TIP Model — Tube Internal Pressure Model

A new biomechanical framework for understanding human explosive movement through intramuscular pressure generation and geometric force transmission.

Overview

The TIP (Tube Internal Pressure) Model proposes that intramuscular compartment pressure serves as a primary mechanical support mechanism in human movement, operating alongside skeletal and muscular force transmission. This framework challenges the conventional joint-torque summation model and resolves the well-known SSC (Stretch-Shortening Cycle) energy gap.

Key Concepts

Mutual Eccentric Contraction Loop

The hamstrings and gastrocnemius form a mutual elongation loop during simultaneous contraction in closed-chain movement, maximizing intramuscular pressure in both muscles via multi-layer spiral fascial architecture.

Extensor Latch Mechanism (Champagne Cork Model)

Extensor muscles at the ankle and lumbar region act as seals (latches) that maintain accumulated pressure. Their active contraction withdraws the latch, triggering explosive pressure discharge — analogous to pulling a champagne cork.

Active Hydraulic System

Human takeoff is reframed as an active hydraulic system with three functional components:

• Pump: Mutual eccentric contraction generates intramuscular pressure
• • Seal: Extensor latch maintains accumulated pressure
  • • Valve: Active latch withdrawal controls explosive discharge

    • Publications

    • | Title | Date | DOI |
    • |-------|------|-----|
    • | Coupling of Pressure Generation and Geometric Transmission: Revised Model | March 2026 | 10.5281/zenodo.19227329 |
    • | Coupling of Pressure Generation and Geometric Transmission (Original) | Feb 2026 | 10.5281/zenodo.18693975 |
    • | Rigid-Body Mechanical Analysis of Hamstring-Driven Knee Extension | March 2026 | 10.5281/zenodo.19032888 |
    • | Self-Pressurizing Hydrostatic Actuator Based on Bio-Inspired Fascial Architecture | Feb 2026 | 10.5281/zenodo.18681135 |
    • | TIP Model Vol. 1.08: Universal Physical Principles of Jumping | Dec 2025 | 10.5281/zenodo.18105606 |
    • See all publications on Zenodo.

    • Author

    • Seiji Sato
    • Independent Researcher / Medica Sato Co., Ltd.

    • License

    • This project is licensed under the CC0 1.0 Universal License - see the LICENSE file for details.

    • Citation

    • If you use this work, please cite:

    • Sato, S. (2026). Coupling of Pressure Generation and Geometric Transmission:
      Revised Model Incorporating Mutual Eccentric Contraction and Extensor Latch Mechanism.
      Zenodo. https://doi.org/10.5281/zenodo.19227329
      ```# TIP-Model
      

TIP Model: Biomechanical framework for human explosie movement via intramuscular pressure and geometric orce transmission