Muscle Activity during Postural Stability Tasks: Role of Military Footwear and Load Carriage
Sachini N.K. Kodithuwakku Arachchige,
Harish Chander,
Alana J. Turner,
Samuel J. Wilson,
Jeffrey D. Simpson,
Adam C. Knight,
Reuben F. Burch V.,
Chip Wade,
John C. Garner,
Daniel Carruth
Affiliations
Sachini N.K. Kodithuwakku Arachchige
Neuromechanics Laboratory, Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA
Harish Chander
Neuromechanics Laboratory, Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA
Alana J. Turner
Neuromechanics Laboratory, Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA
Samuel J. Wilson
Department of Health Sciences and Kinesiology, Georgia Southern University, Statesboro, GA 30460, USA
Jeffrey D. Simpson
Sports Medicine & Neuromechanics Laboratory, Department of Movement Sciences & Health, University of West Florida, Pensacola, FL 32514, USA
Adam C. Knight
Neuromechanics Laboratory, Department of Kinesiology, Mississippi State University, Mississippi State, MS 39762, USA
Reuben F. Burch V.
Department of Human Factors & Athlete Engineering, Center for Advanced Vehicular Systems (CAVS), Mississippi State University, Mississippi State, MS 39762, USA
Chip Wade
Department of Industrial and Systems Engineering, Auburn University, Auburn, AL 36849, USA
John C. Garner
Department of Health and Kinesiology, Troy University, Troy, AL 36082, USA
Daniel Carruth
Department of Human Factors & Athlete Engineering, Center for Advanced Vehicular Systems (CAVS), Mississippi State University, Mississippi State, MS 39762, USA
Decrements to postural control manifest as an increase in muscle activity, indicating continuous attempts to maintain body equilibrium and postural stability. Extrinsic factors such as footwear, and intrinsic factors such as muscle fatigue, can affect postural stability. The purpose of this study was to analyze the impact of two types of military footwear and a military-type load-carrying task on lower extremity muscle activity during various postural stability tasks. Sixteen males’ (age: 26.63 ± 3.93 years; mass: 87 ± 12.4 kg; height: 178.04 ± 6.2 cm) muscle activity from knee flexors, extensors, ankle dorsiflexors, and plantar flexors were measured using electromyography in standard (STD) and minimalist (MIN) military footwear, before (PRE) and after (POST) a simulated workload during sensory organization and motor control tests on the Neurocom EquitestTM. Mean muscle activity was analyzed using 2 (footwear) × 2 (time) repeated measures ANOVA with an alpha level of 0.05. Results revealed a requirement of significantly greater muscle activity in POST and STD. MIN demonstrated lesser balance decrements POST workload, which could be attributed to its design characteristics. Results will help in suggesting footwear design characteristics to minimize muscular exertion while eliciting better postural control, and to prevent postural instability due to overexertion in military personnel.
