Predicting Performance On A Repeated Lift-and-Carry Task: 1776 Board #3 June 2, 1: 00 PM - 3: 00 PM.

Repeated lifting and carrying (LAC) of heavy objects is a common job requirement for Soldiers. It is often safer and more practical to assess a Soldier’s LAC capacity by administering physical fitness tests (PFTs) rather than performing the actual task. PURPOSE: To determine the effectiveness of PFTs to predict Soldiers’ performance on a repeated LAC task. METHODS: 437 male and 187 female Soldiers performed a sandbag carry (SBC) task while wearing a fighting load without a weapon (approx. 71lbs). Soldiers lifted and carried 16 pre-filled sandbags (40lbs each) a distance of 10m to build a simulated fighting position (4 long x 2 wide x 2 high) as fast as possible for time (minutes). Soldiers also performed the following 14 PFTs while wearing shorts, t-shirts, and athletic shoes: dumbbell squat lift (SL), handgrip, upright pull, Illinois agility test (IA), arm ergometer (AE), 9kg powerball throw, isometric biceps curl, 2kg medicine ball put (MBP), 20m sled drag, standing long jump (SLJ), 300m sprint, beep test (BT), push-ups, and sit-ups (SU). Stepwise multiple linear regression was used to predict SBC performance. RESULTS: The average SBC completion time was 2.1 + 0.9 minutes. The model obtained using all possible predictors was: SBC(min)= 4.286 -0.009(SL kg) - 0.005(SLJ cm) - 0.004(AE rev/sec) + 4.351(IA sec) + 0.011(SU #) - 0.001(MBP cm), R2=0.64 (p<0.001), SEE=0.53 minutes. The percentage of the variability in the prediction equation explained by each of the variables was: SL=49%, SLJ=9%, AE=4%, IA=1%, SU=1%, and MBP=1%. Measuring 6 tests to predict one task may not be practical, but use of the first 3 tests (SL, SLJ, and AE) achieved an R2 of 0.62. CONCLUSIONS: Three simple PFTs can be used to predict individual LAC capacity. These data demonstrate that when assessing only one task it may be advantageous to actually administer the task in question. However, the same PFTs could potentially be used to assess performance on multiple job tasks, thus saving time and resources. Variables such as time, required equipment, participant safety, and available testing personnel must be considered when designing occupational testing procedures.