Inertial measurement unit-based pose estimation: Analyzing and reducing sensitivity to sensor placement and body measures.

Introduction: Inertial measurement units have been proposed for automated pose estimation and exercise monitoring in clinical settings. However, many existing methods assume an extensive calibration procedure, which may not be realizable in clinical practice. In this study, an inertial measurement unit-based pose estimation method using extended Kalman filter and kinematic chain modeling is adapted for lower body pose estimation during clinical mobility tests such as the single leg squat, and the sensitivity to parameter calibration is investigated.

Automated Assessment of Dynamic Knee Valgus and Risk of Knee Injury During the Single Leg Squat.

Many clinical assessment protocols of the lower limb rely on the evaluation of functional movement tests such as the single leg squat (SLS), which are often assessed visually. Visual assessment is subjective and depends on the experience of the clinician. In this paper, an inertial measurement unit (IMU)-based method for automated assessment of squat quality is proposed to provide clinicians with a quantitative measure of SLS performance.

Classification of squat quality with inertial measurement units in the single leg squat mobility test.

Many assessment and diagnosis protocols in rehabilitation, orthopedic surgery and sports medicine rely on mobility tests like the Single Leg Squat (SLS). In this study, a set of three Inertial Measurement Units (IMUs) were used to estimate the joint pose during SLS and to classify the SLS as poor, moderate or good. An Extended Kalman Filter pose estimation method was used to estimate kinematic joint variables, and time domain features were generated based on these variables.

A single video camera postural assessment system to measure rotation of the shoulder during computer use.

The goal of this study was to evaluate the performance of a single video camera system for measuring shoulder rotation during computer work, and to quantify the work and postural space within which the system performs optimally. Shoulder rotation angles calculated using the video system were compared with angles calculated using an active infrared LED three-dimensional motion analysis system while 10 adult volunteers simulated postures for two different trials: typical of normal computer work (freestyle) and with forced shoulder abduction (constrained). Average and absolute errors were calculated to determine the accuracy and precision of the system, respectively, for each trial, for each position, and for both the right and left hands.

The influence of job rotation and task order on muscle fatigue: a deltoid example.

Despite frequent use in industry, job rotation lacks robust confirmation as an effective method to limit exposure. This study investigated two tasks that involved the deltoid muscle. We examined two major factors in the context of muscle fatigue: the presence of rotation between tasks, and the order of task rotation if rotation was present.