Biomechanics Vocabulary

Flashcards covering key vocabulary and definitions related to Biomechanics, including types of motion, Newton's Laws, levers, projectile motion, and balance.

Biomechanics

The study of motion and the effects of forces relative to the body; it applies the laws of mechanics and physics to human performance.

Linear Motion

Movement along a straight or curved line where there is no rotation and all body parts move in the same direction at the same speed.

Rectilinear Motion

Linear movement that occurs through a straight line.

Curvilinear Motion

Linear movement where objects move through a curved trajectory.

Angular Motion

Rotary movement about an axis where all parts of a body 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. Human movement usually consists of general motion rather than purely linear or angular motion.

Distance

The path of a body as it moves from one location to another.

Displacement

How far you finish from your start point in a set direction; a vector quantity.

Speed

Measure of the distance an object travels per unit of time. Speed = Distance / Time

Velocity

Speed in a given direction. Velocity = Displacement / Time

Acceleration

The rate at which the velocity of a body changes with respect to time. Acceleration = (Final velocity - Initial velocity) / Time

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

Final angular velocity minus initial angular velocity divided by time.

Force

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

Inertia

Describes the amount of resistance to a change in an object’s state of motion. The greater an object’s inertia, the greater the force required to initiate its movement or change its state of motion.

Newton's 1st Law

A body continues in its state of rest or state of motion unless acted upon by force. Also referred to as the Law of Inertia.

Newton's 2nd Law

The acceleration of a body is proportional to the force applied to it and inversely proportional to the object's mass. Also referred to as the Law of Acceleration and can be expressed as F=MA.

Newton's 3rd Law

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

Momentum

A measure of the amount of motion possessed by a moving body i.e. Momentum = Mass x Velocity

Impulse

The application of force over a period of time to change the momentum of an object. Impulse = force × time

Conservation of Momentum

The principle that states the total momentum of two objects before and after impact are equal. This occurs when a perfectly elastic collision occurs, i.e., where no energy is lost to sound and heat.

Lever

A rigid object that is used with a fulcrum or pivot point to multiply the mechanical force that can be applied to another object.

Axis (Fulcrum)

The pivot point around which the lever rotates.

Resistance (Load)

The weight or load to be moved by the lever.

Force (Effort)

The application of force or effort, e.g., muscular force to move the resistance.

1st Class Lever

Lever with the axis located in the middle, with the force and resistance on either side (ARF or FLE).

2nd Class Lever

Lever with the axis located at the end, with the resistance in the middle and force applied at the end (ARF or FLE).

3rd Class Lever

Lever with the axis located at one end, with the application of force in the middle and resistance applied at the opposite end (ARF or FLE).

Projectile Motion

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

Trajectory

The path of a projectile.

Angle of Release

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

Speed of Release

The speed or velocity at which a projectile is released, which determines the height and length of the trajectory.

Height of Release

The height at which a projectile is released, affecting the horizontal distance it will cover.

Parabola

When the landing height and release height are equal, the trajectory of a projectile forms a smooth symmetrical curve.

Balance

The ability to neutralise forces that disturb equilibrium.

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 centre 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.