Sequence-Dependent Performance Adaptations Following Myofascial Chain Training in Youth Football Players

Sequence-Dependent Performance Adaptations Following Myofascial Chain Training in Youth Football Players: An Integrated Statistical and Knowledge Graph Approach

This study looked at whether the order of two different types of muscle-and-connective-tissue ("myofascial chain") training affects how young football players improve their jumping power and balance.

Forty male football players, aged 15 to 16, took part. Players were split into two groups by chance. One group did "posterior chain" training first, then switched to "spiral chain" training. The other group did the trainings in the opposite order. Each training phase lasted six weeks, and players kept doing their normal team practice at the same time.

Jumping power and balance were measured four times: before training started, after the first six weeks, after the second six weeks, and again four weeks after training ended.

The goal was to find out if starting with one type of training instead of the other leads to bigger, faster, or longer-lasting improvements. This information may help coaches design better training programs for young athletes.

Study Overview

• Status: Completed
• Conditions: Athletic Performance in Adolescent Athletes
• Intervention / Treatment: Other: Posterior chain myofascial training; Other: Spiral chain myofascial training

Detailed Description

Myofascial chains are interconnected lines of muscle and connective tissue (fascia) that transmit force across body segments and contribute to movement efficiency, joint stability, and elastic energy storage. Among the chains described in fascial anatomy literature, the posterior chain is considered a primary contributor to explosive force production, while the spiral chain contributes to rotational control and balance. Despite growing interest in fascia-informed training, no prior study has examined whether the sequence in which these chains are trained influences the magnitude, time-course, or persistence of performance adaptations in youth athletes.

This study used a randomized crossover design to compare two training sequences in licensed U15-U16 male football players who were actively training and competing with their clubs. Participants were randomly allocated in a 1:1 ratio to one of two sequence groups: the Posterior Chain First Group (PCFG) and the Spiral Chain First Group (SCFG). Both groups continued their regular club training throughout the study.

The intervention consisted of two consecutive six-week training blocks. During the first block, the PCFG performed a posterior chain-focused myofascial training protocol while the SCFG performed a spiral chain-focused protocol. After mid-test assessments, the groups crossed over: the PCFG then performed the spiral chain protocol and the SCFG performed the posterior chain protocol for the second six-week block. Each training session lasted 30 minutes (6-minute warm-up, 20-minute main phase with five functional exercises, 4-minute cool-down) and was completed in addition to routine club training.

Outcomes were assessed at four time points: pre-test (baseline), mid-test (after the first six-week block), post-test (after the second six-week block), and follow-up (four weeks after the post-test, to assess the persistence of adaptations). The primary outcome was lower-limb explosive power, measured using the countermovement jump (CMJ) recorded with a photocell device. The secondary outcome was dynamic balance, measured using the Y-Balance Test (YBT) for both the right and left stance legs (YBT-R, YBT-L), with reach distances normalized to leg length.

Data were analyzed using a 2 (group) x 4 (time) mixed-design ANOVA for each outcome, with Greenhouse-Geisser correction applied where sphericity was violated and Bonferroni-adjusted pairwise comparisons used to identify the specific time points driving significant time effects. A separate mixed-design ANOVA, using phase-specific gain scores as the within-subject factor and sequence group as the between-subject factor, was used to formally test for carryover (sequence) effects. In addition to conventional statistical analysis, the dataset was modeled as a knowledge graph (Neo4j graph database) to explore phase-dependent adaptation trajectories and inter-individual response patterns that are not readily captured by conventional repeated-measures analysis. This graph-based analysis was exploratory and supplementary to the primary statistical analysis.

This trial is being registered retrospectively, after completion of data collection and analysis.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Mersin
    • Mersin, Mersin, Turkey (Türkiye), 33343
      • Mersin University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

IInclusion Criteria:

• Male, aged 15-16 years (U15-U16 category)
• Holding an active football player license and currently competing with a club team
• Regularly participating in routine club training sessions
• Free from any injury or musculoskeletal condition that could affect performance testing at the time of enrollment
• Parental/legal guardian consent and participant assent obtained

Exclusion Criteria:

• Presence of any musculoskeletal injury, recent surgery, or medical condition affecting lower-limb function within the past 6 months
• Inability to attend the required training sessions or assessment time points
• Unwillingness or inability of parents/legal guardians to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PCFG (Posterior Chain First); Participants performed a posterior chain-focused myofascial training protocol during the first 6-week period, followed by a spiral chain-focused protocol during the second 6-week period, in addition to routine club training.	Other: Posterior chain myofascial training; A 6-week, twice-weekly structured training protocol targeting the posterior myofascial chain, consisting of a warm-up, five functional exercises, and a cool-down phase, delivered in addition to routine club training.; Other: Spiral chain myofascial training; A 6-week, twice-weekly structured training protocol targeting the spiral myofascial chain, consisting of a warm-up, five functional exercises, and a cool-down phase, delivered in addition to routine club training.
Experimental: SCFG (Spiral Chain First); Participants performed a spiral chain-focused myofascial training protocol during the first 6-week period, followed by a posterior chain-focused protocol during the second 6-week period, in addition to routine club training.	Other: Posterior chain myofascial training; A 6-week, twice-weekly structured training protocol targeting the posterior myofascial chain, consisting of a warm-up, five functional exercises, and a cool-down phase, delivered in addition to routine club training.; Other: Spiral chain myofascial training; A 6-week, twice-weekly structured training protocol targeting the spiral myofascial chain, consisting of a warm-up, five functional exercises, and a cool-down phase, delivered in addition to routine club training.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Countermovement Jump (CMJ) Height	Lower-limb explosive power was assessed using the countermovement jump, measured with a photocell device (SE-JP1). Each participant performed three non-consecutive jumps with hands on hips, and the mean of the three trials was used for analysis.	Measured at baseline (pre-test), after 6 weeks (mid-test), after 12 weeks (post-test), and 4 weeks after the post-test (follow-up)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dynamic Balance - YBT	Dynamic balance was assessed using the Y-Balance Test with the right/left leg as the stance leg, measuring reach distance (cm) in the anterior, posteromedial, and posterolateral directions, normalized to leg length.	Measured at baseline (pre-test), after 6 weeks (mid-test), after 12 weeks (post-test), and 4 weeks after the post-test (follow-up)

Collaborators and Investigators

• Sponsor: Mersin University

Study record dates

Study Major Dates

• Study Start (Actual): May 5, 2025
• Primary Completion (Actual): September 1, 2025
• Study Completion (Actual): December 22, 2025

Study Registration Dates

• First Submitted: June 18, 2026
• First Submitted That Met QC Criteria: June 18, 2026
• First Posted (Actual): June 24, 2026

Study Record Updates

• Last Update Posted (Actual): June 24, 2026
• Last Update Submitted That Met QC Criteria: June 18, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: balance; countermovement jump; knowledge graph; Myofascial chain sequencing; posterior chain
• Other Study ID Numbers: MEU-SBF-IK-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data underlying the results reported in this article (CMJ and Y-Balance Test scores at all four assessment time points), along with the study protocol.
• IPD Sharing Time Frame: Beginning 3 months and ending 5 years after article publication
• IPD Sharing Access Criteria: Investigators who provide a methodologically sound proposal, for use in achieving the aims of the approved proposal. Requests should be directed to the corresponding author.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No