Integrating Threshold-Guided Progressive Stretching with Passive Moiré Visual Biofeedback in High-Flexibility Sports: A Conceptual Framework and Pilot Evidence
DOI:
https://doi.org/10.47363/JSPM/2026(2)109Keywords:
Hamstring Strain Injury, Kinesio Phobia, Stretching, Biofeedback, Moiré Gymnastics, Rehabilitation, Return to SportAbstract
Objective: To substantiate the feasibility of integrating Threshold-Guided Progressive Stretching (TGPS) supported by an objective visual Moiré strain indicator into high-flexibility sport practice as a field-ready approach to reduce Kinesio phobia and mitigate hamstring strain injury (HSI) risk.
Methods: A prospective single-group 8-week pilot with pre-post assessment (n=23 women; 28.4±5.2 years) was conducted in a high-mobility training model. Participants used an elastic band printed with a micro-pattern that produces a Moiré “LIMIT” marker at an individualized strain threshold (approximately 75–85% of range of motion [ROM]). Core stretches (forward fold, straddle, and related patterns) were performed at the threshold zone for 8–12 s, 3–5 repetitions, 20–35 min/day. Outcomes included feasibility (adherence), safety (overstretch events), ROM (goniometry), kinesio phobia (TSK-11), and perceived confidence/control (visual analogue scales). Statistics used paired t-tests and Cohen’s d.
Results: Feasibility was high (92% adherence) with 0 overstretch events across 240 person-hours of controlled stretching. ROM improved by 12.4° (95% CI 10.1–14.7; p<0.001), split depth improved by 4.2 cm (p<0.001), TSK-11 decreased by 11.4 points (p<0.001), and perceived confidence/control increased by 26.3 mm (p<0.001).
Expectancy showed negligible correlation with ROM change (r=0.08).
Conclusions: TGPS supported by a passive Moiré visual indicator may standardize threshold stretching, reduce fear-avoidance responses, and enhance perceived safety in disciplines requiring end-range mobility. Randomized controlled trials with sham control and elite gymnast samples are warranted. Practical implementation is compatible with daily warm-up/cool-down routines and post-HSI rehabilitation, especially when combined with breathing cues and brief journaling to reinforce self-efficacy.