2010 journal article

Comparing polynomial and cubic spline interpolation of segment angles for estimating L5/S1 net moment during symmetric lifting tasks

JOURNAL OF BIOMECHANICS, 43(3), 583–586.

By: X. Xu*, C. Chang*, G. Faber*, I. Kingma* & J. Dennerlein

author keywords: Symmetric lifting; Interpolation; Segment angle; L5/S1 net moment
MeSH headings : Computer Simulation; Humans; Lifting; Lumbar Vertebrae / physiology; Male; Models, Biological; Muscle Contraction / physiology; Muscle, Skeletal / physiology; Numerical Analysis, Computer-Assisted; Reproducibility of Results; Sacrum / physiology; Sensitivity and Specificity; Torque; Weight-Bearing / physiology; Young Adult
TL;DR: C cubic spline interpolation on body segments angles provides a more robust basis for calculating L5/S1 net moment from a few key video frames than polynomial interpolations on joint angles from key frames extracted from video recordings. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

Simple video-based methods previously proposed for field research to estimate L5/S1 net moments during real-world manual materials handling rely on polynomial interpolation on the joint angles from key frames extracted from video recordings; however, polynomial interpolations may not converge as the number of interpolation points increases. Therefore, we compared L5/S1 net moments calculated from continuous kinematic measurements to those calculated from both polynomial and cubic spline interpolation on body segments angles during lifting tasks. For small number of interpolation points (<6) the error in the predicted moment from both the spline and polynomial fits decreased with the increase in the number of interpolation points; however, above 6 interpolation points error for the polynomial fits started to increase while the error from the spline fit continued to decrease. These results suggest that cubic spline interpolation on body segments angles provides a more robust basis for calculating L5/S1 net moment from a few key video frames.