Human Movement and Biomechanics Review

A comprehensive set of flashcards covering human movement analysis, coaching styles, constraints, biomechanical forces, Newton's Laws, linear and angular motion, and principles of stability and levers.

Qualitative analysis

Description of the qualities of human movement without the use of numbers, involving preparation, observation, evaluation, and error correction.

Quantitative analysis

Description of the qualities of human movement using numbers.

Direct coaching

A rigid coaching style whereby the coach makes all the decisions, ensuring performers are always on task but preventing them from making decisions themselves in game situations.

Constraints

Boundaries that shape a learner’s movements, cognitions and decision making.

Individual constraints

Personal factors such as body size, fitness level, decision making skills, and technical skills.

Environmental constraints

Factors from the physical environment or social/cultural environment.

Task constraints

Factors involving rules, equipment, field dimensions, team size, and instructions used to develop skills and tactical awareness.

Socio-cultural influences

Impacts the learners opportunity to be involved in the sport, including family, available resources, geographic location, and access to equipment or coaches.

Force

A push or a pull acting on an object, defined by the formula $\text{Force} = \text{mass} \times \text{acceleration}$.

Biomechanics

The study of living things from a mechanical perspective.

Friction

Opposes the motion of an object and occurs when 2 surfaces come into contact with one another; requires greater force to overcome.

Drag Force

Air or wind resistance that opposes the direction of motion and slows an object down.

Gravitational force

The force of attraction between two bodies or objects, equal to $9.8,m/s^2$ on Earth, which pulls objects down.

Weight

The force exerted on the body by gravity, defined by $\text{Weight} = \text{mass} \times \text{gravity}$.

Mass

The amount of matter an object is made up of.

Inertia

The tendency of a body to resist change in its state of motion (rest or constant velocity); greater mass results in greater inertia.

LINEAR Momentum

A measure of the amount of motion an object has and its resistance to changing that motion, calculated as $\text{Momentum} = \text{mass} \times \text{velocity}$.

Conservation of Momentum

The principle that the total momentum of a system before a collision is equal to the total momentum after the collision.

Summation of Momentum

The sequential and coordinated movement of body segments from large muscles to small muscles to produce maximum velocity.

Impulse

The product of force and the time period over which it is applied, equal to the change in momentum: $\text{Impulse} = \text{Force} \times \text{Time}$.

Newton's First Law

The law of Inertia: A body will remain at rest or in uniform motion in a straight line unless acted upon by an external force.

Newton's Second Law

The law of acceleration: A force applied to an object will produce a change in motion in the direction of the applied force, directly proportional to the size of the force.

Newton's Third Law

The law of action-reaction: For every action there is an equal and opposite reaction.

Angular Motion

Movement of a body part around an axis of rotation.

Torque

A rotational force (push or pull) that makes an object rotate; it describes force in angular motion.

Angular Momentum

The quantity of angular motion of an object, calculated as $\text{Momentum} = \text{Angular velocity} \times \text{Moment of inertia}$.

Moment of Inertia

The resistance of an object to changes in its angular motion; mass closer to the axis increases velocity, while mass further away decreases velocity.

First law of angular motion

The angular momentum of a body remains constant unless acted upon by an external torque.

Second law of angular motion

A torque applied to an object produces a change in angular motion in the direction of the torque, directly proportional to the torque size and inversely proportional to the moment of inertia.

Third law of angular motion

For every torque there is an equal and opposite torque.

Conservation of angular momentum

The angular momentum of a system remains constant throughout a movement provided no external turning moment acts on it.

Linear motion

The movement of a body along a straight or curved path with all body parts moving in the same direction at the same speed.

Linear Distance

Measures the path travelled from start to finish.

Linear Displacement

How far an object is from the initial position to the final position.

Linear speed

Calculated as $\frac{\text{Distance}}{\text{time}}$.

Linear Velocity

Calculated as $\frac{\text{Displacement}}{\text{time}}$.

Linear Acceleration

The change in velocity over a given period of time, measured in $m/s^2$, which can be positive, negative, or zero.

Eccentric force

A force that does not act through the centre of gravity, causing a turning effect or torque.

Angular distance

The sum of all angular changes of a rotating body.

Angular acceleration

The change in velocity calculated as $\frac{\text{final velocity} - \text{initial velocity}}{\text{time}}$.

Angular displacement

The difference between the initial and final angular position of a rotating body.

Angular Speed

The angular distance travelled divided by the time taken to cover the distance.

Angular velocity

The rate of change of angular displacement over time.

Projectile

An airborne body or object that is only affected by forces of gravity and air resistance.

Angle of Release

The angle at which an object is projected; $45$ degrees is best for distance.

Speed of Release

The speed at which an object is propelled into the air, composed of vertical and horizontal components; greater speed leads to further distance.

Height of release

The difference between the height of release and the landing height; a higher release height increases travel distance.

Equilibrium

State where there are no unbalanced forces or torques acting; heavier mass makes it harder to disturb.

Balance

The ability to control equilibrium; improved by lowering COG, increasing BOS size, increasing mass, or increasing friction.

Stability

The resistance to disruption of equilibrium.

Static Equilibrium

When a body is not moving or rotating, and the sum of all forces acting on it is $0$.

Dynamic equilibrium

The state in which the body or object is moving with a constant velocity.

Base of Support

Bound by the outside edges of body parts in contact with a surface; a larger BOS increases stability.

Centre of gravity

The point around which the body’s weight is balanced; a lower COG increases stability.

Line of Gravity

The direction in which gravity acts through the centre of gravity; stability is decreased if the LOG is outside the BOS.

Body Mass

Factors into the force required to move an object and disrupt its equilibrium; greater mass requires greater force.

Levers

A simple machine consisting of a rigid bar that rotates around an axis to exert force.

Third Class Lever

A lever where the force is located between the axis and the resistance, such as a bicep curl.

Mechanical advantage

The ratio calculated as $\frac{\text{Force arm}}{\text{Resistance arm}}$; if less than 1, there is greater range of motion and speed but more force is required.

Air and Water Resistance

A force opposing the motion of an object as it moves through air or water.