Macroscopic muscle model

Macroscopic muscle model represents passive and active muscle forces using a Hill-type formulation to simulate muscle dynamics in biomechanical studies.

Key Features:

• Hill-type formulation: Implements a Hill-type muscle model as the core algorithm for simulating muscle dynamics.
• Contractile Element: Incorporates force–length and force–velocity relationships for concentric and eccentric contractions to compute active force generation.
• Parallel Elastic Element: Models the passive elastic properties of muscle tissue that act in parallel with the contractile element.
• Series Elastic Element: Models elasticity in tendons and connective tissues in series with muscle fibers to affect force transmission.
• Serial Damping Element: Accounts for energy dissipation through damping mechanisms within the muscle–tendon unit.
• Eccentric force–velocity behavior: Represents the eccentric force–velocity relationship important for realistic eccentric contractions and joint motion.
• Implementation compatibility: Provides a computational implementation compatible with MATLAB and Simulink environments.

Scientific Applications:

• Biomechanics: Simulates muscle-generated forces and interactions between muscle and connective tissues for biomechanical analyses.
• Motor control: Enables study of active and passive muscle contributions to movement and control strategies involving concentric and eccentric contractions.
• Rehabilitation sciences: Supports investigation of muscle dynamics relevant to rehabilitation, injury mechanics, and therapeutic intervention design.
• Joint motion simulation: Facilitates simulation of human-like joint motions, exemplified by improved elbow-joint flexion modeling through eccentric contraction representation.

Methodology:

Computes passive and active muscle forces by integrating a Hill-type model composed of contractile, parallel elastic, series elastic, and serial damping elements, using force–length and force–velocity relationships that include eccentric behavior.