HANDLING TECHNIQUES WHEN PUSHING AND PULLING
Here are some practical safety tips to remember to prevent back or other injury when handling loads that are being pushed or pulled.
Set stance and pace. To make it easier to push or pull, employees should keep their feet away from the load as much as possible and go no faster than walking speed. This will prevent them from becoming tired too quickly.
Choose and maintain handling devices. Aids – such as wheelbarrows, push carts and trolleys – should have handle heights that are between the worker’s shoulder and waist. Devices should be well maintained with wheels that run smoothly. The law requires that equipment is maintained. When you buy new trolleys, etc., make sure they are of good quality with large-diameter wheels made of suitable material and with casters, bearings, etc., that will last with minimum maintenance. Consulting your employees and safety representatives will help, as they know what works and what doesn’t.
Calculate force. As a rough guide, the amount of force that needs to be applied to move a load over a flat, level surface using a well-maintained handling aid is at least 2% of the load weight. For example, if the load weight is 400 kg, then the force needed to move the load is 8 kg. The force needed will be larger, perhaps a lot larger, if conditions are not perfect (e.g., wheels not in the right position or a device that is poorly maintained, the ground or floor surface is not smooth). The operator should try to push rather than pull when moving a load, provided they can see over it and control steering and stopping.
Compensate for slopes. Employees should get help from another worker whenever necessary – especially if they will be negotiating a slope or ramp, as pushing and pulling forces on slopes greatly increase. For example, if a load of 400 kg is moved up a slope of 1 in 12 (about 5°), the required force is over 30 kg in ideal conditions – good wheels and a smooth slope. This is above the guideline weight for men and well above the guideline weight for women.
Adjust for uneven surfaces. Moving an object over soft or uneven surfaces requires higher forces. On an uneven surface, the force needed to start the load moving could increase to 10% of the load weight, although this might be offset to some extent by using larger wheels. Soft ground may be even worse.
Push instead of pull when possible. It’s easier to maintain proper body mechanics – protecting your back – when pushing, versus pulling a heavy item.