Evaluating Load Carriage System Static Fit in Canadian Armed Forces Soldiers

Abstract

Load carriage systems (LCSs) are critical to soldier performance and safety; however, their effectiveness is often compromised by poor fit and discomfort during use. Poorly fitting equipment has been associated with reduced mobility, increased discomfort, and elevated risk of musculoskeletal injury, highlighting the need for improved evaluation approaches. While objective methods exist to quantify body–equipment interaction, subjective evaluations remain essential for understanding user experience in applied military settings. This thesis aimed to (1) identify which aspects of perceived fit and comfort most strongly influence overall equipment acceptability, and (2) compare these perceptions across LCS configurations, specifically between the current in-service Clothe the Soldier (CTS) system and the newer Body Armour Carriage System (BACS). Subjective responses were collected from Canadian Armed Forces soldiers across 10 equipped configurations using structured surveys that assessed regional fit, comfort, and overall acceptability. Linear mixed-effects models were used to evaluate differences between configurations and examine predictive relationships between variables. Results demonstrated significant differences across configurations, with BACS systems consistently receiving higher ratings of fit and comfort compared to CTS (p < 0.05). Perceived fit and comfort were strongly associated, and both significantly predicted overall acceptability (p < 0.001), with comfort emerging as the primary determinant. In contrast, total system weight was not a significant predictor of fit or comfort (p > 0.05) and demonstrated a small negative association with overall acceptability. These findings establish a subjective baseline of perceived fit under standardized conditions and highlight the role of comfort in equipment acceptability. Optimizing comfort and body–equipment interaction appears more critical to acceptability than reducing system weight alone. This work provides a foundation for future research integrating subjective and objective approaches to support the development of more effective and acceptable LCSs.