Home OSH Answers Ergonomics Manual Materials Handling (MMH) Introduction

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Manual materials handling (MMH) means moving or handling things by lifting, lowering, pushing, pulling, carrying, holding, or restraining. MMH is also the most common cause of occupational fatigue, low back pain and lower back injuries.

MMH is always hazardous but the level of hazard depends on what you are handling, what the task is, and what the conditions are at the workplace or work site.

For example, the material or load that you are handling may be:

• too heavy for the task that you are doing,
• located too high or low for a safe lift,
• too big or may have a shape that makes it hard to handle,
• wet, slippery, or have sharp edges that makes it hard to grasp, or
• unstable or can shift its centre of gravity because contains some that can flow (e.g., a partially filled drum or concrete in a wheelbarrow), or
• too big to let you see where you are putting your feet.

The task can make MMH hazardous if a worker:

• uses poor lifting techniques (lifting too fast, too often or too long; lifting with back bent or while twisting or reaching too far; lifting while sitting or kneeling, etc.),
• has to move material over long distances,
• not taking appropriate rest breaks; insufficient recovery time, and
• has a combination of handling tasks (e.g. lifting, carrying and lowering).

The conditions where you are working can also contribute to hazards of MMH and result in injuries; for example,

• walking surfaces that are uneven, sloping, wet, icy, slippery, unsteady, etc.,
• differences in floor levels or walking surfaces,
• poor housekeeping that causes slip, trip and fall hazards,
• inadequate lighting,
• cold or very hot and humid working conditions,
• strong wind or gusty conditions,
• working at high pace,
• movement is restricted because of clothing or personal protective equipment, or
• space is small or posture is constrained or both.

OSH Answers has (or will have) information on various topics related to manual materials handling such as:

• MMH and health hazards/injuries,
• Back injury prevention,
• Back belts,
• Pushing & Pulling - General,
• Pushing & Pulling - Handcarts,
• Shovelling,
• Recommended weight limits (RWLs) and the Revised NIOSH Lifting Equation,
• Handholds on load and gripping aids (I and II),
• General safe lifting and MMH practices,
• safe MMH practices for specific kinds of loads (compact loads, small bags, large sacks, drums, barrels, cylinders, sheet materials (e.g., metal, glass),
• Layouts for working and storing materials,
• Materials flow, and
• Mechanical aids for handling and transporting materials (I, II, Levers).