week 2

Vocabulary flashcards covering key terms from the biomechanics lecture notes on force measurement, data acquisition, sensors, and related concepts.

Signal type

The category of data being measured (e.g., analogue vs digital inputs; examples include strain, temperature, force, voltage).

Calibration

Process of relating sensor output (e.g., voltage) to known input values to convert measurements into physical units.

Data acquisition

The overall process of collecting sensor data, including sensing, transfer, and recording via software.

I/O (Input/Output)

Interfaces used to transfer data between sensors and the computer system (e.g., cables, modems, wireless, Bluetooth).

Transfer the signal

Moving data from the sensor to the data acquisition system for processing.

Software programming (data acquisition)

Creating software to capture, display, and process data or to control instruments during data collection.

Strain

Deformation per unit length in a material caused by applied load.

Strain gauge

A sensor whose electrical resistance changes with strain, used to measure deformation.

Electrical resistance gauge

A type of strain sensor that infers strain from resistance changes.

Force plate

A platform with embedded sensors (piezoelectric or strain gauges) to measure ground reaction forces.

Piezoelectric sensor

A sensor that generates voltage when stressed, used for dynamic force measurements.

Force plate (strain gauge)

A force plate that uses strain gauges to measure forces, with typically lower drift but potential temperature sensitivity.

Accelerometer

Sensor that measures acceleration; can directly measure acceleration or infer force via F = ma.

Isokinetic dynamometer

Device that maintains constant joint angular velocity to measure muscle torque.

Torque

Rotational force around a joint.

Concentric torque

Torque produced during muscle shortening.

Eccentric torque

Torque produced during muscle lengthening.

Isometric torque

Torque produced with no movement at the joint (static contraction).

Isotonic torque

Torque under approximately constant resistance during movement.

Center of Pressure (CoP)

The location of the resultant ground reaction force in the plane of the force plate.

Ground reaction force (GRF)

The force exerted by the ground on the body during movement.

Inertial Measurement Unit (IMU)

A device combining accelerometer, gyroscope, and magnetometer to estimate motion and orientation.

MEMS

Micro-Electro-Mechanical Systems; technology used in small sensors like accelerometers and gyroscopes.

Gyroscope

Sensor that detects angular velocity and rotation/orientation changes.

Magnetometer

Sensor measuring magnetic fields to aid orientation estimation.

F-scan (Tekscan)

Pressure measurement system using resistive sensor arrays to map plantar pressure.

Analogue-to-digital converter (ADC)

Device that converts continuous analogue signals into discrete digital values for processing.

Analogue input

Continuous signals such as temperature, pressure, strain, voltage, or force.

Digital input

Discrete signals such as TTL-level pulses used in digital systems.

Sonic measurement

Distance measurement using the travel time of sound waves.

Electromagnetic measurement

Displacement/position measurement using electromagnetic waves (e.g., Fastrak, Flock of Birds).

Radar measurement

Displacement/velocity measurement using radar Doppler effects.

Potentiometers

Devices that convert angular position into an electrical signal.

Rotary encoders

Sensors translating rotation into digital signals to track angular displacement.

Gravity compensation

Correcting measurements for the influence of gravity (important in dynamometry).

Axis of rotation

The axis around which a joint rotates; alignment is critical for accurate torque measurements.

Pressure

Force per unit area; used in pressure measurement systems.

Pressure transducer

Sensor converting pressure into an electrical signal.

2D COP coordinates (Ax, Ay)

The two coordinates used to locate the CoP on a force plate.

CoP trace

The time-varying path of the center of pressure across a trial.

Acoustic measurement

Distance or motion measurement using sound-based methods.

Optical measurement

Kinematic measurement using video or optical tracking methods.

Intensity of data acquisition methods (modems/WiFi/Bluetooth)

Ways to transmit data from sensors to processing systems, including wired and wireless options.