Lift and Carry
The lift and carry of heavy components yields complex exposures producing levels of biomechanical stress that vary as a function of the load handled, postures used, and the 
frequency, duration, and periodicity of the physical activity employed. Other work-related factors may also lead to musculoskeletal trauma, such as pushing and pulling activities and non-neutral postures.
Data Requirements
Provide the system description, including the weights and dimensions of all items weighing over 31 pounds (lbs) that will be lifted. Provide a detailed use scenario (e.g., handling environment, required tasks and physical demands, frequency of lifts).
Health Protection Criteria
MIL-STD-1472H contains design guidance for efficient handling. Maximum design weight limits based on lifting team size are provided.1 Reduction multipliers for lifting risk factors (e.g., lifting frequency, lifting height, load asymmetry) are considered in the determination of the safest load that a team is permitted to handle. Each item required to be manually lifted/carried should be labeled with their weight and lifting requirements.
Head-Supported Mass
A quantitatively descriptive property which represents the loading
on the neck from wearing head protection systems that may affect Soldier
performance and health. This term may also be used to refer to the helmet and
helmet-mounted system components.
Data Requirements
Provide the weight of the HSM component, center of mass offset, detailed use scenario (e.g., duration, frequency of use, vibration exposure), and operational baseline helmet configuration (e.g., MOS, aviation, ground).
Health Protection Criteria
Currently-approved health protection criteria are not available for health hazards associated with exposure to HSM for mounted or dismounted ground Soldiers. The U.S. Army Aeromedical Research Laboratory (USAARL) 
developed performance and acute injury risk guidelines for Army aviation which describe acceptable ranges for mass properties of Army aviation-specific HSM.2,3 Medical and safety personnel, specifically those at the USAARL, are currently working to develop applicable health protection criteria. Completed studies establish preliminary performance guidelines; however, injury criteria are still being researched.
As a result of the preliminary performance guidelines, it is recommended that the rear and forward offsets relative to the tragion notch be limited to -2 and 9.5 centimeters, respectively, and the preliminary maximum allowable helmet mass be limited to 2.5 kilograms.4
Load Carriage
The total loading on the body from carrying
clothing and equipment. The load is typically carried over long distances or
durations, and may be worn, affixed, or 
sometimes hand-carried. Load carriage has
been associated with musculoskeletal trauma, and movements or exertions while carrying
increased loads may elevate the risk of injury. Examples of systems
requiring load carriage include body armor, backpacks,
personal weapons, radio handsets, and other equipment attached to the body.
Data Requirements
Detailed system and use scenario information are required to assess the risk of injury associated with load carriage (e.g., component size and weight, distribution of weight, diagram/picture, method of attachment to the body, backpack type or design (if applicable), other equipment worn and carried by the Soldiers using the system, distance and duration expected to carry load, required tasks while carrying load, environmental conditions).
Health Protection Criteria
MIL-STD-1472H provides design criteria for load carriage1. Individual portions of portable equipment shall not exceed 35 pounds, unless the individuals carrying the load do not need to maintain the pace of infantry movement. The total load carried (i.e., all equipment, clothing, and weapons) shall not exceed 30% of the user's body weight for close combat operations, or 45% of the user's body weight for marching. Additional MIL-STD-1472H design criteria provide suggestions for reducing the risk of musculoskeletal injuries (e.g., distribute and balance the load throughout muscle groups, design the center of gravity as close to the spine and waistline as possible, design the load to permit freedom of movement).
For more information and guidelines for assessing musculoskeletal trauma, see Technical Guide 351C, Health Hazard Assessor's Guide.
References
(1) DOD. 2020. MIL-STD-1472H. Department of Defense Design Criteria Standard: Human Engineering.
(2) USAARL. 1998. Mass Requirements for Helicopter Aircrew Helmets (Report No. 98-14). Prepared by B.J. McEntire and D.F. Shanahan. Fort Rucker, Alabama.
(3) AFRL. 1994. Vertical Impact Testing of Two Helmet-Mounted Night Vision Systems (AFRL Technical Report #AL/CF-SR-1994-0013). Prepared by C. Perry. Wright-Patterson Air Force Base, Ohio.
(4) USAARL. 2019. Preliminary Head-Supported Mass (HSM) Performance Guidance for Dismounted Soldier Environments (USAARL Technical Memorandum No. 2019-11). Prepared by A. Madison. Fort Rucker, Alabama. (Note: Limited Release)
