We all suffer occasional pain and discomfort, but work shouldn’t hurt.
There is strong and consistent evidence that physical factors in the workplace and how work is organized can greatly increase a person’s chance of developing an MSD. Work can also aggravate an existing MSD injury and hinder the return to work process.
Despite this evidence, it is common to ignore the strong contribution of the workplace and instead, blame workers’ low back or shoulder pain on individual factors such as “gardening”, “susceptibility” or “genetics”. This argument does not take away from the independent contribution of work to the development and worsening of MSD symptoms
This independent and substantial contribution of work to the development of MSD can be eliminated or reduced by making changes to the workplace.
People differ in how they respond to MSD hazards, and how intense the hazard is before they have problems. This is the same for other occupational hazards like noise or dust. We are all different. Some people are taller, some are heavier, some are stronger, and some are older.
A tall worker may have to bend over to work at a regular-height table. You can’t change the height of the worker, but the organization could fix this hazard with an adjustable-height work surface.
Fit the work to the worker! Do not make the worker fit the work. This is the central idea of ergonomics.
Examples of force include the force exerted on a box during lifting or the grip force to hold a hand tool. If the force exerted is high, the muscle around the joints must contract forcefully and are likely to fatigue. The high forces, over time, can injure nerves or other tissues.
Posture is the position of the body and its joints – an elbow is bent (flexed) or straight (extended). Some positions of a joint are stronger and healthier than others. These are sometimes called neutral postures. An awkward posture is one where the joint is weaker or more likely to fatigue or become injured. These awkward postures, over time, can lead to fatigue and increased risk of developing an MSD.
Repetition describes how the postures and forces vary over time. Does the person spend a long time bent over (a static posture), or are they frequently bending over then standing up (repetitive work)? Closely related concepts include recovery (does the body have sufficient recovery time) and duty cycle (the proportion of time that the body is working). These factors are strongly influenced by Work Organization and the workplace.
A worker may be exposed to vibration in two main ways:
A tool that digs into a worker’s hand or the pressure on the kneecap when kneeling both create local contact stresses. These contact stresses can, over time, injure the skin or cause blisters or injure the muscle, ligament or bone underneath the skin.
There is some evidence that working in cold temperatures is associated with an increased risk of developing MSD. Different mechanisms have been proposed. However, working in the cold often requires a worker to wear a glove and gloves can greatly increase the effort required to grip objects.
The word “psychosocial” is often used when talking about causes of MSD. It can be confusing. It is useful to separate “workplace psychosocial” factors from “individual psychosocial” factors.
Workplace psychosocial factors refer to the perceptions of the work environment that have an emotional meaning for workers and managers. Examples include overload or lack of control.
Individual psychosocial factors refer to individual characteristics, such as psychological distress.
The work organization determines to a large extent the type and degree of psychosocial work factors experienced by workers. Different work organizations will create different psychosocial workplace factors. Electronic performance monitoring is an example of a work organizational factor that leads to negative psychosocial work factors. Workplace psychosocial factors are important for workers’ health in general, mental health, as well as MSD.
With this in mind, multiple studies show a consistent pattern of workplace psychosocial factors that are also MSD hazards. Psychosocial factors include a mix of jobs, work environments and organizational characteristics. They include factors such as low job control, low decision latitude, conflicting job demands, or low supervisor support. On the positive side, these hazards are generated by the organization and therefore can be changed by the organization.