###### Abstract  
In performance testing, it is well-established that general jump types like squat and countermovement jumps have great reliability, but the relationship with volleyball spike jumps is unclear. The objectives of this study were to analyze the relationship between general and spike jumps and to provide improved models for predicting spike jump height by general jump performance. Thirty female and male elite volleyball players performed general and spike jumps in a randomized order. Two AMTI force plates (2000 Hz) and 13 Vicon MX cameras (250 Hz) captured kinematic and kinetic data. Correlation and stepwise-forward regression analyses were conducted at \(p<0.05\). Simple regression models with general jump height as the only predictor for spike jumps revealed \(0.52\leq R^{2}\leq 0.76\) for all general jumps in both sexes (\(p<0.05\)). Alternative models including rate of force development and impulse improved predictions during squat jumps from \(R^{2}=0.76\) to \(R^{2}=0.92\) (\(p<0.05\)) in females and from \(R^{2}=0.61\) to \(R^{2}=0.71\) (\(p<0.05\)) in males, and during countermovement jumps with arm swing from \(R^{2}=0.52\) to \(R^{2}=0.78\) (\(p<0.01\)) in males. The findings include improved prediction models for spike jump height based on general jump performance. The derived formulas can be applied in general jump testing to improve the assessment of sport-specific spike jump performance. kinematic; kinetic; 3D analyses; influence; prediction; regression models; advanced performance testing; squat jump; countermovement jump +
Footnote †: journal: Applied Sciences  
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Footnote 1: [[https://doi.org/10.3390/app11031105](https://doi.org/10.3390/app11031105)]([https://doi.org/10.3390/app11031105](https://doi.org/10.3390/app11031105))  
a foot-planting phase to transfer velocity from horizontal to vertical. Decreased knee and upper body incline angles allow for lowering the center of mass (CoM) and, thus, increasing the acceleration path before the take-off [6]. A dynamic arm swing supports an explosive push-off with both legs [7], which is expressed by great peaks in the rate of ground reaction force development (RFD). Due to its complexity, the VSJ requires technical and coordinative skills. Hence, VSJ performance is not only affected by strength and power but also by movement-specific, technical coordination skills [6]. The complexity of the VSJ movement can make standardized performance testing and training difficult. Therefore, less complex general jump types are commonly used for testing [8] and training [9]. The general jump types for these purposes include the squat jump (SJ), countermovement jump without arm swing (CMJ), and countermovement jump with arm swing (CMJ) [8]. Despite not being sport-specific, these jump types are frequently used in testing and training to assess and improve jump performance in volleyball players [8,9]. This is due to the practical advantages of standardized general jumps, which are easier to be implemented and interpreted due to great reliability and factorial validity of these jumps [10]. However, it is unclear how suitable these general jump types are for the assessment of the sport-specific jump performance during VSJ. Clearly, though, each general jump type incorporates different aspects that have been described as characteristics for the VSJ performance: Generating great power and RFD during the SJ [11], involving a stretch-shortening-cycle during the CMJ, and supporting an explosive push-off when adding the arm swing during the CMJ. Therefore, the various general jump types may not fully capture the determinants of success in VSJ requiring additional considerations to assess VSJ performance based on various general jumps. Such differentiated considerations would allow the practical usage of general jump tests with greater reliability while advancing the explanatory power of the results that relate to VSJ performance.