ABSTRACT

The aim of this investigation was to assess the reliability and validity of the Fitjump system. Fifty-seven participants (age = 22.62 ± 5.24 years, height = 180.69 ± 12.53 cm, body mass = 75.61 ± 9.56 kg) performed three countermovement jump (CMJ) and squat jump (SJ) with a 1-week interval for test and retest reliability. For validity, the participants performed the same jump protocol on the force platform while being simultaneously measured with the Fitjump system. There was excellent test–retest reliability of the Fitjump system for CMJ and SJ with high intraclass correlation coefficient (ICCs) (0.97 and 0.97, respectively), low coefficient variation (CVs) (2.3% and 2.4%, respectively), and low typical error of estimate [(TEE (%)] (4.0% and 4.4%, respectively). For validity, ICCs were extremely high for CMJ and SJ (0.93 and 0.94, respectively), with low TEE (%) (2.9% and 2.0%, respectively). However, Fitjump overestimated jump height for CMJ and SJ (3.54 and 3.37 cm, respectively; p < 0.001) when compared with the force platform. As a conclusion, the Fitjump system demonstrated excellent test–retest reliability and high relationship with a systematic bias for validity. Therefore, the Fitjump system can be used as a portable tool for monitoring vertical jump changes over time, but it should not be used interchangeably with a force platform.

摘要

这项研究的目的是评估Fitjump系统的可靠性和有效性。五十七名参与者（年龄= 22.62±5.24岁，身高= 180.69±12.53 cm，体重= 75.61±9.56 kg）进行了三个反向运动跳跃（CMJ）和深蹲跳跃（SJ），每隔1周进行一次测试和重新测试可靠性。为了确保有效性，参与者在用力平台上执行了相同的跳跃协议，同时使用Fitjump系统进行了同时测量。Fitjump系统对CMJ和SJ具有出色的重测可靠性，具有较高的组内相关系数（ICC）（分别为0.97和0.97），低系数变化（CV）（分别为2.3％和2.4％）和低典型值估计误差[（TEE（％）]（分别为4.0％和4.4％）。出于有效性考虑，CMJ和SJ的ICC极高（分别为0.93和0.94），TEE（％）低（分别为2.9％和2.0％）。但是，Fitjump高估了CMJ和SJ的跳跃高度（分别为3.54和3.37厘米；与受力平台相比，p <0.001）。结论是，Fitjump系统表现出出色的重测信度和高度可靠性，并存在系统性的有效性偏倚。因此，Fitjump系统可用作监视垂直跳动随时间变化的便携式工具，但不应与测力平台互换使用。