PBS Fundamentals of Physics and Applications to Human Biomechanics

These flashcards cover key terms related to forces, biomechanics, and Newton's laws, aiding in the understanding of human movement and stability.

Vector

A mathematical entity that has both magnitude and direction.

Scalar Quantity

A quantity that is described by magnitude only.

Torque

Measuring the ability to cause rotation, calculated as t = F⊥ . l, where l is the lever arm.

Mechanical Equilibrium

The state where the sum of forces and torques acting on a body equals zero.

Moment Arm

The shortest distance from the pivot point to the line of action of the force.

Newton's First Law of Motion

An object at rest remains at rest and an object in motion continues with constant velocity unless acted upon by a net external force.

Newton's Second Law of Motion

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

Newton's Third Law of Motion

For every action, there is an equal and opposite reaction.

Oblique Force

A force applied at an angle, which results in a smaller moment arm.

Center of Gravity (COG)

The point at which the body's mass is equally distributed in all directions, influencing stability.

Isotonic Contraction

Muscle contraction where the muscle shortens or lengthens while maintaining constant tension.

Joint Reaction Forces

Forces that act on the joint surfaces as a result of muscle tension and external loads.

Posture

The alignment and positioning of the body in static or dynamic states.

Equilibrium

The state of balance where all acting forces and torques equal zero, maintaining joint stability.

Force Component Resolution

The process of breaking down a force into its parallel and perpendicular components.

Line of Gravity

An imaginary vertical line that extends from the center of gravity to the ground, critical for balance.

Friction

A force that opposes motion between two surfaces in contact.