Do anthropometrics and functional measurements predict performance in the Sandbag Lift Task?

Abstract

Background: The Sandbag Lift Task (SLT) is a component of the Canadian Armed Forces (CAF) pre-employment fitness evaluation, which mimic demands of common military tasks. Understanding the relationship between anthropometrics, dynamic balance, core stability, and isometric strength may provide insight into SLT performance. Purpose: The purpose was to examine if anthropometrics such as BMI and limb lengths and circumferences, FMS trunk stability, anterior reach of YBT-LQ, isometric knee and hip extension strength, and core stability predict SLT performance. An exploratory purpose was to examine hip, knee, and ankle kinematics throughout SLT performance. Methods: Twenty-four participants (12 males; 12 females) completed two sessions 48-96 hours apart. Session one included height and weight measurements and SLT performance (mins/sec), which was recorded for kinematic analysis. Session two assessed predictors of limb lengths and circumferences (cm), trunk stability pushup (0-3), anterior reach asymmetry (cm), isometric knee and hip extension strength (N), and single leg wall sit hold (secs). Linear regression determined SLT variance explained by these predictors. Hip, knee, and ankle kinematics throughout SLT performance were derived from markerless motion capture. Results: For the total sample, single leg wall sit hold, leg length, and trunk stability pushup explained 55.1% (adjusted R2) of SLT variance. In males, single leg wall sit hold, shank circumference, and trunk stability pushup explained 48.1% (adjusted R2) of SLT variance. In females, thigh circumference, trunk stability pushup, shank circumference, isometric knee extension, shank length, and single leg wall sit hold explained 88.5% of SLT variance. Conclusion: These findings suggest development of targeted interventions to potentially optimize training for SLT performance with an additional focus on sex-specific interventions.