Myofascial chain sequencing and performance adaptations in youth football players: an exploratory knowledge...

This study investigated the effects of myofascial chain-focused training on countermovement jump (CMJ) performance and dynamic balance in a small, specific cohort of youth football players, while also examining how performance changed across the intervention with different chain sequences.

Forty licensed adolescent male football players (U15-U16) participated in a 12-week intervention program consisting of training protocols based on distinct myofascial chain sequences (posterior-chain-first vs. spiral-chain-first). Performance assessments were conducted at four time points (pre-test, mid-test, post-test, and follow-up) using the CMJ and Y-Balance Test (YBT). The resulting data were analyzed through both conventional statistical approaches and a knowledge graph-based framework designed to model phase-dependent adaptation dynamics.

ANOVA revealed a significant main effect of time for all variables (CMJ: F₁.₅₁₅,₅₇.₅₈₁ = 69.15, p < .001, ηp² = 0.645; YBT-R: F₁.₀₃₃,₃₉.₂₆₈ = 17.12, p < .001, ηp² = 0.311; YBT-L: F₁.₀₅₂,₃₉.₉₇₂ = 11.45, p < .001, ηp² = 0.232). However, the Time × Group interaction was not significant for any variable (p > .05 for all), indicating similar overall improvement trajectories between sequences. Pairwise comparisons showed that CMJ improved progressively across all time points (pre-to-follow-up mean difference = 7.57 cm, p < .001). Descriptive knowledge graph queries showed numerically larger early-phase CMJ gains in the spiral-chain-first group (Pre-Mid mean delta = 3.65 cm vs. 2.80 cm) and numerically larger late-phase gains in the posterior-chain-first group (Post-Follow-up mean delta = 4.49 cm vs. 1.49 cm). These differences were exploratory and were not supported by an independent inferential test of sequence effects across phases.

Myofascial chain training was associated with improvements in CMJ and YBT performance over time, but no training sequence was demonstrated to be statistically superior. The knowledge graph provided a complementary relational representation of changes across intervention phases and individual athlete responses; however, these outputs were descriptive and hypothesis-generating rather than independent inferential evidence. Therefore, the observed numerical differences between sequences should not be interpreted as proof of sequence superiority. Due to the small and specific sample, these findings have limited generalizability, and the observed sequence-specific patterns remain exploratory and hypothesis-generating.

ClinicalTrials.gov NCT07665138, Registered 18/06/2026. Retrospectively registered.