Estimation of spinal loading using inertial motion capture and ground reaction force prediction: A validation study
Authors
Svenningsen, Frederik Petri ; Larsen, Frederik Greve
Term
4. semester
Education
Publication year
2018
Submitted on
2018-06-07
Abstract
Analyse af bevægeapparatet i 3D kræver typisk måling af jordreaktionskræfter og -momenter (GRF&Ms) med gulvmonterede kraftplader samt segmentkinematik med optiske kameraer, som er dyre og upraktiske uden for laboratoriet. Nye bærbare inertielle sensorer (inertial motion capture, IMC) gør det muligt at registrere hele kroppens bevægelser i næsten alle miljøer. Derudover kan nye metoder forudsige GRF&Ms alene ud fra kropskinematik (den målte bevægelse af kropssegmenter). I dette studie undersøgte vi en ny tilgang til at estimere den interne belastning på lændesøjlen udelukkende baseret på IMC som input til en muskuloskeletal model. Vi validerede IMC-modellen ved at sammenligne dens estimater af GRF&Ms og L4–L5 ledreaktionskræfter (kræfter i leddet mellem fjerde og femte lændehvirvel) med en standard laboratoriemodel hos 13 forsøgspersoner under almindelige opgaver med manuel materialehåndtering. Overensstemmelsen blev vurderet med Pearsons korrelationskoefficient, relative og root-mean-square (RMS) fejl samt størrelses- og fasefejl. Resultaterne viste generelt bedst overensstemmelse for vertikale jordreaktionskræfter, sagittale og frontale jordreaktionsmomenter samt for L4–L5 aksial kompression og anteroposteriore forskydningskræfter. Studiet peger på, at belastningen af ryggen kan undersøges i felten ved hjælp af kun IMC og muskuloskeletal modellering.
Three-dimensional analysis of the musculoskeletal system usually relies on measuring ground reaction forces and moments (GRF&Ms) with floor-mounted force plates and tracking segment motion with optical cameras—tools that are costly and inconvenient outside the lab. Recent wearable inertial sensors (inertial motion capture, IMC) enable full-body motion capture in almost any setting. In addition, new methods can predict GRF&Ms from body kinematics alone (the measured movements of body segments). In this study, we investigated a new approach to estimate internal loading on the lumbar spine using only IMC as input to a musculoskeletal model. We validated the IMC-based model by comparing its estimates of GRF&Ms and L4–L5 joint reaction forces (forces at the joint between the fourth and fifth lumbar vertebrae) against a standard laboratory model in 13 participants performing common manual materials handling tasks. Agreement was assessed using Pearson’s correlation coefficient, relative and root-mean-square (RMS) error, and magnitude and phase error. The best agreement was found for vertical ground reaction forces, sagittal and frontal ground reaction moments, and for L4–L5 axial compression and anteroposterior shear forces. These results indicate that spine loading can be investigated in real-world environments using only IMC and musculoskeletal modelling.
[This abstract was generated with the help of AI]
Keywords
Documents