The Dynamic Diagonal Model (DDM) proposes a distinct, trainable coordination regime characterized by diagonal myofascial integration and enhanced efficiency. A central paradox emerges: practitioners report profound, qualitative shifts in movement experience, yet initial experimental protocols predict quantitative effects (e.g., ≥5% VO₂ reduction) that may be challenging to detect after brief training. This theoretical paper resolves this paradox by introducing the Femoral-Spinal-Thoracic Integration Hypothesis. We propose that DDM's primary mechanism is not the visible diagonal pattern itself, but a deeper three-spiral synchronization (femoral generator, pelvic integrator, foot stabilizer) that transforms vertical forces into helical transmission via the T12-L1 junction. The subjective "depth" corresponds to engagement of this deep, mechanically efficient coordination, while conventional biomechanical tools capture its surface manifestations. Crucially, we introduce the Rotational Moment Stabilization Hypothesis, positing that the full biomechanical and metabolic benefits of DDM emerge across three phases (Discovery, Consolidation, Fixation) requiring weeks of practice. This framework generates six novel, testable predictions, including femoral micro-rotation signatures and dose-dependent metabolic improvements. We conclude that early, null, or partial experimental findings do not falsify DDM but may reflect a mismatch between measurement tools and the depth of the proposed mechanism. This reconceptualization transforms DDM from a hypothesis about a movement pattern into a research program on deep coordination learning, with implications for rehabilitation, sports science, and the study of expertise.
Vasiliev, Roman (Wed,) studied this question.