ACSM's Introduction to Exercise Science, Chapter 9

Static biomechanics

the study of bodies, masses and forces at rest or in a constant unchanged motion

dynamic biomechanics

the study of bodies, masses, and forces when they are in motion

What significant events happened during the Renaissance period that contributed to the development of biomechanics?

De Vinci studied joints, anazlyzed muscles forces as origins/insertions
-Development of electromyography
-Isaac Newton published his basic laws

What is rectilinear motion? example?

all points on body move in a straight line, w/ no change in direction. Ex: cyclist coasting on bike

What is curvilinear motion? example?

All points on body move in a parallel line, but paths following movements are curved

What is a biomechanics system of interest? Example?

-An analysis of a specific body limb movement, or analysis of movement of the complete body
-analysis of walking patterns in someone who has otseoarthritis in their knees

How is the Sagittal plane used to describe movements of the body?

flexion, extension and hyperextension

How is the Frontal plane used to describe movements of the body?

abduction, adduction, lateral flexion, elevation and depression, deviation, eversion, and inversion.

How is the transverse plane used to describe movements of the body?

rotation, supination, pronation, abduction, and adduction

How is the other plane used to describe movements of the body?

circumduction

How is a Cartesian coordinate system used in a biomechanical analysis of movement?

Units are measured int he direction of either two or three primary axes. single direction or planar movements, such as running, cycling, or jumping, can be analyzed using a two dimensional cartesian coordinate system.

Describe the steps involved in a qualitative analysis of a soccer kick.

1. identifying the major question or questions of interest.
2. Determining the optimal perspective(s) from which to view the movement.
3. Identifying the distance from which to view the movement.
4. Determining the number of trials of the movement needed

Compressive force (compression)

force that tends to shorten or squeeze something, decreasing its volume

tensile force (tension)

a force that tends to stretch or elongate something.

shear force

force acting on a substance in a direction perpendicular to the extension of the substance

How does mechanical loading cause the deformation of an object such as bone?

deformation occurs when the external force causes a change in the shape or structure of an object or body component. When external force is applied to the human body, the structures of the body must withstand the force, if it is too much force, it may cau

Clinical biomechanist

a branch of biomechanics centered on improving the ability of an injured or disabled individual to perform activities of daily living, including work and leisure activities, physical activity, or exercise.

Ergonomist

ergonomics is the study of the interaction between humans, the objects they use, and the environments in which they function.

How does a biomechanist improve performance by changing technique, equipment, or training techniques?

-equipment improvement- improvind designs for the shoes, appeal,
-training improvement- improve performance
-techinque improvement-improve movement, may discover a new and more effective tech. for performing a sports skill.

Sequential movements

When segments of the body and joint rotations occur in a specific sequence or order

simultaneous movements

when a major movements of the body occur at the same time.

kinematics

the study of motion, including the pattersn and speed of movement of the body segments, without consideration given to the mass of the body or the forces acting upon it.

kinetics

the study of the effects of forces on the motion of a body or system of bodies, especially of forces that do not originate within the system itself.

clinical biomechanics

a branch of biomechanics centered on improving the ability of an injured or disabled individual to perform activities of daily living, including work and leisure activities, physical activity, or exercise.

sport biomechanics

a branch of biomechanics centered on improving sport performance by athletes through the improvement in movement techniques or the development of equipment.

linear motion

when all points of the body are moving in the same direction at the same speed, and travel the same distance

rectilinear translation

when all points on a body move in a straight line, the same distance, and with no change in direction.

curviliniear translation

occurs when all points on a body move the same distance but the paths followed by the points on the object are curved

angular motion

the motion of a body about a fixed point or fixed axis

general motion

occurs when the translation and rotation movements are combined.

anatomic reference position

an erect standing position with the feet slightly separated the arms hanging relaxed at the sides, and the palms of the hands facing forward.

directional terms

used to describe the relationship of body parts or the location of an external object with respect to the body

anatomic reference planes

the division of the body by three imaginary cardinal planes into three dimensions: sagittal, frontal and transverse

anatomic reference axes

the use of three axes for describing the rotation of the human body: mediolateral, anteropostieror, and longitudinal

cartesian coordinate system

a system in which the location of a point is given by coordinates that represent its distances from perpendicular lines that intersect at a point called the origin.

qualitative analysis

requires the progressive identification of the aspects critical to the movement through a systematic process that often requires the analyst to view multiple trials from different viewpoints.

inertia

tendency of a body to maintain its current state of motion whether motionless or moving with a 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, no matter how the body is positioned.

weight

force with which an object is attracted toward the center of the earth by gravity; weight depends on an objects mass and the strenght of the gravitational pull

pressure

force per unit area that one regious of a gas, liquid, or solid exerts on another region

volume

amount of space occupied by a three-dimensional object of region of space

density

measure of the quantity of some physical property(usually mass) per unit length, area or volume

torque

tendency of a force applied to an object to make the object rotate about an axis

impulse

change of momentum of a body or physical system over a time interval; equal to the force applied times the length of the time interval over which it is applied

mechanical loads

forces that act upon a body or object, including those from gravity, the muscles, and external to the body

eccentric

a movement that results in a lengthening of the muscle

torsion

the production of a force at one end of a body that results in a twisting motion, whereas the other end of the body remains fixed or moves in the opposite direction

mechanical fatigue

when the expected force production of a muscle, tendon, ligament, cartilage, or bone cannot be achieved or maintained.

forceful exertion

contributes to injury and pain by used in activities that require a large magnitude of force to perform a task; may easily lead to injury

awkward postures

contributes to injury and pain by using improper technique to perform a task can produce disabling injuries to active and supporting tissues and muscles

localized constant loads

contributes to injury and pain by occur between body tissues and objects in the environment and can cause increased compression and shearing on the tissues

repetitious motions

contributes to injury and pain by occur during repeated performance of tasks during the day and may cause injury through inflammation and repetitive stress.

sequential kinetic link principle

when segments of the body and joint rotations occur in a specific sequence or order

simultaneous kinetic link principle

when major movements of the body occur at the same time