Can the vertical jump height measure the lower limbs muscle strength?

The vertical jump is frequently used for the functional evaluation of athletes and non-sporting subjects. The jump height is often used as an indicator of lower limbs strength. The aim of this study was to verify the presence of a relationship between the maximum height reached and muscle parameters expressed during the vertical jump. In 22 healthy males practicing recreational physical activity (age, mean ± standard deviation: 22.5±1.2 years; body mass: 72.8±13.2 kg; body height: 177.1±7.0 cm) and in 15 female volley players (age: 16.5±0.4 years; body mass: 64.4± 8.4 kg; body height: 175.5±7.9 cm), Jump Height (cm), Muscle Strength (N/kg) and Power (W/kg) were recorded during the jump tests. In the healthy males group, jump height was correlated with muscle power: r = 0.33, p>0.05; a higher correlation resulted between muscle strength and power: r = 0.62, p<0.01. In the female volleyball players group, only the muscle strength and power showed a correlation: r = 0.54, p<0.05. It is therefore possible to confirm that the jump height reached during a vertical jump does not provide clear information on the strength of the lower limbs. At the same time, an improvement in muscular strength of the lower limbs does not guarantee an increase in jump height. Several parameters should be evaluated at the same time for a correct functional assessment of athletes and healthy non-sporting subjects.