BIOMECHANICAL COURSE
ENT 214
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Final exam 50%
Quizzes and assignments: 10%
Mid term: 10%
Lab : 30%
BASIC BIOMECHANICS
Define the terms biomechanics, static, dynamics,
kinematics, and kinetics and explain the ways in which
they are related.
Identify and describe the reference positions, planes,
and axes associated with the human body.
Define and appropriately use directional terms and joint
movement terminology.
Identify and describe the uses of available
instrumentation for measuring kinematics quantities.
What is biomechanics?
bio
mechanics
Application of mechanical principles in the
study of living organisms
Biomechanics/Mechanics
Statics : study of systems in constant
motion, (including zero motion)
Dynamics : study of systems subject to
acceleration
Biomechanics/mechanics
• Kinematics: study of the appearance
or description of motion
• Kinetics: study of the actions of forces
Mechanics
Static
Kinematics
Movement with
constant velocity
An area of physics that consists
of the study of motion and
the effect of forces on an object
Dynamics
Kinetics
Force acting on the
object at rest
and moving with
constant velocity
Kinematics
Movement with
acceleration
Kinetics
Force acting on the
object moving with
acceleration
KINESIOLOGY
Biomechanics
Kinematics
Linear
Angular
Position
Velocity
Acceleration
Position
Velocity
Acceleration
Kinetics
Linear
Force
Angular
Torque
KINESIOLOGY
The scientific study of human movement.
Human movement
•Identify discrete phases in an activity
•Describe segmental movements in each phases
•Identify major muscle contributors to each joint
movement
Rising from chair
•Movements of hip extension
•Knee extension
•Plantarflexion
BIOMECHANICS
The applications of mechanics to human movement
Human movement
•Describing motion characteristics of human movement
using parameters such as speed, direction, acceleration.
•Study on how motion is created through application
of forces both insides and outside the body.
Rising from chair
Measure and identify joint forces acting at the hip,
knee, and ankle along with the force between the foot
and the floor (all of which act together to produce
the movement up out of the chair)
BIOMECHANICS RESEARCH
DrOS (Housh, Housh and Johnson - 2003)
Developmental biomechanics
Evaluate fundamental movement patterns in
performing gross (crawling, walking – involve
large muscle group) and fine motor skills
(manipulating small objects, transferring
object – involve small muscle group).
BIOMECHANICS RESEARCH
Occupational Biomechanics
Focuses on providing safe and efficient working
environment, both indoors and outdoors.
 Better Safety equipment – helmets, shin
guards,footwear to protect from any work hazards.
 Safe and ergonomic working tools to minimize
overuse injuries of both upper and lower limbs
 Designing of mass public transportation –
airplanes,trains,boats and automobiles for safety and
efficiency.
 Close allied with the science of ergonomics
BIOMECHANICS RESEARCH
Rehabilitative Biomechanics
Observe movement patterns of individuals who
are either injured or/and disabled, provide
appropriate interventions which enable
injured and disabled person to function as
close to, if not normally.
Develop exercise equipment, supplementary
aids such as walkers, orthotics and even
substitution devices such as prostheses for
rehabilitation purposes.
BIOMECHANICS RESEARCH
Exercise and Sport Biomechanics
Describe technique and movement patterns, quantify
the contributions of joint actions to technique and in
some cases, to predict and evaluate optimal
conditions of performance
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Integrate the use of exercise machines for improving
strength, endurance, flexibility and speed.
Minimize sport related injuries and enhancing
performance
Make improvements on equipment such that it is
comfortable, easier to use, and provide a safe and
effective resistance for improving training and
performance.
Qualitative vs Quantitative Analysis
Qualitative: pertaining to quality (without
the use of numbers)
Quantitative: involve numbers
Both are important for biomechanical analysis of human
motion. Some rely on quantitative, some on qualitative
analysis.
ASSIGNMENT
In a group of two, write a summary of two activities
involving human motion analysis.
Identify the following items:
1. What are the problems that encourage the writers to do such
research? (10 marks)
2. What are the parameters involve in such analysis? (5 marks)
3. What are the equipments and method used in conducting the
experiments? (5 marks)
4. Brief explanation on the results (15marks)
5. What are the things to be considered in the future related to
the experiment? (15 marks)
ASSIGNMENT 1
•The assignment should be submitted
within a month from the first lecturer.
