A data set with kinematic and ground reaction forces of human balance

Abstract

This article describes a public data set with the three-dimensional kinematics of the whole body and the ground reaction forces (with a dual force platform setup) of subjects standing still for 60 s in different conditions, in which the vision and the standing surface were manipulated. Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with metadata has information about each subject's sociocultural, This article describes a public data set with the three-dimensional kinematics of the whole 15 body and the ground reaction forces (with a dual force platform setup) of subjects standing still 16 for 60 s in different conditions, in which the vision and the standing surface were manipulated.17 Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file 18 with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 19 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with 20 metadata has information about each subject's sociocultural, demographic, and health

Direct estimation of the parameters of a delayed, intermittent activation feedback model of postural sway during quiet standing

“…The IPC model was fit to empirical postural control data to 1) estimate the multivariate distributions of each parameter, 2) test for expected effects from age and visual feedback, 3) test the consistency of parameters within-person, 4) compare the proposed model to simpler alternatives. COM data were obtained from the data set published for public use by Santos et al [20] and included 49 individuals at 100Hz for 60 seconds per trial. Three trials were conducted with eyes open, and three with eyes closed.…”

“…Estimates of both process noise and measurement error were very close to their true values in every case, with only small upward bias proportional to the magnitude of the estimate for certain parameter sets (Figs 3 and 4). The standard deviation of measurement error that we chose to simulate was σ = .01 cm, twenty times the error of the force plate used by Santos et al [20] to obtain the data. The success of estimation despite greatly exaggerated sensor noise demonstrates the reliability of Kalman filtering and adequate technical specification of the model, and relieves researchers from the need to choose a preliminary noise reduction step such as spectral filtering.…”

“…To test the precision and accuracy of IPC parameter estimates given the dimensions and expected structure of the data from Santos et al [20], one-hundred individuals were simulated for each parameter set in Table 3, with examples series shown in Fig 2. Each individual consisted of three trials, and each trial consisted of a 60s series downsampled to 100 Hz.…”

“…Validation of this analytic strategy will set a foundation for estimating the parameters of alternative models and more comprehensive comparisons. Following the validation study, we estimated empirical values of each parameter from publicly available COM data [20] and compared our results with theoretically expected values from the literature. We included two previously demonstrated covariates in our analysis, visual feedback and age, to attempt to replicate previous findings as further evidence for the validity of the model.…”

Peer Review #2 of "Acute effects of contract-relax proprioceptive neuromuscular facilitation stretching of hip abductors and adductors on dynamic balance (v0.1)"

“…Postural control is the output of muscle activity that counteracts the destabilizing effects of gravity and inertia in static and dynamic conditions (Duarte & Sternad, 2008). The ability to maintain balance is based on multiple components that coordinate sensory input and motor output (Li et al, 2018;Dos Santos et al, 2017;Stins et al, 2011;Manor et al, 2010). Due to differences in postural control schemes, the convention has classified balance as either static or dynamic.…”