Manual handling of loads is the practice carried out by workers during putting, lifting, holding, moving, pushing, or pulling a load. Mechanical handling of loads affects the health of workers and can cause musculoskeletal system disorders such as lower back pain because the extra strain is experienced by back muscles and bones and the natural resonant frequency of the lower spine is disturbed.
Manual handling is practiced mostly in environments such as factories, building sites, farms, hospitals, and sometimes even in offices. Heavyweight lifting practices have adverse effects on the whole body, but the most affected region is the lumbar region (lower back) because it is the part exposed the most to pulling, torsion, muscular stretch, and postural instability.
Risk Factors Involved in Lifting Heavy Load
- The risk of spine injury and pain increases if the load is heavy. A weight of 20-25lbs is considered heavy for most people.
- Muscle fatigue occurs if the weight is too large because posture instability occurs greatly when carrying a large weight.
- If the load is slippery, it can cause mechanical injury.
- Twisting and bending of the trunk cause extra stretching and pull of muscles, thus the risk of backache increases.
- Bent or awkward posture, e. bent trunk, raised arms or overstretched neck can cause cervical spine injuries, loss of normal curvature of the spine, neck pain, and stiffness.
There are some risk factors that are associated with the load. For example:
- Weight and size of the load. Heaving and larger weights are more likely to cause injury and pain along the spine.
- The distance of the load from the body. Holding the load further away from the body may increase the risk of back pain and injury.
- The height of the load in comparison to the height of lifter.
- The frequency and number of heavy loads that have to be carried throughout a specific time period.
The risk factors associated with work environment are:
- Working in a congested space that does not allow for flexible handling of the load.
- Intense vibrations.
- Excessive heat or cold, which may make it more difficult to carry or handle heavy objects.
- Slippery and dirty floor.
- Excessive noise in surroundings.
- Poor lighting.
- Strong air movements in surroundings.
Individual and lifestyle factors which have hazards for potential workers are:
- Age of the person.
- Medical history.
- Physical ability to bear the load.
- Weight of the person. People on the heavier side tend to be more prone to developing back issues. Maintaining a healthy weight is thus crucial in avoiding lower back problems.
- Previous physical trauma.
- Lack of training on how to handle heavy objects.
According to a survey carried out by EU-27 in 2015, 33% of the workers that were surveyed and who carry a heavy load have complaints related to health issues. The group that has the highest exposure rates is that of highly-skilled manual workers.
The Role of Your Spine in Lifting Weight
Our spine is composed of vertebrae and discs that are situated in-between each vertebral bone. It has 3 natural curvatures, 2 of which are concave, and 1 that is convex. The strength and resilience of our back are due to these curvatures and the shock-absorbing effect of intervertebral discs.
Due to this spinal shape, a person can lift very heavy weights that are greater than their own body weight. But it is observed that in workers who have to regularly lift heavy weights as part of their job, the resilience of the spine is gradually lost because frequent postural changes occur during their routine work and normal curvatures of the spine are lost during this practice.
Additionally, intervertebral discs may be injured, and nerves can become pressed. This causes pain and numbness not only in the back but also in the other body parts supplied by these nerves. So, it is mandatory for such workers to adopt precautionary measures in order to maintain good general and spinal health.
Safe Lifting Tips
Heavy lifters should adopt the following tips and habits to maintain their best state of health during their work routine.
- Always keep the weight closer to your body.
- Engage your abdominal muscles, and don’t place all the weight on your back, but rather shift it to the hips and legs to avoid low back pain.
- Always keep the spine straight so that its normal curvatures are not lost. Bend your knees instead of the back.
- Grasp the load strongly.
- Exercise to keep yourself and your spine in shape to ensure you have sufficient strength to carry heavy loads.
- Perform stretches regularly to offload some of the built-up tension on your spine.
- Use a lumbar belt (back support belt) which has a good effect on your overall body health as well as back health. It is the best preventive measure for a backache.
The back support belt allows for a redistribution of spinal forces during lifting which has a very beneficial effect. The belt also grips up your lumbar region which helps you maintain normal posture while you lift the load. It also increases lumbosacral support, thus decreases the erector spinae myoelectric activity. This also reduces strain, extra stress, and fatigue during a lift.
In other words, a support belt is beneficial not only in terms of alleviating existing back pain (including chronic back pain and persistent back pain), but can also provide back pain prevention.