In reality, biomechanical systems such as the human-body, mammal, and birds physically collide or interact with environment. Intelligent mobility inherent in biomechanical systems plays the role of absorbing the impulse that happens due to collision with environment. The impulse transmitted to the lowerextremity of biomechanical systems is first distributed to multiple contact points of foot. Subsequently, jointed leg structure absorbs the impulse as the form of momentum. Thus, the proximal joints far from the contact points receive less amount of impulse. This fact has been understood in an intuitive manner without any analytical ground. This work proposes a Newton-Euler based closed-form impulse model for biomechanical systems in case of multiple contacts. This model is applied to analyze the characteristic of the intelligent mobility of biomechanical system through an example of a landing Ostrich’s leg. Furthermore, potential application of the impulse model for multi-chained linkage systems is addressed.