Definitions: Motion Term Definition Sporting Example Motion The movement that results from a physical force. This is usually a muscular force but can also be a result of a force created by the environment. Throwing a jab in boxing. A physical force is created by the contraction of the tricep and pecs. Biomechanics The analysis of human movement and the mechanical laws that relate. Sprinters will study biomechanics in detail in order to know how to move their body in the fastest way possible to run the quickest times. Kinematics A part of Biomechanics that is purely concerned with motion but not the masses or forces involved. Golfers might focus on kinematics in order to perfect their golf swing. They would then worry about external forces, such as weather conditions, at a later point. Linear Motion One dimensional motion (movement resulting from a physical force) along a straight line. A straight position in diving, usually the end part of a dive where the body is stretched out and moves down in a straight line. Rectilinear Motion A kind of linear motion where the direction of the velocity remains constant and the path of the motion is a straight line. When a goalkeeper rolls a football to a defender the ball travels in a rectilinear motion Curvilinear Motion Motion of an object moving along a curved path The arc on a basketball shot from a long distance is an example of curvilinear motion. Random Motion Motion of an object with no specific path which can undergo sudden changes in direction. Kicking a football along uneven ground as the ball would potentially bounce or roll in any random direction. Angular Motion Motion around a curved path but with a constant angular velocity. Running around the corners on an athletics track. You are running along a curved path but the curve has a constant angular velocity unlike, for example, running around a cone in a warm up where you don't have a set path to follow. Don’t know if I’ve understood this properly, can’t really tell the difference between Angular motion and curvilinear motion. General Motion A combination of both linear and angular motion. Running. As the trunk moves in a linear motion and the limbs move in an angular motion. Vector Quantity A quantity that has both magnitude and direction. Acceleration, e.g. building up speed for a long jump in a straight line towards the sand Scalar Quantity A quantity that only has magnitude and not direction. Mass, e.g. the amount of weight on the bar for a deadlift as this cannot be measured in distance. Speed The ability to move parts or all of the body as fast as possible. In the 100m sprint athletes need as much speed as possible in order to win the race. Velocity The speed of a motion in a given direction. When shooting a good freekick the ball will travel towards the top corner at a high velocity Acceleration How quickly an athlete can increase velocity. In rugby, wingers need good acceleration so they can reach their top speed quickly and get to the tryline before being caught by a defender. Deceleration How quickly an athlete can decrease velocity. In basketball deceleration can be used to quickly come to a stop and shoot the ball before the defence has had time to stop and defend. Momentum The quantity of motion that an object has. Momentum allows gymnasts to swing around the bar when performing on the uneven bars.
