Ergonomics 4 Schools

The Learning Zone

Explore the Learning Zone

Manual Handling

Comfortable manual handling What is manual handling?

Manual handling activities include carrying and moving loads, as well as pushing, pulling, lifting up and putting down.

Manual handling doesn't just mean this...

...it also includes all these types of actions.

 

Manual handling activities
 

Manual handling injuries

More than 25% of the accidents reported to the UK Health & Safety Executive (HSE) each year are associated with manual handling, most resulting in lower back injuries. These are common among occupational groups in which repeated and prolonged strain is put on the spine e.g. farmers, nurses, machine operators, miners, maintenance staff and delivery personnel. Over 70 million working days are lost in the UK each year due to back injuries.

With about 70% recurrence rate for back injuries, it's much better to avoid getting an injury, than to try to fix the situation afterwards. Although some manual handling injuries are due to a single incident, many are cumulative and result from carrying out the same activities repeatedly, with poor posture. Nursery school teachers are an example of an occupational group who are exposed to cumulative risks. They can involve lifting from a low level as well as bending forward to talk to and feed young children.

It is not just the back that may be injured. Other muscle groups and joints such as shoulders, arms and legs, are involved in manual handling and may be damaged by bad lifting techniques. Feet can also be damaged by loads being dropped on them. You can decrease the risk of injuries by thinking about how you handle things, and using efficient and comfortable working postures during the handling activity.

 

The spine

Anatomy

The vertebral columnCurves of the spineThe structure of the back allows it to support our head, to provide anchor points for the rest of our skeleton, and provide flexibility when we move.

The vertebral column is formed of 33 bones, called vertebrae. It has four curves, two of which,  thoracic and pelvic, are concave and are formed before we are born. The other two, cervical and lumbar, are convex and are formed when we begin to sit up and walk.

The vertebrae are bound together by powerful ligaments, and stabilised by small muscles along the entire length of each side of the vertebral column. The joints between the bones of the lumbar, thoracic and cervical regions are slightly moveable and contain fibro-cartilaginous structures called discs. The discs act as buffers (shock absorbers) between the vertebrae to withstand forces of compression.

Although the amount of movement between any two vertebrae is limited, the sum of the movements which take place at all the joints make the spine, as a whole, a very mobile structure. The spine can bend forwards (flexion), backwards (extension) and sideways (lateral flexion), and can twist (rotation).

Good posture

The posture that you adopt when performing a manual handling activity is determined mostly by what you need to see to do the task, and how you handle the load. For example, if you are pushing a tall load then you might bend sideways to see around the side. A good posture is efficient in terms of the amount of muscular effort required, and does not result in discomfort or injury. Certain sorts of handling place your back at risk of injury because the combination of poor posture and heavy load place too much strain on it.

The muscles and joints in your back receive least strain when you are upright and are maintaining your natural curves in your spine. Therefore, you will be putting least strain on your back if you do manual handing activities with your back in this position. Remember too, that generally your muscles are strongest in their middle third range of movement. This means that your arms muscles, for example, will be better able to cope with a lift when your elbows are bent.

 

 
Legal requirements for manual handling

The Manual Handling Operations Regulations 1992 came into force on 1 January 1993 to implement the European Directive 90/269/EEC. They supplement the general duties on employers by the Health and Safety at Work etc. Act 1974 and the Management of Health and Safety at Work Regulations 1992. These regulations require employers to make a suitable and sufficient risk assessment of the risks to the health and safety of their employees while at work. The manual handling regulations put a duty on employers to assess possible risks associated with manual handling, and to reduce any risks that they find.

 

 

Investigating handling activities

Where do we carry out manual handling activities?

At work, handling will be related to the industry in which we are employed. For example, a nurse will be involved in moving patients, and a postal worker with letters and parcels. You may be able to think of manual handling activities, such as carrying chairs, which take place in your school.
At home, manual handling activities include carrying shopping bags, mowing the grass, and moving furniture.
Weightlifting is an example of a sport that involves manual handling.

What types of loads do we handle?

There are basically two types of loads: animate people and animals, and inanimate all other loads. Loads come in different shapes and sizes. Animate loads tend to be more complicated as they can be uncooperative and unpredictable! Inanimate loads include boxes, bags, furniture and machinery.