• Mark will be given according to
explanation given (easy to understand,
figures and other initiatives)
•Please use MICROSOFT WORDS to
write the assignment.
•Any late report will have penalties on
the marks.
Chapter 2
Kinematic Concepts for
Analyzing Human Motion
Identify and describe the reference positions, planes, and axes
associated with the human body.
Define and appropriately use directional terms and joint movement
terminology.
Identify and describe the uses of available instrumentation for
measuring kinematics quantities.
What is anatomical reference
position?
Erect standing position
with all body parts facing
forward.
Considered the starting
point for all body
segment movements
BODY SEGMENT NAMES
Head
Forearm
Upper Extremity
•AXIAL
•Accounting
50% of body weight
•Moves slower the other
parts of the body
APPENDICULAR
•The lower and upper extremity
•Away from trunk become smaller,
•faster and their movement
• is difficult to observe
Hand
NECK
Leg
Foot
Lower Extremity
TRUNK
Directional Terms
Superior: closer to
the head.
Inferior: farther
away from the head.
Medial: toward the
midline of the body.
Lateral: away form
the midline of the
body.
Directional Terms
Anterior: toward the front
of the body
Posterior: toward the
back of the body
Proximal: closer to the
trunk
Distal: away from the
trunk
Directional Terms
Superficial: toward the
surface of the body
Deep: inside the body
away from the surface
Reference Planes
Sagittal plane - in which
forward and backward
movements occur
Frontal plane - in which
lateral movements occur
Transverse plane - in
which rotational
movements occur
Reference Axes
Mediolateral axis - around
which rotations in the
sagittal plane occur
Anteroposterior axis around which rotations in
the sagittal plane occur
Longitudinal axis around which rotational
movements occur
FORM OF MOTION
Linear
Motion
Rectilinear
Motion
= along a straight line
Curvelinear
Motion
= along a curved line
+
Angular
Motion
= rotation around an axis
=
General
Motion
= Combination of linear motion and angular motion
Forms of Motion
Linear motion: motion along a line
Rectilinear motion:
(along a straight line)
Curvilinear motion:
(along a curved line)
GENERAL MOTION
General motion: a combination of linear
and angular motion (includes most
human motion)
THE MOVEMENTS DESCRIPTION
The six basic movement descriptors
Flexion, extension,
Abduction, adduction,
Rotation (medial and lateral).
Specialized movement descriptors
Head and trunk only
Lateral flexion
Shoulder girdle movement
Elevation, depression
Protraction and retraction (adduction and abduction in
scapula)
Upward and downward rotation
THE MOVEMENTS DESCRIPTION
Specialized movement descriptors
Arm and thigh
Horizontal abduction and adduction
Forearm
Pronation and supination
Wrist joint
Radial and ulnar flexion
Foot
Plantar and dorsiflexion
Inversion and eversion
Pronation and supination
MOVEMENTS IN THE SAGITTAL PLANE
Flexion
Anteriorly directed sagittal plane rotations of the head,
trunk, upper arm, forearm, hand and thigh.
Posteriorly directed sagittal plane rotation of the lower
leg.
Bending movement in which the relative angle of the
joint between 2 adjacent segements decreases.
Extension
Return the body to the anatomical position.
Straightening movement in which the relative angle of
the joint between 2 adjacent segments increases as
the joint return to the reference position.
Hyperextension
MOVEMENTS IN THE SAGITTAL PLANE
Hyperflexion (Hyperextension) – movement that
goes beyond the normal range of flexion (extension
- movement that goes beyond the anatomical
reference position and opposite of flexion)
SAGGITAL PLANE MOVEMENT
Dorsiflexion: bringing the top of the foot toward the Tibia,
angle between the leg and foot decrease.
Plantarflexion: opposite motion of Dorsiflexion, bottom of
the foot moves down and the angle between the leg and
foot increase.
Dorsiflexion
Plantar flexion
Movements in the frontal plane
• Abduction & adduction – move a
body segment away from and closer to
the midline of the body, respectively.
