Concepts of Biomechanics Flashcards
Biomechanics
The study of the mechanical laws governing movement of living organisms
Kinesiology
The study of the mechanics of human movement in exercise, everyday life, and sport.
Anatomical position
The anatomically neutral body position facing forward with the arms at the sides of the body and palms and toes facing straight ahead.
Frontal plane
Divides the body into anterior and posterior planes (hip and shoulder abduction)
Sagital plane
Divides the body into left and right halves (squat)
Transverse plane
Divides the body into inferior and superior halves (anything with rotation)
Range of motion
Measurements of movement around a specific joint or body part
Balance
An even distribution of weight enabling someone or something to maintain its center of gravity within a base of support
Equilibrium
A state in which opposing forces or influences are balanced
Stability
The ability to control and maintain control of joint movement or body position.
Base of support
The area beneath an object or person that includes every point of contact that the object or person makes with the supporting surface
Gravity
The attraction between objects and the Earth.
Dynamic balance
The ability to remain upright and balanced when the body and/or arms and legs are in motion.
Muscular force
Involves the contraction of a muscle while exerting a force and performing work. It can be concentric (shortening), eccentric (lengthening), or isometric (tension without joint movement
Static balance
The ability to remain upright and balanced when the body is at rest
Mass
The amount of matter in an object.
Weight
The gravitational force of attraction on an object
Line of gravity
A vertical line straight through the center of gravity.
Joint mobility
The degree of movement around a joint before movement is restricted by surrounding tissues.
Joint stability
The ability of the muscles around a joint to control movement or hold the joint in a fixed (stable) position
Laws of motion
The ability of the muscles around a joint to control movement or hold the joint in a fixed (stable) position
Force
The interaction that creates work or physical change. Its components are magnitude, direction, point of application, and line of action
Inertia
The resistance to action or change and describes the acceleration and deceleration of the human body.
Acceleration
The rate of change of velocity
Deceleration
A special type of acceleration where a person or object is slowing down
Velocity
The speed of an object and the direction it takes while moving
Force- velocity curve
A representation of the inverse relationship between force and velocity in muscle contraction.
Momentum
The quantity of motion of a moving body, measured as a product of its mass and velocity.
Speed
The ability to move the body in one direction as fast as possible
Ground reaction force
The force the ground exerts on a body it is in contact with
Friction
The resistance of relative motion that one surface or object encounters when moving over another.
Compression force
The force of two surfaces pressing toward one another.
Tensile force
The force when two surfaces pull apart from one another.
Shear force
The force of two surfaces moving across one another.
Muscular contraction
The shortening or resistance to lengthening of a muscle fiber.
Linear motion
Movement along a line, straight or curved.
Angular motion
Rotation around an axis.
Axis
Rotation around an axis.
Displacement
The distance an object is displaced from a starting point.
Distance
The total or sum of the length an object travels
Angular displacement
The change of location of an object that is rotating about an axis.
Linear displacement
The distance an object moves in a straight line.
Mechanical advantage
The ratio of force that creates meaningful movement compared to the force applied to generate the movement.
Work
Force times distance measured in foot-pounds
Power
The combination of strength and speed—the ability for a muscle to generate maximal tension as quickly as possible.
Mechanical work
The amount of energy transferred by a force, the product of force and distance.
Levers
A rigid or semirigid bar rotating around a fixed point when force is applied to one end
Fulcrum
The point on which a lever rests or is supported and on which it pivots
Effort arm
The portion of the lever arm between the applied effort and the axis
Lever arm
The rigid bar portion of a lever that rotates around the fulcrum.
Resistance arm
The portion of the lever arm between the load and the axis.
Moment arm
The perpendicular distance between the fulcrum and the line of the force being applied.
Torque
Force applied that results in rotation about an axis.
Rotary motion
The movement around a fixed axis moving in a curved path.
Force arm
The distance between the fulcrum and the force or load application in a lever.
Origin
The proximal muscular attachment point to a bone.
Insertion
The distal muscular attachment point to a bone.
Agonist muscle
The primary muscle used for a mechanical movement
Antagonist
Muscle(s) opposing the mechanical movement of a prime mover.
Sherrington’s law of reciprocal inhibition
A law that states that for every muscle activation, there is a corresponding inhibition of the opposing muscle
Stabilizer muscles
The muscles playing the role of stabilizing or minimizing joint movement
Length-tension relationship
The amount of tension a muscle can produce with respect to its length.
Force-couple relationship
Two or more muscles acting in different directions that influence the rotation of a joint in a specific direction.
Muscle synergies
The activation of a group of muscles to generate movement around a particular joint.
