Purpose:
Tests such as the counter movement jump (CMJ) and squat jump (SJ) allow for determining the ratio of maximal power output generated during SJ to CMJ (S/C). The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q) is defined as functional H/Q. The purpose of this study was to compare the S/C and functional H/Q between female basketball and volleyball players.

Methods:
The total of 14 female basketball players (age, 19.8 ± 1.4 years) and 12 female volleyball players (age, 22.3 ± 4.2 years) participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed.

Results:
The results of the S/C and functional H/Q at 90 deg • s^–1/60 deg • s^–1 velocities were higher in basketball players (87.3 ± 9.1% and 91.4 ± 9.3%, respectively) than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively). No significant differences in S/C or functional H/Q values between the two groups were found (p > 0.05).

Conclusions:
Decreasing the S/C may result from an improvement in the power output during CMJ and a better utilization of the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can provide dynamic knee joint stabilization.