KIN 3309 1nd Edition Lecture 12 Outline of Last Lecture I. How to Solve Kinematics ProblemsII. Question 1III. Question 2IV. Question 3V. Question 4VI. Question 5VII. Question 6VIII. Question 7IX. Question 8X. Question 9XI. Question 10XII. Question 11Outline of Current Lecture I. Kinetics and Kinematics – a RecapII. Force Plates/Ground Reaction ForcesIII. Force Plates/Ground Reaction Forces DevicesIV. Force Plates/Ground Reaction Forces Data CollectionV. Postural ControlVI. Force Plates/Ground Reaction Forces – ProblemsVII. Motion CaptureVIII. Motion Capture – Stroke Survivors ReachingCurrent LectureI. Kinetics and Kinematics – a Recapa. Kineticsi. To study the forces and interactions that affect motion, one must collect data that can relate to… Force = mass * accelerationb. Kinematicsi. To study bodies in motion, regardless of the causes of motion, one needs to describe and quantify linear and angular positions of bodiesc. Motion CaptureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. You can get kinematic information like joint positioning during certain movementsd. EMG & Goniometryi. EMG – the electrical activity of a muscleii. Goniometry – specifically measures joint anglese. Dynamometryi. Measuring work – you can do all three kinds of loads on a muscle: isometric, isokinetic, and isotonic.ii. Ex. bio dexf. Force Plates/ GRFsi. GRF – the ground pushes back against youII. Force Plates/Ground Reaction Forcesa. GRF i. Any force exerted by the ground on a body in contact with itii. One’s weight is a force that a person’s body exerts on the ground and, when not moving, the ground exerts an equal and opposite GRF on the person’s feetiii. Newton’s 3rd Law (Action/reaction)III. Force Plates/Ground Reaction Forces Devicesa. NeuroComi. We have people stand and see how they respond with different simulations to test balance. We can eliminate or mess with the systems that control balance.b. Berteci. Each foot is drivin independently on its own belt on the tredmill. You can have one foot move faster than the other. With this, its easy to adapt to. This is good for walking studies.c. AMTId. Other Manufacturerers:i. Kistlerii. Biodexiii. BTSiv. OthersIV. Force Plates/Ground Reaction Forces Data Collectiona. Force Platei. Measurement of GRFs, center of pressure, etc.b. Postural Control Researchi. COP in unperturbed stanceii. COP in perturbed stanceV. Postural Controla. Peak-to-peak sway – Anteroposterior (AP)b. Peak-to-peak sway – Mediolateral (ML)c. There’s a dead zone in the middle of the feet. If you get out of the dead zone, you have less stability. If you’re in the red zone a lot, you are an unstable person.VI. Force Plates/Ground Reaction Forces – Problemsa. Counter movement jumpb. Based on GRFz: What is the jumpers mass in kg? i. 1 N = 0.101 kg ii. So m = ~ 65 kgc. Where is the take-off, landing and what is the flight time? i. t = 0.6 sd. Based on the flight time calculate the jump height in meters! i. Use z = (g*t2)/8ii. z= .44 mVII. Motion Capturea. Eadweard Muybridgei. Muybridge was the first to do motion capture with animals to see if a horse was on its four feet or not during a gallop.b. Description of position (2D, 3D)i. Cartesian coordinate system (x,y,z)ii. Defined by origin and 2 or 3 orthogonal axesiii. Global Coordinate System (GCS)c. Description of the objecti. Points on/in objectii. Local Coordinate System (LCS)iii. Placed in segmental proximal joint or COMd. Passive Motion Capturei. Uses ambient or IR lightii. Captures video of reflective markers affixed to bodyiii. The light comes from the markers, the foam balls with reflective tapee. Active Motion Capturei. Uses LEDs or IR emitting markersii. The marker, the ball, is what is emmiting the signalf. Triangulation of Markers in GCS/LCSi. Identification of marker position in 2D/3D spaceg. Photogrammetryi. Frame rate (frequency in Hz), field of view (GCS(x,y,z))VIII. Motion Capture – Stroke Survivors Reachinga. Right arm is blue and left arm is redb. Even the persons non-stroke side is still affected by the