Biomechanics 110

Define biomechanics:
- The study of the human body at rest and in motion using principles and concepts derived from physics, mechanics, and engineering.
- Examples: The relationship between biomechanics and exercise science.
Identify historic events in biomechanics development.
Describe important concepts of kinematics and kinetics.
Describe the importance of loading on body tissues.
Explain differences between clinical biomechanics and sport biomechanics.
Discuss important topics of study in biomechanics.

The study focuses on two main areas:
- Statics: Examines the bodies, masses, and forces at rest or moving at a constant velocity.
- Dynamics: Investigates bodies, masses, and forces that are accelerating or decelerating.

Focuses on improving the ability of individuals who are injured or disabled to perform activities of daily living.
Areas of concern include work, leisure activities, physical activity, and exercise.

Applies the laws and principles of mechanics and physics to enhance sport performance.
Objective is to improve movement techniques or develop better equipment.

Early 20th century industrial technology expansion necessitated the examination of physical and physiological aspects of industrial work.
Establishment of professional journals:
  - Journal of Biomechanics
  - Journal of Applied Biomechanics
  - Clinical Biomechanics

Historic Event	Date
Aristotle publishes "On the Motion of Animals."	ca. 384-322 BC
Galen publishes "On the Function of the Parts."	ca. 130-200
Andreas Vesalius publishes "On the Structure of the Human Body."	1543
Giovanni Alphonso Borelli publishes "De Moti Animalium."	1679
Jules Amar publishes "The Human Motor."	1920
W.O. Fenn publishes first cinematographic analysis of sprint running.	1929
Journal of Biomechanics is first published.	1968
Major advancements in wireless and digital technology.	ca. 2000-2010
International Society of Biomechanics is founded.
American Society of Biomechanics is founded.
International Society for Biomechanics in Sport is founded.
Journal of Applied Biomechanics is first published.
Clinical Biomechanics is first published.	1985

Linear Motion: All points of the body move in the same direction at the same speed and travel the same distance.
Angular Motion: Known as rotary motion or rotation; movement occurs around an axis of rotation.
General Motion: A combination of translation and angular movements.

Term	Definition
Anatomic reference position	Erect standing position with feet slightly separated, arms relaxed at sides, palms facing forward.
Directional terms	Describes the relationship of body parts or location of an external object relative to the body.
Anatomic reference planes	Body divided by three imaginary cardinal planes: sagittal, frontal, transverse.
Anatomic reference axes	Three axes for describing the rotation of the body: mediolateral, anteroposterior, longitudinal.

Used to quantitatively describe movement using spatial reference systems and standardized measurements.
Cartesian Coordinate System: The most commonly used system.
- Two directions: x (horizontal), y (vertical).
- Descriptors: Anterior, Posterior, Lateral, Medial, Anterolateral, etc.

Involves evaluating techniques exhibited by the performer and the performance outcome.
Example: A pitching coach observes a player's throwing technique to evaluate form.

Basic Concept	Definition
Inertia	Tendency of a body to maintain its current state of motion, whether motionless or moving with constant velocity.
Mass	Quantity of matter contained in an object.
Force	Something that causes a change in the motion of a body.
Center of gravity	Point around which the body's weight is equally balanced regardless of body position.
Weight	Force with which an object is attracted toward the center of the Earth by gravity.
Pressure	Force per unit area exerted by one region of gas, liquid, or solid on another.
Volume	Amount of space occupied by a three-dimensional object.
Density	Mass per unit volume of a physical substance.
Torque	Tendency of a force applied to make an object rotate about an axis.
Impulse	Change of momentum of a body over a time interval; equal to force times time interval.

Basic Concept	Definition
Compressive Force	Force that tends to shorten or squeeze, decreasing volume.
Tensile Force	Force that stretches or elongates something.
Shear Force	Force acting perpendicular to the extension of a substance.

Projectiles: Study of the movement of objects influenced by gravity.
Kinetic Link Principle:
- Sequential Kinetic Link Principle: Involves timing of movements; for example, in pitching, force begins at the foot and moves up to the hand.
- Simultaneous Kinetic Link Principle: Movements occur at the same time for efficiency.

Involves working with individuals who are injured or diseased.
Focuses on individualized rehabilitation techniques, wheelchair design, tissue repair, surgical techniques, and bone and tissue design.
Studying conditions such as osteoarthritis.

Examines the interaction between humans, objects, and their environments.
Aims to prevent workplace injuries and improve workforce return capacity post-injury.
Examples: Designing equipment for special populations, modifying living/working conditions, implementing changes to environments.
Example: Ergonomic keyboards to reduce strain.

Risk Factor	Contribution to Injury and Pain
Forceful exertion	High magnitude of force required may lead to injury.
Awkward postures	Improper technique can produce disabling injuries.
Localized constant loads	Can cause increased compression and shearing on tissues.
Repetitious motions	Can cause injury through inflammation and repetitive stress.

Examines human movement factors associated with exercise training and sport, focusing on performance improvement and injury prevention.
Areas of focus:
  - Technique improvement
  - Equipment improvement
  - Training enhancement
  - Injury prevention

Performance Technique	Performance Analysis	Change in Technique	Change in Performance
A baseball pitcher experiences a decrease in throwing velocity.	Coach observes the pitcher from different angles around the mound.	Suggests opening the front foot toward home plate.	Leads to hips opening sooner, generating force and increasing throwing velocity.
A swimmer has a slow start off the stand.	Biomechanist films swimmers using different starts and analyses for speed.	Recommends a change in foot placement on the block.	Results in greater force generation during water entry, improving speed.