Balfany, Katherine

Dawes, Jay

Ducheny, Spencer

Lockie, Robert G.

Moreno, Matthew R.

Orr, Rob Marc

English

An essential job task for military personnel is a casualty drag. A backwardscasualty drag is required when a soldier must drag a colleague from ahazardous environment. The US Army created a simulation that measures thecapacity to perform this task, and involves dragging a 123-kg dummy(equivalent weight to a soldier wearing a combat load) backwards over a 15-mdistance.• In the field, a casualty drag can be demanding, and execution of this task could affect subsequent tasks a soldier may need to perform (e.g. moving underdirect fire). As a result, the ability to perform this task should be developedduring basic training.• Military populations are now using technology more commonly associated withelite sport. Technology has been adopted in an attempt to ensure cadetsexperience the appropriate load to achieve the desired adaptations duringtraining, and to reduce injury occurrence. One example of emergingtechnology that could have practical application in military training, especiallybasic training, is surface electromyography (sEMG) wearable technology.• sEMG wearable technology evaluates muscle activation and recruitment duringphysical activity, and uses this input to measure training load (TL). Themeasurement of TL via wearable technology could provide an indication of thestress placed on the body by the performed activities, and this system couldmeasure tactical tasks such as a casualty drag in a practical environmen

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Bond UniversityResearch RepositoryA Pilot Analysis of Emerging Surface Electromyography Wearable Technology: Training LoadDemands, Muscle Ratios, and Sex Differences in the Casualty DragLockie, Robert G.; Moreno, Matthew R. ; Ducheny, Spencer; Orr, Rob Marc; Dawes, Jay;Balfany, KatherineUnpublished: 11/02/2020Document Version:Peer reviewed versionLink to publication in Bond University research repository.Recommended citation(APA):Lockie, R. G., Moreno, M. R., Ducheny, S., Orr, R. M., Dawes, J., & Balfany, K. (2020). A Pilot Analysis ofEmerging Surface Electromyography Wearable Technology: Training Load Demands, Muscle Ratios, and SexDifferences in the Casualty Drag. Poster session presented at 5th International Congress on Soldiers' PhysicalPerformance, Quebec, Canada.General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.For more information, or if you believe that this document breaches copyright, please contact the Bond University research repositorycoordinator.Download date: 12 Apr 2020Robert G. Lockie1  Matthew R. Moreno1  Spencer C. Ducheny1  Robin M. Orr2  J. Jay Dawes3  Katherine Balfany4,51Center for Sport Performance, Department of Kinesiology, California State University, Fullerton, Fullerton, CA, USA. 2Tactical Research Unit, Bond University, Robina, Qld, Australia.3School of Kinesiology, Applied Health and Recreation, Oklahoma State University, Stillwater, OK, USA.4Athos, DBA. Mad Apparel, Redwood City, CA, USA.5Department of Physical Medicine and Rehabilitation, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA. A Pilot Analysis of Emerging Surface Electromyography Wearable Technology: Training Load Demands, Muscle Ratios, and Sex Differences in the Casualty DragINTRODUCTIONMETHODSCONCLUSIONSRESULTS• The descriptive data for males and females are shown in Table 1. Males weresignificantly taller and heavier, and completed the CD faster than the females (all p< 0.01). Accordingly, females experienced a greater TL for the QUAD, HAM, GM,and total (all p < 0.01). There were no between-sex differences in the muscle ratios(p = 0.56-0.64).• The sEMG wearable technology could indicate the stress associated with soldieringtasks, in this instance a backwards casualty drag. Slower performance increased TLdemands, which was notable for the females. This could impact other activitieswhich could also result in high TL demands, such as moving to cover, where soldierswill need to sprint and move into different positions (e.g. kneeling or pronepositions) (2). Greater QUAD contribution in the casualty drag, shown through theQUAD-HAM ratio, could contribute to faster performance.