Biomechanics Flashcards

Flashcards covering key vocabulary terms and definitions from a biomechanics lecture.

Biomechanics

The study of motion and the effects of forces relative to the body, applying the laws of mechanics and physics to human performance.

Linear Motion

Movement along a straight or curved line where all body parts move in the same direction at the same speed without rotation; also referred to as translation.

Rectilinear Motion

Linear movement that occurs through a straight line, often represented by the body as a whole or a certain point of the body.

Curvilinear Motion

Linear movement where objects move through a curved trajectory.

Angular Motion

Rotary movement about an axis where all body parts move through a rotational pathway, through the same angle, in the same direction, and at the same time.

General Motion

A combination of linear and angular motion, where the angular rotation of several body segments combine to produce linear motion of the body.

Distance

The path a body moves from one location to another.

Displacement

How far you finish from the start point in a set direction; a vector quantity with both magnitude and direction.

Speed

Measure of the distance an object travels per unit of time.

Velocity

Speed in a given direction, calculated by dividing displacement traveled by the time taken.

Acceleration

The rate at which the velocity of a body changes with respect to time; can be positive, negative (retardation), or zero.

Angular Distance

The exact length of an angular path.

Angular Displacement

The angle between the initial and final position of the body.

Angular Speed

Angular distance divided by time.

Angular Velocity

Angular displacement divided by time.

Angular Acceleration

The change in angular velocity divided by time.

Force

Any interaction (e.g., a push or pull) that, when unopposed, will change the motion of an object. Represented mathematically as F = MA.

Internal Force

Forces generated by structures of the body that interact to produce movement (e.g., action of muscles and tendons).

External Force

Forces that are the result of the interaction between the body and the environment (e.g., gravity, friction, air resistance, water resistance).

Contact Forces

Forces that act on objects that come into direct contact with one another (e.g., frictional forces, ground reaction forces).

Noncontact Forces

Forces that act on objects without coming into direct contact with one another (e.g., gravity).

Inertia

The amount of resistance to a change in an object’s state of motion; directly proportional to an object’s mass.

Momentum

A measure of the amount of motion possessed by a moving body; calculated as Mass x Velocity.

Impulse

The application of force over a period of time to change the momentum of an object; calculated as Force x Time.

Newton's First Law of Motion

A body continues in its state of rest or state of motion unless acted upon by force; also known as the Law of Inertia.

Newton's Second Law of Motion

The acceleration of a body is proportional to the force applied to it and inversely proportional to the object's mass; expressed as F=MA.

Newton's Third Law of Motion

For every action, there is an equal and opposite reaction; forces cannot act alone and must exist in pairs.

Levers

A rigid bar that pivots around a fixed point (axis or fulcrum), used to exert a force (effort) against a resistance (load).

First Class Lever

A lever system where the axis (fulcrum) is located between the force (effort) and the resistance (load).

Second Class Lever

A lever system where the axis is at one end, the resistance (load) is in the middle, and the force (effort) is applied at the opposite end.

Third Class Lever

A lever system where the axis is located at one end, the force is applied in the middle, and the resistance is applied at the opposite end.

Projectile Motion

The motion of an object propelled into the air or water and affected only by the forces of gravity and air resistance.

Angle of Release

The angle at which a projectile is released, which determines its trajectory shape, time in the air, and horizontal distance.

Speed of Release

The speed or velocity at which a projectile is released; the most critical factor in maximizing distance traveled.

Height of Release

The height at which a projectile is released, affecting the horizontal distance it will cover, provided all other factors are equal.

Parabola

Smooth symmetrical curve from the trajectory of a projectile when the landing height and release height are equal.

Balance

The ability to neutralize forces that disturb equilibrium; includes static and dynamic balance.

Static Balance

The ability to hold a stationary position.

Dynamic Balance

The ability to hold a moving position to execute an outcome.

Centre of Gravity

The theoretical point in an object where all of the body’s mass is equally distributed.

Line of Gravity

An imaginary vertical line passing downwards through the center of gravity to the ground or surface the person is on.

Base of Support

The area bound by the outermost regions of contact between a body and support surface.