Basic Kinematics

Course Content I.Introduction to the Course II.Biomechanical Concepts Related to Human Movement III.Anatomical Concepts Related to Human Movement IV.Applications in Human Movement

Course Content I.Introduction to the Course II.Biomechanical Concepts Related to Human Movement III.Anatomical Concepts Related to Human Movement IV.Applications in Human Movement

Biomechanical Concepts A.Basic Kinematic Concepts B.Vector Algebra C.Basic Kinetic Concepts

Biomechanical Concepts A.Basic Kinematic Concepts B.Vector Algebra C.Basic Kinetic Concepts

Basic Kinematic Concepts 1.Variables for Describing Motion 2.Reference Systems for Describing Motion of the Human Body and Its Segments 3.Guidelines for Describing Motion of the Human Body and Its Segments

Rigid Body Mechanics Rigid Body Mechanics Statics Constant Velocity KinematicsKinetics Motionless Dynamics KinematicsKinetics

What is kinematics? Spatial and temporal characteristics Qualitative or quantitative Linear & angular motion

Why use kinematics? Practical: Provides a standard for us in performing, teaching, or evaluating a skill Research: Once we describe, we can ask why? Problem with kinematics? Practical: Proper kinematics does not always mean proper force application

Basic Kinematic Concepts 1.Variables for Describing Motion 2.Reference Systems for Describing Motion of the Human Body & Its Segments 3.Guidelines for Describing Motion of the Human Body & Its Segments

Kinematic Variables Time Position Displacement & distance Velocity & speed Acceleration

Time – Temporal Analysis WHEN? HOW OFTEN? IN WHAT ORDER? HOW LONG? Most basic analysis Examples: Cadence Stride time Temporal patterning

Temporal Patterning

Stance Swing

Absolute vs. Relative Timing

Position position - location in space relative to some reference point Linear position (s) x,y,z coordinates Angular position (  ) Units WHERE?

Displacement & Distance Displacement (  s,  ) Final change in position Vector quantity Distance (  p,  ) Sum of all changes in position Scalar quantity HOW FAR? yUnits (m, °)

Velocity & Acceleration Velocity (v,  ) Vector quantity  position  time Units (m. s -1, °. s -1 ) Acceleration (a,  ) Vector quantity  velocity  time Units (m. s -2, °. s -2 ) Insight into forces/torques HOW FAST? HOW QUICKLY IS VELOCITY CHANGING?

Basic Kinematic Concepts 1.Types of Motion 2.Variables for Describing Motion 3.Reference Systems for Describing Motion of the Human Body & Its Segments 4.Guidelines for Describing Motion of the Human Body & Its Segments

Reference Systems: Linear +x -x -y +y +z horizontal vertical horizontal Must define origin of reference system to quantify kinematics.

0°0° 90° 180° 270°  rad ½ rev 3  /2 rad ¾ rev  /2 rad ¼ rev 2  rad 1 rev Absolute Reference Systems: Angular CCW +

Relative Reference Systems: Angular

Relative Reference Systems Fundamental Standing Position Anatomical Standing Position All 0  except 90  Forearm varies

Reference Systems for Measuring Joint Position & Displacement 00 90  140 

00 00 40  90 

Basic Kinematic Concepts 1.Types of Motion 2.Variables for Describing Motion 3.Reference Systems for Describing Motion of the Human Body & Its Segments 4.Guidelines for Describing Motion of the Human Body & Its Segments

1. Distinguish between motion & position of joints & segments. AB

2. Recognize that either segment can rotate about a joint.

3. Recognize that bones move linearly as well as angularly.

4. Understand that movement generally occurs in oblique planes around oblique axes.

5. When observing motion, look at the plane, down the axis.

Summary 1.Identify the system of interest 2.Identify the type(s) of motion of interest 3.Identify the reference system for the motion 4.Describe precisely the temporal & spatial characteristics of that motion using appropriate terminology for the situation Time Position Displacement (ROM) Velocity Acceleration

For the next lecture day: Lecture Topic #2 Subtopic C – Vector Algebra