How do we carry out manual handling activities?

Often you make contact (interact) with loads by gripping with your hands. You can also use other parts of your body to carry out manual handling activities, for example, you can push furniture by leaning on it with your hips. Some loads have handles which can make them easier to get hold of to pull, push, carry or lift. Other loads can be moved using handling equipment such as cranes, hoists, trolleys and wheelchairs.

For many years people were taught to lift by keeping their back straight. However, back injuries have not decreased and so this method of lifting has been questioned by researchers. It has been found that in practice, most people use a semi-squat posture, with both the back and knees slightly bent. So people make their own mind up and will lift in the way that they think is easiest (freestyle technique) in terms of energy efficiency and time. It is important that you know how to reduce the risks associated with moving the load.
 

 

Assessing and reducing the risk of injury

In workplaces, employers are required to assess the risk to their employees, from manual handling.  Risk assessments are carried out by trained assessors who decide whether or not there is a risk of injury and how much of a risk it is. This includes looking at:
The task - How often is the task performed and how long for? Does it have to be performed quickly?
The individual's capacity Who is doing the task? Are they physically capable of carrying out the task safely?
The load How heavy is it? What shape is it? Does it have handles? Is it hot or cold, or wet - do gloves need to be worn?
The environment Where is this task being carried out? Indoors or outdoors? Is it cold and/or wet? Does the space restrict good posture? Is the ground clear and flat?

If an assessor thinks that there is a risk of injury, the employer must take certain steps to reduce the risk. The first step is to see if they can avoid the task that involves the risk. An example of this is for a doctor to visit a patient at home rather than the patient being brought into the hospital by the ambulance staff. This would eliminate the task of the ambulance staff having to push the patient in a wheelchair from their house to the ambulance, and then into the hospital.

If the task can't be avoided, then the next option is to minimise the risk of injury. Risk can be reduced in lots of ways:

  • Make sure that there is a good grip on the load - that hands, the load and any handles are not slippery.

  • Make sure that the area around the task is clear of obstacles. Make sure that doors are open and that there is nothing on the floor that could trip someone or make them slip.

  • Use mechanical equipment, for example, push a shopping trolley to the car rather than carry the bags.

  • Reduce the amount that is handled or split it into smaller pieces.

  • Extend the time taken to do the job by taking breaks to ensure that the muscles have time to recover.

  • Get someone to help.

Look out for and take note of any information that might affect your handling operation. This information might be found on the load itself or in the surrounding area.

Manual handling sign

Manual handling sign

Manual handling sign

 


Good lifting technique

You can help yourself by making sure that you are using your muscles efficiently. Here's some more tips for safer lifting:

  • Lifting actions are strongest when performed close to the body.

  • The strength of a lifting action is strongest at around knuckle height to waist height and falls off rapidly above and below this level.

  • Pulling and pushing actions are strongest, and therefore require less effort, when the load is being moved in a straight line.

  • Symmetrical lifting - using two hands - is safer than using one hand.

  • Plan the lift before you begin and make sure that you know where you are going, and that your path is clear.

  • If you are picking something up off the floor or from a low shelf, try to bend your knees and keep your back straight. Let your leg muscles do the work.

  • If you are lifting with someone else, make sure that you both of you know what you are doing before you begin.

 

 

Manual Handling FAQs

Q. I have to carry my rucksack around all day and some days it is very heavy. Is this going to do long term damage to my spine? Answer
* Also see a research report on schoolbag weight and musculoskeletal symptoms in New Zealand secondary schools

Q. What are the ergonomics of a lawnmower, or pushing or lifting a lawnmower?  Answer

Q. I'm currently designing a racking system that is going to store rowing boats. The system is going to be rotary and adjustable to allow boats to be lifted at the optimum height. Can I use ergonomics to work out this height? Answer

Q. I am designing a backpack. How could I involve the use of biomechanics? Answer

Q. I am looking into manual handling in a nursing home. How does ergonomics apply to this? Specifically I am looking at hoisting people into a bath with a mobile hoist.  Answer

           
Reference
Pheasant, S (1998) Bodyspace. Anthropometry, Ergonomics and the Design of Work. (2nd Ed.) London: Taylor & Francis ISBN 0748403264

Acknowledgments
Content: Sue Hignett
Images: IMSI's MasterClips Collection