Download Anatomical basics of biomechanics

Anatomical basics of biomechanics
Katarzyna Kozera
15.10.2013
Kinesiology
• by definition, is the study of
movement
• kinesiology brings together the
fields of anatomy, physiology,
physics, and geometry, and relates
them to human movement
• kinesiology applies to the
mechanical principles,
musculoskeletal anatomy, and
neuromuscular physiology
Biomechanics
• Biomechanics has been defined as the study of the movement of
living things using the science of mechanics (Hatze, 1974)
BIO = LIVING
MECHANICS = FORCES & EFFECTS
• The application of mechanics to the living organism involves the
principles of anatomy and physics in the descriptions and
analysis of movement
• Has many diverse applications to all biological systems
• The study of biological structures, processes and functions by
applying the methods and principles of mechanics
Why?
How?
Anything that moves, lives
​Everything that lives, moves
The human body
Skeleton system
Skeleton system
• is made up of numerous bones
• is the rigid framework of the humanbody
• it gives support and shape to the body
• it protects vital organs such as the brain, spinal cord, and
heart
• it assists in movement by providing a rigid structure for
muscle attachment and leverage
• it manufactures blood cells in various locations
• calcium and other mineral salts are stored throughout all
osseous tissue of the skeletal system
Articular system
Articular system
• joint is a connection between twobones
• joints have several functions, perhaps the most
important is to allow motion
• joints also help to bear the weight of the body and to
provide stability
• joints also contain synovial fluid, which lubricates the
joint and nourishes the cartilage
Muscular system
Muscular system
• when a muscle contracts, it knows no direction;it
simply shortens
• muscles are attached to bones and cross at least one
joint, so when a muscle contracts, one end of the joint
moves toward the other
?
Structure creates function
​Function governs structure and evolution
The body is a unit
Applications of biomechanics
• Improvement of performance
• effective movement involves: anatomical factors,
neuromuscular skills, physiological capacities, and
psychological/cognitive abilities
• Technique changes and instructions allow to improve
performace
• In sports where technique is the dominant factor rather than
physical structure or physiological capacity
• Reduction or treatment of injury
• providing information on the mechanical properties of tissues,
mechanical loadings during movement, and preventative or
rehabilitative therapies
The science of mechanics
• Rigid-body mechanics – the object being analyzed
is assumed to be rigid and the deformations in its
shape so small they can be ignored
• Deformable-body mechanics – how forces are
distributed within a material, and can be focused at
many levels (cellular to tissues/organs/system) to
examine how forces stimulate growth or cause
damage
• Fluids mechanics – is concerned with the forces in
fluids
Static system
• Statics is the study of objects at rest or in uniform
motion, which are moving at a constant speed in a state
of equilibrium
• Equilibrium is a balanced state in which there is no
acceleration
Dynamic systems
• Dynamics is the study of objects being accelerated by the
actions of forces, deals with the changes in motion brought
on by unbalanced forces
• Can be divided into kinetics and kinematics
• Kinematics is motion description, are those time, space, and mass
aspects of a moving system
• Kinematics examines how, when, and where a body moves
• Kinetics is concerned with determining the causes of motion, are
those forces causing movement
• The internal and external forces that cause motion or cause a body
to remain at rest, and the interactions betweenthese forces
Force–Motion
• Unbalanced forces are acting on our bodies or objects
when we either create or modifymovement
Force–Time
• Not only the amount of force that can increase the
motion of an object, also the amount of time over
which force can be applied also affects the resulting
motion
Inertia
• Can be defined as the property of all objects to resist
changes in their state of motion
• Newton’s first law of motion outlines this principle
Range of Motion
• The overall motion used in a movement and can be
specified by linear or angular motion of the body
segments
Balance
• Person's ability to control their body position relative to
some base of support
• Stability and mobility of body posture are inversely
related
Coordination Continuum
• That determining the optimal timing of muscle actions
or segmental motions depends on the goal of the
movement
Segmental Interaction
• The forces acting in a system of linked rigid bodies can
be transferred through the links and joints
Kinetic chain
• in engineering terms, a kinetic chain consists of a
series of rigid links connected in such a way as to allow
motion
• because these links are connected, movement of one
link causes motion at other links in a predictable way
• in the human body:
• closed kinetic chain
• open kinetic chain
Close kinetic chain (CKC)
Open kinetic chain (OKC)
•
distal segment is fixed (closed)
• proximal segment(s) moves
• distal segment is free to move
•
(open)
• proximal segment(s) can
remain stationary
motion at one joint produce motion
at all of the other joints in the
system in a predictable manner
The benefits of close kinetic chain
• more specific
• more functional
• safer
• increased component joint compressive forces leading
•
•
•
•
•
to increased joint stability
increased agonist/antagonist muscle coactivation
decreased component joint shear forces
replicated more functional movement paterns
stimulated dynamic joint stabilization
proprioception
Open kinetic chain
• increase component joint
shear forces
• decrease component joint
compressive forces
• replicate single movement
paterns
• increase agonist/synergist
muscle coactivation
Points to remember
1.
2.
2.
3.
3.
4.
The body is a unit
Anything that moves, lives
​Everything that lives, moves
Structure creates function
​Function governs structure and
evolution
The natural application of biomechanical
principles is in qualitative analysis of
human movement
Thank you for your attention
Katarzyna Kozera