2000), conducted a study evaluating the reliability, validity, and accuracy of 4 different methods commonly used to measure vertical jump performance. The study comprised of 52 active men that each performed 5 maximal vertical jumps. The methods were a criterion test based on the body center of mass displacement or the vertical jump performance test, 2 methods based on vertical takeoff velocity as calculated from the force platform, and 1 method based on time in the air. The vertical jump performance test involves calculating the exact position of the body center of mass over time, using cinematography or video techniques.
Aragon-Vargas (2000) stated that "Jump height is obtained by subtracting the position of the body center of mass when the participant is standing, from the peak body center of mass during flight" (p. 216). This method involves mechanically correct concepts and the equipment is calibrated precisely the vertical jump performance test is considered the standard method to evaluate vertical jump. The researcher showed that the validity coefficient was r = .95 and the reliability coefficient was r = .97. The other three methods showed similar results but with poor accuracy. The vertical jump test is the most accurate, reliable, and valid test (Argon-Vargas, 2000).