Completed notes of the course

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1 T echnologies for motor behaviour analysis and virtual modelling Software: VideoDIGIT → Mokka → OpenSIM We take real data and we put them inside a software that will load it into a model of the motion. At this point we can change parameters and study the motion. Why there’s the need to simulate real data? 1. Prevention of injures; 2. Prediction of rehabilitation/surgical treatment outcomes: functional surgical planning; 3. Design and a-priori evaluation prostheses; 4. Virtual/augmented reality; 5. Surgical exploration/simulation; 6. Optimization of human-machine interfaces design; 7. Entertainment. For us a human body will be a kinematic chain actuated by muscles (muscle-skeletal model). We will think at motion as sequence of joints configuration or a sequence of muscle configuration. Which and where are the references? They are on the body, usually head references or trunk references. COM: the weighted average of the COM of the pieces of our body. It is in the pelvis. It’s the point of application of the external forces. COG: in the Earth it’s the same of COM. COP: it’s the point at which the reaction forces are acting. Usually it’s on the plantar of the feet. If we don’t move the COP is the projection of COM on the ground. In a dynamic situation this is not true. We’re an elaborate kinematic chain. How many degrees of freedom we have in the arm? In the wrist we have 3 DOF, in the elbow 1 and the shoulder a lot. We sum the DOF of every joint. In the model we will consider a simpler model, so we can consider only 2 DOF for the wrist. 2 The Direct kinematic problem: every kinematic chain has a base point (shoulder) and an end effector (arm), given joints configuration find position and orientation of the end effector. The Inverse kinematic: given the goal (position of…