Validation of a motion capture system for deriving accurate ground reaction forces without a force plate

Abstract

Background: Human movement such as physical work, exercise and sport activities can be analyzed to determine kinetic (force) and kinematic (motion) characteristics. In the past, proper assessment of force variables requires force plates that can limit the types of activities performed. Additionally, large amounts of data are often generated, requiring often tedious and time-consuming analyses and calculations. Therefore, the purpose of this project was to compare the vertical ground reaction forces obtained from a force plate with calculated GRFs derived from a motion capture system during body weight squats for five healthy men. Results: After performing three body weight squats, vertical ground reaction forces in Newtons were calculated for each data point for the force plate and motion capture system data, and synchronized from the point of peak force. There were no significant differences (p < .05) for peak force, lowest force, or mean force between trials or modalities (force plate or motion capture system). Comparison of force-time curves with regression analyses indicated excellent agreement between testing modalities (r = 0.995, r 2 = 0.989, SEM = 11.1 N).

Accuracy of Markerless 3D Motion Capture Evaluation to Differentiate between On/Off Status in Parkinson’s Disease after Deep Brain Stimulation

“…The utility of markerless techniques in the evaluation of movement disorders in a clinical setting is controversial because analysis parameters have not been standardized yet. However, several studies have described precise acquisition of human anatomy and consistency with recommendations of biomechanical societies [ 1 , 3 , 5 – 7 , 9 , 10 ].…”

“…These require frequent calibration and restrict the subject's movement to a limited area. The DARI's kinetic capture system does not require force plates and can measure joint torques, ground reaction forces, and other measurements without restricting the subject's natural movement [ 3 ].…”

“…In another study, Perrott concluded that when comparing marker-based versus markerless evaluations, they both report statistically similar ranges of change in the angle of squats in pelvis and lower limbs [ 9 ]. These findings illustrate that a 3D markerless motion capture is a highly repeatable system which can have a variety of new applications for athletic and healthcare settings [ 3 – 7 , 9 ]. However, there is currently no gold-standard for motion capture systems and the results are not always consistent because they vary from device to device.…”

Precision strength training: Data-driven artificial intelligence approach to strength and conditioning

“…Easily acquired continuous measurements are not always helpful when the signal has lowdelity, or when the data is not the most relevant for the task in question [113]. [607], testosterone assay for both acute exercise-induced response and global levels [288,484], muscle oxygenation with fNIRS [679], ultrasound SWE for the (real-time) quantication of musculotendon stiness [419,467], cartoon of smart insoles for quantifying center-of-pressure (CoP) and the tripod loading , force plates for measuring ground reaction forces [245], EMG for measuring activation [257] (myoelectric activity more exactly [841]), sweat-based biochemical sensing for detecting metabolic and neuromuscular fatigue from ammonia and lactate levels [697], core body temperature for circadian phase [788] and muscle temperature measurements for training preparedness, subjective rating of eort through RPE logging (https://www.reactivetrainingsystems.com/), cognitive load from electrical (EEG) [396] and hemodynamic (fNIRS) brain activity [395]. Image from Dr. Ben Pollock, reproduced with permission.…”

An Analysis of In Vivo Hip Kinematics in Elite Baseball Batters Using a Markerless Motion-Capture System

“…15 This technology has proven more consistent with repetitive testing and is being more frequently applied in the field of sports medicine for athletes' rehabilitation and injury prevention. 14,[16][17][18][19] The purpose of this study was to investigate the kinematics of the asymptomatic baseball batter's hips by comparing passive range of motion (PROM) and realtime active hip range of motion (AROM) and determine whether differences in ROM exist between lead and trail hips. It is hypothesized that active ROM during the batting swing would approach the maximal passive ROM, particularly for lead hip external rotation during the explosive acceleration phase of the swing.…”