# STUDY 000A MICROSTUDY A

This folder contains the first supportive microstudy for `Study 000A`.

## Why this study exists

This study was conducted after completion of `Study 000A`. The flagship study showed that later adaptation occurred inside a treadmill-dominant specialization phase. This package asks whether that shift toward lower stabilization-demand context was itself part of the adaptation strategy.

## How this fits the archive

`Study 000A` is the primary synthesis.

This package is a supporting investigation that:

- follows the flagship rather than competes with it
- tests one explanatory factor that emerged from the flagship interpretation
- treats treadmill-versus-outdoor as the current proxy for stabilization-demand differences
- refines the main findings without replacing them

## Headline findings

- The packaged QC-pass set contains 179 treadmill runs versus 8 outdoor runs.
- The two longest outdoor anchors occur on April 16, 2025 and April 9, 2026.
- In the later outdoor anchor, stride length is 13.4% below treadmill-neighborhood mean while vertical ratio is 8.5% above it.
- These patterns support the interpretation that lower stabilization-demand context carried adaptive meaning rather than serving only as a methodological caveat.

## Main outputs

- `manuscript/STUDY000A_MICRO_A_MANUSCRIPT.md`
- `reports/STUDY000A_MICRO_A_ABSTRACT.md`
- `reports/STUDY000A_MICRO_A_METHODS.md`
- `reports/STUDY000A_MICRO_A_RESULTS.md`
- `reports/STUDY000A_MICRO_A_DISCUSSION.md`
- `reports/STUDY000A_MICRO_A_LIMITATIONS.md`
- `reports/STUDY000A_MICRO_A_PLAIN_LANGUAGE_SUMMARY.md`
- `reports/STUDY000A_MICRO_A_SUBMISSION_GUIDANCE.md`
- `reports/STUDY000A_MICRO_A_AUDIT.md`
- `appendices/APPENDIX_A_PACKAGED_SOURCES.md`
- `figures/`
- `outputs/`
- `source_tables/`