Revision session info

an object either remains at rest or continues to move with constant momentum, unless acted upon by a net force

the rate of change of momentum of a body is proportional to the force causing it and the change takes place in the direction in which the force acts

the conceptual point where all the mass of a body can be considered to be concentrated

for every action force there is a reaction force which is equal in magnitude but opposite in direction “every action has an equal and opposite reaction”

Up and down

Left and right

Front & Back

average gradient between 20-80% of impact peak

maximum gradient before impact peak

accurate and reliable 3D force measurements high sampling frequency and resolution

often restricted to indoor use and a single step possibly unnatural gait (force plate targeting)

Splitting motion into vertical and horizontal components

Portable force monitors can be used outside of a lab setting, making them more versatile. They provide a good alternative when fixed force plates are not available or practical.

Typically, they are less accurate and reliable compared to lab-based force plates. Often only measure vertical forces. May not be embedded into the ground, which can affect the accuracy of certain movements (e.g., running over a raised surface).

measures instantaneous acceleration at rest will measure 1g due to gravity orientation is important

Can be cheaper and easier to use compared to other force measurement tools. Often embedded within other devices such as GPS units, making them multifunctional. Measure acceleration in three dimensions (x, y, and z axes), providing comprehensive data on movement.

Placement: The position where the accelerometer is placed on the body or equipment can affect the measurements. For example, a GPS unit with an embedded accelerometer might not accurately represent the centre of mass. Movement Influence: The presence of the device should not interfere with the natural movement of the subject. Battery Life and Comfort: Ensure the device has sufficient battery life for the duration of the measurement and is comfortable for the user to wear.

cheaper than lab equipment easy to use often embedded within other devices can monitor closer to the site of interest

valid for intended purpose? affect the movement being monitored? battery life,

Frame Rate Definition: The number of frames (or images) captured per second in a video. Units: Typically measured in frames per second (fps) or Hertz (Hz). Shutter Speed Definition: The length of time the camera’s shutter is open to expose light onto the camera sensor for each frame. Units: Typically measured in fractions of a second (e.g., 1/50 s, 1/1000 s).

Definition: The distance between the camera lens and the image sensor when the subject is in focus.

Wide-angle view, captures more of the scene, often used for landscapes.

Narrow field of view, magnifies distant subjects, often used for wildlife or sports photography.

The range of distance within a photo that appears acceptably sharp and in focus.