Basic Kinematics
Course Content
I.
II.
Introduction to the Course
Biomechanical Concepts Related to
Human Movement
III. Anatomical Concepts Related to Human
Movement
IV. Applications in Human Movement
Course Content
I.
II.
Introduction to the Course
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
Kinematics
Kinetics
Dynamics
Motionless
Kinematics
Kinetics
What is kinematics?
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Spatial and temporal characteristics
Qualitative or quantitative
Linear & angular motion
Why use kinematics?
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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
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Time
Position
Displacement & distance
Velocity & speed
Acceleration
Time – Temporal Analysis
WHEN?
HOW OFTEN?
IN WHAT ORDER?
HOW LONG?
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Most basic analysis
Examples:
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Cadence
Stride time
Temporal patterning
Temporal Patterning
Temporal Patterning
Stance
Swing
Absolute vs. Relative Timing
Position
WHERE?
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position - location in space relative to some
reference point
Linear position (s)
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x,y,z coordinates
Angular position ()
Units
Displacement & Distance
HOW FAR?
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Displacement (s, )
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Final change in position
Vector quantity
Distance (p, )
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Sum of all changes in
position
Scalar quantity
Units (m, °)
Velocity & Acceleration
HOW QUICKLY IS
VELOCITY
CHANGING?
HOW FAST?
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Velocity (v, )
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Vector quantity
position  time
Units (m.s-1, °.s-1)
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Acceleration (a, )
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Vector quantity
velocity  time
Units (m.s-2, °.s-2)
Insight into
forces/torques
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
+y
horizontal
-x
vertical
+x
Must define origin of
reference system to
quantify kinematics.
horizontal
+z
-y
Absolute Reference Systems:
Angular
/2 rad
90°
¼ rev
CCW +
180°
0°
 rad
½ rev
2 rad
1 rev
270°
3/2 rad
¾ rev
Relative Reference Systems:
Angular
Relative Reference Systems
All Joints @ 0except
•Ankle @ 90
•Forearm varies
Fundamental
Standing
Position
Anatomical
Standing
Position
Reference Systems for Measuring
Joint Position & Displacement
90
140
140
0
0
0
40
90
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.
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.
2.
3.
4.
Identify the system of interest
Identify the type(s) of motion of interest
Identify the reference system for the motion
Describe precisely the temporal & spatial
characteristics of that motion using appropriate
terminology for the situation
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Time
Position
Displacement (ROM)
Velocity
Acceleration
For the next lecture day:
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Lecture Topic #2
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Subtopic C – Vector Algebra