Definitions (Bones) Flashcards
What is Biomechanics?
The study of how mechanical principles influence a living organisms structure and movement.
What is distance?
Spatial separation of two or more points, or ‘change in position’ (m)
What is displacement?
Net change in position from start to finish (m)
What is speed?
Distance travelled / time (m.s-1)
What is velocity?
Change in position (displacement) over time (m.s-1)
What is acceleration?
Rate of change of speed (m.s-2)
What is mass?
Quantity of matter which a body contains (kg)
What is weight?
The force acting on an object due to gravity; Mass x acceleration due to gravity (N) where g = 9.81m.s-2
What is force?
A ‘push or pull’ resulting from contact between 2 objects (exception = gravity)
F = ma (N = kg.m.s-2) = rate of change of momentum;
What is moment (torque)?
M = F x distance (N.m); Torque is produced by a force acting at a distance from the centre of rotation (COR). Causes rotation.
What is moment arm?
Length of a line perpendicular to the force vector and the COR
What is internal moment?
Moment generated by internal forces i.e. from muscles, ligaments
What is external moment?
Moment generated by external forces e.g. gravity, weights
What is momentum?
mu (kg.m.s-1)
What is work?
Force required to move an object a certain distance W = F x d (J, joule)
What is energy?
Capacity to do work. J = N x m
What is power?
rate of work, work / time (watt, W = N.m.s-1 = J.s-1
What is statics?
Study of forces acting on a body at rest or moving with constant velocity.
i.e. when the body is in static equilibrium. Provides a simplified way of studying the forces acting on the body and joint mechanics.
What is kinematics?
(‘kinema’ = movement) describes the motion of objects with no reference to the mass of those objects nor the forces which cause the motion. (range of motion, velocity, acceleration)
What are kinetics (dynamics)?
(‘kinesis’ = to move) the study of motion and its causes (forces)
What is Newton’s First Law?
An object remains at rest (or continues moving at a constant velocity) unless acted upon by an unbalanced external force.
What is Newton’s Second Law?
If there is an unbalanced force acting on an object, it produces an acceleration in the direction of the force, directly proportional to the force (f=ma).