Abduction
Adduction
Lateral flexion
 Bending to one side.
The term lateral flexion
is used to describe
motions of the trunk and
neck.
Elevation & depression
 Movement of shoulder
girdle in the superior
and inferior direction
Lateral flexion
Elevation
Depression
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v
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n
Inversion & eversion
 Inward and outward
rotation of the sole
of the foot,
respectively.
c
a
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s
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o
Radial & ulnar
deviation
Side-to-side movement
of the hand at the wrist,
toward and away from
the thumb, respectively.
a
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Eversion
Inversion
Movements in the transverse plane
Left & right rotation
(head, neck, trunk)
Medial (internal) &
lateral (external)
rotation – toward
midline and away from
midline, respectively.
Medial
rotation
Lateral
rotation
Supination – Outwards or
upwards.
Frontal Plane
Rotation of a body part, usually
the hand and forearm so that
the palm is down.
Transverse Plane
Rotation of the forearm,
outwards and inwards.
In the foot (subtalar joint), it is
a combination of motions
resulting in a position such
that the foot is abducted and
everted.
Pronation – Inwards or
downwards.
Oppose the supination
Pronat Supin
ion ation
**Horizontal abduction & adduction
Adduction - from
lateral to anterior
position (also called
horizontal flexion)
Abduction – from
anterior to lateral
position (also called
horizontal extension)
Horizontal
adduction
Horizontal
abduction
Spatial Reference Systems
Useful for standardizing descriptions
of human motion.
Most commonly used is the Cartesian
coordinate system.
Human body joint centers are labeled
with numerical x and y coordinates.
Spatial Reference Systems
Y
(x,y) = (3,7)
(0,0)
X
Cartesian coordinates of the hip
Spatial Reference Systems
y
x=y=+
x=+
y=+
x
(0,0)
x=y=-
x=+
y=-
Coordinates can be both positive and
negative.
TOOLS FOR MEASURING KINEMATIC
QUANTITIES
Objective: To determine the coordinates of the marked points as a function of time
Direct Measurement Techniques
Goniometers
Special Joint Angle Measuring Systems
Accelerometers
Indirect Measurement (Imaging) Techniques
Cinematography
Television
Optoelectric technique
Others indirect measurement
TOOL FOR KINEMATICS MEASUREMENT
OPTICAL SYSTEM
Cinematography (movie cameras)
Type of film use depend on lighting available,
Television
The major difference between Cinematography and Television is the frame rate (The
number of images that are shown or sent each second) , where the Television has a
fixed frame rate (50 or 60 Hz).
Television has high enough field rate for most movement, but too low for quantitative
analysis of rapid athletic movement.
•Standard video camera – reflective marker produces a trailing edge and blurs image
when there is a rapid movement.
•CCD cameras – eliminates both blurring and skewing
•Infrared cameras – reflected infrared lights from the markers is the only lights picked
up by the camera.
Optoelectric Techniques optical
Subject wear tiny infrared lights on
each desired anatomical landmarks.
The lights were flashed sequentially,
and detected on a special camera.
Non Optical techniques
Magnetic System – Sensors are linked
by cables to a computer.
Electromagnetic System – the
subjects wear a body suit.
Acoustic Systems –Sonar uses
reflected sound waves.
Advantages and Disadvantages of Optical Systems
Advantages
Most systems are not limited to the numbers of markers
used.
Encumbrance to movement is minimal (lightweigth reflective
markers).
Inexpensive (VCR and TV cameras).
TV and Cine can be replayed for teaching purposes or for
qualitative analysis of the total body movement.
Disadvantages
Most multiple cameras are expensive.
Some imaging system cannot be used outdoor.
TUTORIAL FOR NEXT WEEK
In a group of 5, write a five minute presentation on the
motion capture system. The presentation will be
done during the tutorial session.
The purpose of the presentation is to identify and
describe the type of kinematics measuring
equipment that are currently available.
Includes:
1. Classification (imaging – Cinematography,
Television, Optoelectric technique; Other techniques
- Magnetic, electromagnetic, acoustic or any other
technique).
2. Advantage and disadvantages of the system (cost,
limitation in place, and other factors to be
considered)