• This study provided a pilot analysis into how emerging sEMG wearable technologycould be used to measure military tasks, and by extension potentially integratedinto basic training. The current data detailed that less-efficient performance of thedragging task was related to higher TL demands. This has implications for soldiertraining, where TL increases have been associated with injury risk. sEMG wearabletechnology could be used to measure the stress of tasks where TL metrics may bedifficult to measure (e.g., lifting and carrying loads, combat simulations).• Nonetheless, there is still a need for greater research into the validity and reliabilityof the sEMG wearable technology. This needs to be conducted prior to any furtheruse in military populations.• The sensors provided a bipolar differential sEMG measurement with an inter-electrode distance of 2.1 cm and were comprised of a conductive polymer. No skinor electrode preparation was performed at the site for each electrode as it alignedwith recommended product usage.• After a dynamic warm-up, participants completed maximum voluntary isometriccontraction (MVIC) assessments via manual muscle testing for each leg which wasused to normalize the sEMG data (1). Participants then performed two trials of a123-kg casualty drag over 15-m (2). A 91-kg dummy with a 32-kg weighted vestwas positioned on the ground, and participants grabbed the vest handles anddragged the dummy backwards over the required distance as quickly as possible.Time was recorded via stopwatch to calculate drag velocity (measured in metersper second; m/s), with the fastest trial analyzed.• The sEMG signal for each muscle was measured as a percentage of MVIC tocalculate TL (measured in arbitrary units; AU). The variables included: overall TL(sum of all muscles), and QUAD:HAM, GM:HAM, and QUAD:HAM+GM ratios.Independent samples t-tests calculated sex differences between CD velocity andthe sEMG variables. Partial correlations controlling for sex calculated relationshipsbetween CD velocity and the sEMG variables.References1. Balfany K, Chan MS, Lockie RG, Lynn SK. Sports performance wearable technology, sEMG and manual muscle testing: Practical methods for measuring maximal voluntary contractions. In: Proceedings of the American Colllege of SportsMedicine Annual Meeting. 2019: Orlando, FL.2. Foulis, SA, Redmond, JE, Frykman, PN, Warr, BJ, Zambraski, EJ, and Sharp, MA. U.S. Army physical demands study: Reliability of simulations of physically demanding tasks performed by combat arms soldiers. J Strength Cond Res 31: 3245-3252, 2017.3. Friedl, KE. Military applications of soldier physiological monitoring. J Sci Med Sport 21: 1147-1153, 2018.4. Jones, BH, Hauschild, VD, and Canham-Chervak, M. Musculoskeletal training injury prevention in the U.S. Army: Evolution of the science and the public health approach. J Sci Med Sport 21: 1139-1146, 2018.5. Jones, CM, Griffiths, PC, and Mellalieu, SD. Training load and fatigue marker associations with injury and illness: A systematic review of longitudinal studies. Sports Med 47: 943-974, 2017.6. Lockie, RG, Balfany, K, Denamur, JK, and Moreno, MR. A preliminary analysis of relationships between a 1RM hexagonal bar load and peak power with the tactical task of a body drag. J Hum Kinet 68: 157-166, 2019.7. Lynn, SK, Watkins, CM, Wong, MA, Balfany, K, and Feeney, DF. Validity and reliability of surface electromyography measurements from a wearable athlete performance system. J Sports Sci Med 17: 205-215, 2018.8. Stevenson, RD, Siddall, AG, Turner, PF, and Bilzon, JL. Physical employment standards for UK firefighters: Minimum muscular strength and endurance requirements. J Occup Environ Med 59: 74-79, 2017.• An essential job task for military personnel is a casualty drag. A backwardscasualty drag is required when a soldier must drag a colleague from ahazardous environment. The US Army created a simulation that measures thecapacity to perform this task, and involves dragging a 123-kg dummy(equivalent weight to a soldier wearing a combat load) backwards over a 15-mdistance (2).• In the field, a casualty drag can be demanding, and execution of this task couldaffect subsequent tasks a soldier may need to perform (e.g. moving underdirect fire). As a result, the ability to perform this task should be developedduring basic training.