Work Description

Research Overview � This research was conducted by Payam Mirshams Shahshahani, Mariana Masteling, and James A. Ashton-Miller. Unipedal stance time is a significant predictor of fall risk in middle- and older-aged individuals. Because muscle fatigue reduces muscle strength over a sustained contraction, muscle endurance time could limit maximum unipedal stance time. 18 healthy young (10 females) and 17 older (10 females) adults who could stand on one leg for at least 10 s were recruited for this project. Using a non-weight bearing test, left hip isometric maximum abduction strength and endurance time at 50% of that strength was measured. Subjects� maximum unipedal stance time, while force plate and full-body 3D motion capture signals were recorded. Subject-specific inverse dynamics biomechanical models were used to calculate the hip abduction moment required to stand on one leg. The files in this dataset are to support the findings in our paper in the IISE Transactions on Occupational Ergonomics and Human Factors Journal (�A non-weight bearing method for measuring hip abduction strength overestimates hip abductor muscle fatigue during one-leg stance''). This research was part of the dissertation of Payam Mirshams Shahshahani in his PhD from 2013 to 2019. He did his PhD in the Biomechanics Research Lab at the Mechanical Engineering Department at the University of Michigan Ann Arbor. The funding for this work was provided by NIH the details of which can be found in the manuscript. Methods � Details can be seen in the Methods section of the manuscript and the supplementary information. R was used to analyze the statistical relationships between measured hip strength, measured hip endurance time, and estimated hip abduction moment used during one-leg balance. File Inventory � OLB QS Hip Torque3.csv: Biomechanics lab recordings of subjects standing on one leg for up to 4 minutes included force plate and full body motion capture data. The data was analyzed by the in-lab software to provide aggregate kinematic and inverse dynamics estimates for parameters related to standing on one leg. This file contains the tabulated aggregate data to be analyzed statistically with R. OLB_Parameters6.csv: A table containing the anthropometric characteristics of the subjects of the study including gender, height, weight, and mass link estimations based on literature. csvCode_20231223.R: The code used for joining the separate tables into an R dataset. QSHipDataset20231223.RData: R dataset created by joining the contents of the previous 2 tables together used by the R code for analysis. QSAnalysis_20231223.R: Main body of the statistical code that was used for the analyses of the journal article and the figures. Definition of Terms and Variables � Please refer to the manuscript for a full list of terms and variables. Use and Access � Download QSHipDataset20231223.RData and QSAnalysis_20231223.R and use the .R file to run the analysis. Informed consent � All subjects in the study read and signed a consent form (HUM00130970) before participating in the study.