Patterning of Musculoskeletal Injuries in the U.S. Army: A sociocentric social network analysis

Musculoskeletal injuries (MSKI) are a highly prevalent and costly threat to U.S. Soldier health and medical readiness, affecting over half of all Soldiers. Most research and mitigation efforts have focused on identifying sociodemographic and physical factors contributing to MSKI. Yet mounting evidence underscores the importance of social relationships on health.
This research sought to empirically measure social relationships and MSKI patterns within military social networks by applying cross-sectional sociocentric social network analysis to two distinct combat-arms Army battalions (N=795; Cohort 1[C1] N=413, Cohort 2[C2] N=382). We measured self-reported social interaction networks by asking Soldiers to identify up to 10 Soldiers from their unit with whom they socialized outside of duty hours. The networks were analyzed descriptively, including mean number of social ties nominated. A multivariate logistic regression with quadratic assignment procedure (MR-QAP) was used to examine dyadic similarity in injury status controlling for network dependence, sociodemographic variables, and known risk factors for MSKI (e.g., age, gender, body mass index).
The majority of participants were young (mean age C1:26.6 ± 5.62 years; C2:26.96 ± 6.16 years), overweight (mean BMI C1:27.12 ± 3.88, C2:27.43 ± 19.45), male (C1:86.4% and C2:90.3%), White (C1:72.0%, C2:66.2 %), single (C1:48.8%, C2:51.3%), had a mean time in service of 5 (C1:67.66 ± 53.08 months) or 6 years (C2 :56.88 ± 56.88 months), and more than one-fourth reported being on a duty-limiting profile for a MSKI (C1: 26.0%, C2: 27.7%). Injured Soldiers were significantly more likely to socialize with other injured Soldiers outside of duty hours compared to uninjured Soldiers (C1: OR= 1.255, p=.040, C2: OR=1.336, p=.008). High modularity scores (C1: .767; C2: .788) indicated that Soldiers with and without MSKI formed distinct, cohesive subgroups. Additionally, Soldiers with MSKI had 0.76-1.5 fewer social ties on average (C1: p=.025; C2: p=.003) compared to uninjured Soldiers.
Injured soldiers were distributed non-randomly within military units, forming distinct subgroups and reporting significantly fewer social ties compared to uninjured soldiers. Future studies should explore whether social disconnection increases susceptibility to MSKI through social selection or influence, whether MSKIs reduce social connection and integration, or if both dynamics interact.
1. Describe how social network analysis reveals patterns among U.S. Army Soldiers with MSKI, including subgroup formation and differences in social ties between injured and uninjured Soldiers.
2. Analyze the role of social relationships in MSKI distribution within military units, focusing on non-random clustering of injured Soldiers and implications for injury risk and unit cohesion.
3. Evaluate sociocentric social network analysis as a tool for future studies and interventions to mitigate MSKI in military populations, addressing social, demographic, and physical factors.

DISCLAIMER: The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government