• Military populations are now using technology more commonly associated withelite sport (3). Technology has been adopted in an attempt to ensure cadetsexperience the appropriate load to achieve the desired adaptations duringtraining, and to reduce injury occurrence (4). One example of emergingtechnology that could have practical application in military training, especiallybasic training, is surface electromyography (sEMG) wearable technology.• sEMG wearable technology evaluates muscle activation and recruitment duringphysical activity, and uses this input to measure training load (TL) (7). Themeasurement of TL via wearable technology could provide an indication of thestress placed on the body by the performed activities (5), and this system couldmeasure tactical tasks such as a casualty drag in a practical environment.PURPOSETable 2. Correlation data for casualty drag velocity with the TL variables measured by the sEMG wearabletechnology.Table 1. Descriptive data (mean ± SD) for casualty drag velocity and the TL variables measured by the sEMGwearable technology.Males (n = 25) Females (n = 11)Age (years) 25.16 ± 3.87 24.73 ± 3.13Height (m) 1.78 ± 0.09 1.66 ± 0.08*Body Mass (kg) 88.93 ± 21.59 67.86 ± 8.58* Casualty Drag Velocity (m/s) 1.49 ± 0.26 0.83 ± 0.16*QUAD TL (AU) 27.23 ± 9.65 44.37 ± 14.82*HAM TL (AU) 16.82 ± 8.03 29.54 ± 11.27*GM TL (AU) 11.96 ± 4.32 20.82 ± 7.34*Total TL (AU) 56.01 ± 15.30 94.73 ± 27.84*QUAD:HAM 1.07 ± 0.80 0.92 ± 0.58GM:HAM 0.88 ± 0.58 0.76 ± 0.32QUAD:HAM+GM 0.97 ± 0.40 0.91 ± 0.25QUAD TL HAM TL GM TL Total TL QUAD:HAM GM:HAMQUAD:HAM+GMVelocity rp-0.64*<0.01-0.280.10-0.310.07-0.59*<0.01-0.35*0.04-0.220.20-0.260.13* Significant (p < 0.05) relationship between casualty drag velocity and the TL variable.• The purpose of this study was to determine TL demands, muscle ratios, and sexdifferences in the tactical task of a casualty drag (CD) using sEMG wearabletechnology.• A convenience sample of 36 college-aged participants (age = 25.03 ± 3.62years; height = 1.74 ± 0.10 m; body mass = 82.49 ± 20.92 kg), including 25males and 11 females, volunteered to participate in this research. Physicallyactive, healthy volunteers were used as surrogates for a tactical population, asthis allowed for recruitment of males and females with divergent physicalcapabilities (6,8). Previous research has shown minimal learning effects withthe casualty drag (2), which means that even for participants who were notsoldiers, they should perform the casualty drag with consistency across trials.• Participants were fitted with sEMG wearable technology (Athos, Redwood City,California) prior to testing. Males wore compression shorts, females woreleggings, and each were embedded with sEMG sensors that measured thevastus medialis and lateralis (quadriceps; QUAD), biceps femoris (hamstrings;HAM), and gluteus maximus (GM) of both legs.OPERATIONAL RELEVANCE• This study provided a pilot investigation into how sEMG wearable technology couldbe integrated into basic training by measuring TL of a specific task. Initial measuresindicated greater TL demands with slower CD task performance.• sEMG wearable technology could measure soldier TL during basic training, withobjectives of enhancing performance and decreasing injury risk via workloadmonitoring and manipulation. However, more research is required to validate thesEMG wearable technology to ensure accuracy of data.* Significantly (p < 0.05) different from the males.ACKNOWLEDGMENTS• The sEMG-based wearable technology was provided by Athos. Author KatherineBalfany consulted with the wearable technology company.• A slower drag velocity correlated with agreater overall TL for both sexes, inaddition to a greater QUAD TL (Table 2).There was a significant correlationbetween faster CD velocity and greaterQUAD-HAM ratio

A Pilot Analysis of Emerging Surface Electromyography Wearable Technology: Training Load Demands, Muscle Ratios, and Sex Differences in the Casualty Drag

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A Pilot Analysis of Emerging Surface Electromyography Wearable Technology: Training Load Demands, Muscle Ratios, and Sex Differences in the Casualty Drag

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