Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel

The loadsol<sup>®</sup> wireless in-shoe force sensors can be useful for in-field measurements. However, its accuracy is unknown in the military context, whereby soldiers have to carry heavy loads and walk in military boots. The purpose of this study was to establish the validity of the...

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Main Authors: Pui Wah Kong, Muhammad Nur Shahril Iskandar, Ang Hong Koh, Mei Yee Mavis Ho, Cheryl Xue Er Lim
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/23/14/6465
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author Pui Wah Kong
Muhammad Nur Shahril Iskandar
Ang Hong Koh
Mei Yee Mavis Ho
Cheryl Xue Er Lim
author_facet Pui Wah Kong
Muhammad Nur Shahril Iskandar
Ang Hong Koh
Mei Yee Mavis Ho
Cheryl Xue Er Lim
author_sort Pui Wah Kong
collection DOAJ
description The loadsol<sup>®</sup> wireless in-shoe force sensors can be useful for in-field measurements. However, its accuracy is unknown in the military context, whereby soldiers have to carry heavy loads and walk in military boots. The purpose of this study was to establish the validity of the loadsol<sup>®</sup> sensors in military personnel during loaded walking on flat, inclined and declined surfaces. Full-time Singapore Armed Forces (SAF) personnel (<i>n</i> = 8) walked on an instrumented treadmill on flat, 10° inclined, and 10° declined gradients while carrying heavy loads (25 kg and 35 kg). Normal ground reaction forces (GRF), perpendicular to the contact surface, were simultaneously measured using both the loadsol<sup>®</sup> sensors inserted in the military boots and the Bertec instrumented treadmill as the gold standard. A total of eight variables of interest were compared between loadsol<sup>®</sup> and treadmill, including four kinetic (impact peak force, active peak force, impulse, loading rate) and four spatiotemporal (stance time, stride time, cadence, step length) variables. Validity was assessed using Bland–Altman plots and 95% Limits of Agreement (LoA). Bias was calculated as the mean difference between the values obtained from loadsol<sup>®</sup> and the instrumented treadmill. Results showed similar force-time profiles between loadsol<sup>®</sup> sensors and the instrumented treadmill. The bias of most variables was generally low, with a narrow range of LoA. The high accuracy and good agreement with standard laboratory equipment suggest that the loadsol<sup>®</sup> system is a valid tool for measuring normal GRF during walking in military boots under heavy load carriage.
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spelling doaj.art-d61346081dd54e108cf719c199c946002023-11-18T21:18:10ZengMDPI AGSensors1424-82202023-07-012314646510.3390/s23146465Validation of In-Shoe Force Sensors during Loaded Walking in Military PersonnelPui Wah Kong0Muhammad Nur Shahril Iskandar1Ang Hong Koh2Mei Yee Mavis Ho3Cheryl Xue Er Lim4Physical Education and Sports Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore 637616, SingaporePhysical Education and Sports Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore 637616, SingaporePhysical Education and Sports Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore 637616, SingaporePhysical Education and Sports Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore 637616, SingaporeCentre of Excellence for Soldier Performance, Singapore Armed Forces, Singapore 637901, SingaporeThe loadsol<sup>®</sup> wireless in-shoe force sensors can be useful for in-field measurements. However, its accuracy is unknown in the military context, whereby soldiers have to carry heavy loads and walk in military boots. The purpose of this study was to establish the validity of the loadsol<sup>®</sup> sensors in military personnel during loaded walking on flat, inclined and declined surfaces. Full-time Singapore Armed Forces (SAF) personnel (<i>n</i> = 8) walked on an instrumented treadmill on flat, 10° inclined, and 10° declined gradients while carrying heavy loads (25 kg and 35 kg). Normal ground reaction forces (GRF), perpendicular to the contact surface, were simultaneously measured using both the loadsol<sup>®</sup> sensors inserted in the military boots and the Bertec instrumented treadmill as the gold standard. A total of eight variables of interest were compared between loadsol<sup>®</sup> and treadmill, including four kinetic (impact peak force, active peak force, impulse, loading rate) and four spatiotemporal (stance time, stride time, cadence, step length) variables. Validity was assessed using Bland–Altman plots and 95% Limits of Agreement (LoA). Bias was calculated as the mean difference between the values obtained from loadsol<sup>®</sup> and the instrumented treadmill. Results showed similar force-time profiles between loadsol<sup>®</sup> sensors and the instrumented treadmill. The bias of most variables was generally low, with a narrow range of LoA. The high accuracy and good agreement with standard laboratory equipment suggest that the loadsol<sup>®</sup> system is a valid tool for measuring normal GRF during walking in military boots under heavy load carriage.https://www.mdpi.com/1424-8220/23/14/6465loadsol<sup>®</sup>gaitground reaction forceload carriageinclineddeclined
spellingShingle Pui Wah Kong
Muhammad Nur Shahril Iskandar
Ang Hong Koh
Mei Yee Mavis Ho
Cheryl Xue Er Lim
Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
Sensors
loadsol<sup>®</sup>
gait
ground reaction force
load carriage
inclined
declined
title Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
title_full Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
title_fullStr Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
title_full_unstemmed Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
title_short Validation of In-Shoe Force Sensors during Loaded Walking in Military Personnel
title_sort validation of in shoe force sensors during loaded walking in military personnel
topic loadsol<sup>®</sup>
gait
ground reaction force
load carriage
inclined
declined
url https://www.mdpi.com/1424-8220/23/14/6465
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AT anghongkoh validationofinshoeforcesensorsduringloadedwalkinginmilitarypersonnel
AT meiyeemavisho validationofinshoeforcesensorsduringloadedwalkinginmilitarypersonnel
AT cherylxueerlim validationofinshoeforcesensorsduringloadedwalkinginmilitarypersonnel