ArticleFrontiers in bioengineering and biotechnology2026
Field-to-laboratory biomechanical profiling of reactive strength index in male volleyball drop jumps.
Article in Frontiers in bioengineering and biotechnology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Background: Reactive strength index (RSI) is widely used in drop-jump testing, but the score alone does not show how the landing-to-take-off phase is organized. Objective: This study examined whether RSI in male volleyball drop jumps can be interpreted more clearly by combining field-accessible performance metrics with time-continuous knee-joint biomechanical waveforms. Methods: Forty-four male volleyball participants were classified as trained athletes (n = 22) or recreational participants (n = 22). Each completed 30-cm drop jumps using force platforms and three-dimensional motion capture. Field outcomes included jump height, contact time, RSI, and countermovement depth. Laboratory outcomes included dominant-limb knee angle, moment, and power waveforms, with supplementary lower-limb peak joint and work-distribution outcomes. Discrete outcomes were analyzed with mixed models and covariate-adjusted models; waveforms were compared in Python using one-dimensional statistical parametric mapping, with supplementary body mass-normalized kinetic waveform analyses. Results: Compared with recreational participants, trained athletes had shorter contact time (adjusted β = -0.093 s, 95% CI: -0.157 to -0.030), smaller countermovement depth (adjusted β = -7.03 cm, 95% CI: -11.98 to -2.08), and higher RSI (adjusted β = 0.273 m/s, 95% CI: 0.131-0.415). Knee propulsive work was higher before anthropometric adjustment, whereas the adjusted result was statistically inconclusive. Waveform analysis showed less knee flexion across most of contact, greater knee moment during middle-to-late contact, and phase-specific knee-power differences. Conclusion: Higher RSI in trained male volleyball athletes was associated with a compact field-level landing-rebound pattern, defined by shorter contact time and smaller countermovement depth, supported by lower-limb discrete outcomes and knee-joint waveform features rather than a single biomechanical feature. Combining field-accessible metrics with lower-limb biomechanical analysis may provide a more interpretable profile of reactive strength in volleyball drop jumps.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.