accelerometry

Accelerometry is the measurement of acceleration forces. In practice, accelerometers are small sensors, often based on MEMS technology, that detect changes in velocity and orientation. They can be uniaxial, biaxial, or triaxial, measuring acceleration along one or more orthogonal axes. Outputs are usually given in units of g (1 g equals 9.80665 m/s^2) or directly in meters per second squared, and data are typically sampled at tens to hundreds of hertz.

Most devices combine accelerometers with processing algorithms to separate dynamic movement from gravity. Calibration and filtering are important because gravity can dominate low-frequency signals. Analyses commonly include calculating the vector magnitude from multi-axis data, generating activity counts, and applying algorithms to detect steps, posture, or specific movements. Data are often summarized over time intervals (epochs) and can be synchronized with other sensors for multimodal analyses.

Applications span physical activity monitoring in health research and clinical trials, gait and posture analysis, ergonomics and occupational monitoring, sports science, sleep research, and fall-detection systems. Accelerometry offers continuous, objective measurement in daily life and is applicable in both research and consumer contexts, including smartphones and wearable devices. Limitations include sensitivity to sensor orientation and placement, adherence and wear time, signal noise, and the need for standardized processing to enable comparisons across studies or platforms.

Overall, accelerometry provides a versatile, noninvasive means to quantify movement and acceleration-related phenomena across diverse settings.