Prof. Anne Silverman is collaborating with Naval Health Research Center (NHRC) on a new award from the Department of Defense as part of their Military Operational Medicine Research Program (MOMRP). This award builds on Silverman’s previous work with NHRC to assess the risk of musculoskeletal injuries among military service members related to walking with heavy backpack loads.
Fig.1: Musculoskeletal model and walking simulation of military load carriage (developed in OpenSim v. 3.3). The model contains detailed musculature in the lower limbs and lumbar spine. The newly funded project will support individualization of muscle strength capability and associated injury risk factors during dynamic movements.
Ruck marching is a biomechanically demanding activity commonly associated with injury occurrence in the military. Walking with backpack loads increases muscle and joint contact forces, which can lead to overuse injury – and injuries affect military readiness. Injury rates are higher for women than for men in the military, which may be partially attributable to differences in muscle strength and variations in muscle strength across joints.
Silverman suggests that the risk of injury can be mitigated with training and gear recommendations that are informed by an understanding of the relationship between muscle strength and injury risk factors.
Silverman’s research team, including mechanical engineering PhD candidate Jordan Sturdy, has already developed a musculoskeletal model to simulate walking with backpack load carriage to investigate biomechanical injury mechanisms related to backpack design. The results were recently published in Applied Ergonomics (https://doi.org/10.1016/j.apergo.2020.103277).
With this new project, entitled “Individualized Injury Risk Assessment Using Warfighter Specific Modeling: Implications for Training,” Silverman’s team will receive approximately $600,000 over three years to improve musculoskeletal model predictions to more accurately assess individual injury risks related to specific load carriage configurations and levels of muscle strength.
“This is a large component of our ongoing collaboration with the Warfighter Performance Department at Naval Health Research Center,” said Silverman. “This new award will enable us to translate musculoskeletal modeling results to inform training plans and rigorously investigate the effects of muscle strength on injury. This award is very exciting for our group!”
The team’s goal for the new program is to improve musculoskeletal model predictions by incorporating individual measurements of joint strength and body segment mass distribution. With these additional measurements, a strength scaling framework will be applied to develop individualized models that represent the unique differences in strength distribution among study participants. The models will be used to quantify various forces from movement simulations of loaded walking on slopes. The team will also determine the effect of hip and lumbar strength levels on biomechanical injury risk factors during loaded walking.
Fig. 2: Detail of the military backpack attachment model from J.T. Sturdy et al., “A backpack load sharing model to evaluate lumbar and hip joint contact forces during shoulder borne and hip belt assisted load carriage,” Applied Ergonomics 90:103277, https://doi.org/10.1016/j.apergo.2020.103277.
The team’s investigations will inform benchmarks for joint strength and associated training recommendations. Silverman’s work in this program supports the MOMRP mission to “develop effective biomedical countermeasures against operational stressors and to prevent physical and psychological injuries during training and operations in order to maximize the health, readiness and performance of Service members and their Families.” (https://momrp.amedd.army.mil/).
Anne Silverman is the Rowlinson Associate Professor of Mechanical Engineering at Colorado School of Mines and director of the Functional Biomechanics Laboratory (http://fbl.mines.edu/).