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 BodyMechanics
Statics Dynamics
Constant Velocity Motionless
Kinematics Kinetics
Kinematics Kinetics
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
Temporal PatterningStance 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?
Units (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°
90°
180°
270°
rad½ 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 Joints @ 0except•Ankle @ 90•Forearm varies
Reference Systems for Measuring Joint Position & Displacement
0
90
140140
0
0 40 9090
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.
A B
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 interest2. Identify the type(s) of motion of interest3. Identify the reference system for the motion4. 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
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