Lower back pain is one of the most prevalent causes of limitation of activity and absenteeism in the workplace. According to a World Health Organization report, which included lower back pain as a priority disease, an estimated 149 million work days are lost annually in the USA as a result of this condition. Around 80% of the population experience lower back pain at some time during their life and the incidence is highest in the 35 to 55 year age group — in other words, in the active work force.
Additionally, workplace injuries are a major contributor to lower back pain, being second only to hand injuries as the most prevalent type of injury at work. Back injuries also represent 20% to 25% of all compensation claims and most of these injuries are caused by preventable workplace stressors.
Mechanisms of Lower Back Pain
The spinal column is composed of vertebrae, which surround the network of spinal nerves, which carry messages to all parts of the body. Vertebrae are separated by fluid filled discs that act as shock absorbers; ligaments keep the spinal column in place and enable movement; and muscles on both sides of the vertebrae help with lifting, pulling, and pushing.
Lower back pain is most often the result of damage to ligaments or muscles in the lower back. As with any other musculoskeletal injury, overextension of the ligaments and/or muscles can lead to stretching or tearing and result in varying degrees of pain, inflammation, and limitation of movement. Pain can vary from mild discomfort to severe and debilitating pain.
Treatment of Lower Back Pain
Depending on the severity of the injury and the resulting inflammation or muscle spasm, healing can occur within a few days or take up to a month or longer. A mild sprain may be successfully treated with ice and analgesics and/or non-steroidal anti-inflammatory medications. Continuing with normal work and activities can actually contribute to relieving the condition. In more severe cases, the employee should visit a health care provider for assessment. For severe pain, opioids may be prescribed, which could have safety implications (Learn more in Prescription Opioids and Safety Sensitive Work) if the employee returns to high risk work.
Non-drug therapies for lower back pain include physiotherapy and chiropractic treatment and should definitely be considered when back pain persists for longer than four weeks of self-treatment and pain medication. Physiotherapy includes manual treatments and acupuncture, as well as recommending back strengthening exercises. It has been shown to work well in treating lower back pain and preventing recurrence, especially if the treatment is started early. Chiropractic treatment, or spinal manipulation, is another treatment option and is safe when performed by a licensed practitioner.
More serious causes of back pain include a herniated vertebral disc, broken vertebrae, spinal stenosis, degenerative disc disease, and osteoarthritis. Pressure on the spinal nerves is usually involved in these conditions and more extensive treatment is required, including possible surgery. This could involve long periods away from work or even permanent disability.
Causes of Back Injury at Work
While a back injury can be the result accidental trauma, such as motor vehicle accidents and falls, it is more often caused by overexertion of the ligaments and muscles of the back.
- Manual handling of materials, the most frequent cause of compensable injuries. This includes lifting, bending, stretching, carrying, pushing, pulling and twisting, often requiring the use of excessive force
- Sitting at a workstation for long periods of time — this includes working on computers, especially if the work environment is not properly adjusted to ensure correct posture through good ergonomic design and practices.
- Repetitive tasks, including tasks such as manual packing of goods, which are often accompanied by long hours of standing as well as twisting.
- Driving long distances, particularly driving over rough terrain
- Operating heavy moving equipment
Factors which affect the function of body, such as not being fit enough for the job, exhaustion, and extreme heat or cold can also predispose the employee to back injury.
Workplace Back Pain Prevention and Management
Working conditions, including the environment and how tasks are performed, can contribute significantly to causing lower back pain or aggravating an existing condition. Although it is unlikely that back injuries at work can be completely eliminated, a comprehensive approach to assessment of working conditions, ergonomic design of the working environment and tasks, as well as employee education, can make an impact on prevention.
Risk assessments should include the biomechanical, physiological, and psychological demands of jobs. Where possible, jobs should be made physically easier, for example using powered or mechanical materials handling aids, adjusting the heights at which materials are handled, reducing the weight of materials, or assigning two or more people or lift a load. Workers performing jobs which put them at high risk of back pain, such as continuous lifting, should be given more frequent and longer rest breaks in order to avoid fatigue and the resulting reduced physical ability. Pressure to complete tasks in a hurry not only causes mental tension, but also physical tension, which makes muscles more prone to injury.
Many back injuries occur when employees are required to perform physical tasks that are not within the normal scope of their work and for which they do not have the required level of physical fitness. Avoid allocating tasks which are beyond the normal abilities and limits of a particular employee. Employees new to jobs requiring physical exertion should also be given time to adjust by allowing them to do less strenuous work for part of the day or by offering additional rest breaks or stretch breaks.
All incidents of reported back pain or injury should be investigated for the cause and contributing factors so that recommendations can be made on how to redesign the job or working environment to prevent future occurrences.
Employee training programs should include awareness of ergonomic principles and safe working practices. This includes correct body posture and safe materials handling practices such as warming up before performing physically demanding tasks as well as using rest periods to relax muscles and to prevent fatigue from building up. Employees should be able to identify and control risk factors that could cause lower back pain. All lower back pain and any incidents causing lower back injury must be reported so that contributing factors can be identified and corrected.
The employer should provide support and follow-up when an employee has experienced an episode of lower back pain or a back injury. The employee might not be able to return to his or her normal duties right away and transitional work arrangements should be planned with the employee. This might entail a different job or modification of the job. Modification could include shorter working days, more rest breaks, or adjustments to the working system or work station. Adjustments to the physical working environment, especially if it impacted on the initial episode of the back pain, may also prevent recurrence of the condition. Up to 75% of those who experience lower back pain have another episode within one year.