1. Changing Objectives of Optimization 유리 Movement Research Lab

2. Topics 1. Metabolic energy expenditure minimization(new) 2. Co-activation parametrization

3. Topics 1. Metabolic energy expenditure minimization(new) 2. Co-activation parametrization

4. Metabolic energy expenditure(old)

5. Coactivation for anterior tibialis / lateral gastrocnemius(old) Muscle actuationJoint torqueMetabolic energy Anterior Tibialis Lateral Gastrocnemius

6. Metabolic energy expenditure(new) E = Metabolic energy expenditure E = m i · a i m i = mass of i-th muscle a i = activation of i-th muscle

7. Coactivation for anterior tibialis / lateral gastrocnemius(old) Muscle actuationJoint torqueMetabolic energy Anterior Tibialis Lateral Gastrocnemius

8. Coactivation for anterior tibialis / lateral gastrocnemius(new) Muscle actuationJoint torqueMetabolic energy Anterior Tibialis Lateral Gastrocnemius

9. Energy consumption & Coactivation Muscle actuation < Metabolic energy < Joint torque 150cal/m < 170/m < 180cal/m

10. Topics 1. Metabolic energy expenditure minimization(new) 2. Co-activation parametrization

11. Co-activation parametrization 00.10.20.3…0.91.0 Joint torque Muscle activation

12. Co-activation parametrization Range of muscle activation 0 ≤ a ≤ 1 When a = 0, muscle is fully relaxed exerting no active force When a = 1, muscle is exerting its maximum force 0.1 0.2 …

13. Co-activation pair? How can we define muscle co-activation pairs? Ex)anterior tibialis & lateral gastrocnemius

14. THANK YOU FOR YOUR ATTENTION.