Lec 7 Segmented Systems Flashcards
What is Degrees of Freedom?
Number of parameters necessary to describe the state of a system
What are (3) torques in joint movement?
1) Isometric Contraction
2) Concentric Contraction
3) Eccentric Contraction
Further the force of the resistant is the ______ in increased?
Joint
What are the (3) cause movements in a Net Torque?
1) Muscle Torque
2) Interaction Torque
3) Gravitational Torque
What causes the Muscle Torque (MT)?
All muscles acting at a joint
What causes Interaction Torque (IT)?
Other segments acting on a joint
What is Gravitational Torque?
Gravity
What = Net Torque?
MT (Muscle Torque) + IT (Interaction Torque + GT (Gravitational Torque)
What are uses for Interaction Torques?
Moving a joint a certain way
Provide damping/stiffness, or decelerate a segments
Oppose movements caused by Interaction Torque
What was the main idea of Leading Joint Hypothesis?
the CNS exploits the biomechanical properties of the limbs for movement organization.
What do Multi-Joint systems consist of?
Leading joint and a subordinate joint
What are (3) problems of Multi-Joint Movements?
1) Redundancy of degrees of freedom
2) there are many different movement trajectories to use to do the same thing.
3) Limb dynamics make things complicated
When moving, you should treat your leading joint as a single joint and it is the simplest to control. What is the advantage of being a leading joint?
mechanical advantage
In a leading joint, what causes reciprocal muscle activity?
Acceleration and Deceleration
What causes motor Interaction torque for subordinate joints?
Motion of leading joint, resulting in appropriate limb movement for task
