Effects of Rucksack Military Accessory on Gait Dynamic Stability
Seong H Moon1, Christopher W Frames1, Rahul Soangra2,3
1School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ,85281, USA.
International Journal of Prognostics and Health Management
|June 6, 2022
Summary
Soldiers experience reduced lower extremity dynamic stability when wearing rucksacks. This study found carrying equipment like the All-Purpose Lightweight Individual Carrying Equipment (ALICE) and Modular Lightweight Load Carrying Equipment (MOLLE) significantly impairs gait balance compared to normal walking.
Area of Science:
- Biomechanics
- Military Medicine
- Human Factors Engineering
Background:
- Rucksack load carriage is a significant factor in U.S. Army soldier injuries.
- Load carriage may negatively impact lower extremity stability and gait balance.
- Understanding these effects is crucial for injury prevention and performance optimization.
Purpose of the Study:
- To assess the impact of different rucksack types on gait and lower extremity dynamic stability.
- To compare the stability during simulated marches with and without load carriage.
- To quantify changes in dynamic stability using the Maximum Lyapunov Exponent (LyE).
Main Methods:
- Five subjects performed simulated rucksack marches on a treadmill using the Motek GRAIL system.
- Gait data was collected using the Dynaport Inertial Measurement Unit (IMU) system.
- Trials included normal walking, walking with the ALICE rucksack, and walking with the MOLLE rucksack, each carrying 20kg for 200 seconds.
Main Results:
- Normal walking exhibited significantly lower LyE (indicating greater stability) compared to walking with ALICE (P=0.000007) and MOLLE (P=0.00003).
- No significant difference in LyE was found between ALICE and MOLLE rucksack conditions (P=0.441).
- Subjects demonstrated significantly improved dynamic stability when not wearing a rucksack.
Conclusions:
- Wearing a rucksack significantly reduces lower extremity dynamic stability in soldiers.
- Both ALICE and MOLLE rucksack use lead to comparable reductions in dynamic stability.
- Findings highlight the importance of load carriage management for maintaining soldier stability and preventing injuries.
