Training involves the communication of “ergonomic best practices” to workers and involves learning:
- How to properly use equipment to minimize stress on the body.
- How to change our behaviors to minimize stress on the body.
Proper use of equipmentThe introduction of any engineering control in the work environment should be accompanied by training in why was the change made and how the equipment should be used in order to take advantage of it.
Remember that involving workers in implementing engineering changes makes the training process much easier. Table 1 provides examples of some of the common training problems to share with workers when introducing engineering changes in the workplace.
Worker behaviorsChanging worker behaviors typically involves training the worker in proper body mechanics or providing training to develop a skill set that will reduce stress on the body in the performance of a job.
Training in proper body mechanics implies that we can define a “best” set of motions for the body when performing a task. This is an assumption that has been periodically challenged in the ergonomics literature.
- Lifting technique. Three general lifting techniques have been evaluated in the ergonomics literature: squat (knees bent, back close to erect), stoop (legs close to straight with back bent), and semi-squat (a lifting posture essentially mid-way between the squat and stoop techniques). There is little evidence to suggest one technique as being uniformly superior. The use of the squat posture, commonly recommended in training, is not well supported in the ergonomics literature as a means to reduce stresses on the low back. Researchers gravitate toward the semi-squat technique as a reasonable compromise posture for workers to adopt during low-level lifts, although training should assist lifters in discovering their individually appropriate posture and patterns of movement.
- General vs. specific training. Many ergonomists recommend providing workers with general lifting guidelines to allow them to discover their own appropriate posture/movement patterns. General guidelines include keeping the load close, avoiding twisting and avoiding high acceleration of the load (lift smoothly). In addition to general guidelines, object-specific lifting techniques should be defined and communicated. For example, how to position the body relative to the object in order to minimize reaches and twisting are important points to communicate via training. Lifting technique on low-back loading is task dependent (such as vertical start point of lift), and training in lifting technique cannot be based on only one technique advisable under all circumstances.3 It can certainly be argued that proper lifting methods should not be overly prescriptive. A prescribed lift method involving “abdominal hollowing” was not recommended over the users’ preferred lift style.4
Skills and reinforcementThere are a variety of job tasks where the skill (proficiency) of the worker will directly affect the ergonomic stresses on the body. For example, a number of computer users today have not received formal training to enhance typing skills. This absence of a skill set (typing skills) directly related to the job task (keying) may result in increased concentration on body parts (2-finger typist vs. touch typist), and increased forces when keying.
A concern is workers returning to old work habits at some point following ergonomics training. This speaks to the need for ongoing training and reinforcement of training principles. Reviewing training principles on an annual basis, or during the introduction of new work practices, has been proposed. Constant reminders such as posters, etc. also serve as reinforcements. The presence of an active ergonomics team keeps ergonomic principles on the “front burner.”
SummaryErgonomics training for workers should ultimately be viewed as how to do things a defined “right” way. To accomplish this, remember the following:
- An ergonomic assessment of the job is required to define what is the “right” way to perform the job.
- The behavior being taught must be under the control of the worker (do not expect safe lifting techniques in a poorly designed work environment).
- The behavior must be routinely reinforced, both through immediate feedback from supervisors, co-workers, ergonomic team members, as well as through periodic refresher training.
- You, H. et al. 2005. An ergonomic evaluation of manual Cleco plier designs: Effect of rubber grip, spring recoil and work surface angle. Applied Ergonomics. Vol. 36(5), pp. 575-583.
- Faber, G. et al (2007). The effects of ergonomic interventions on low back moments are attenuated by changes in lifting behavior. Ergonomics. Vol. 50(9), pp. 1377-1391.
- Kingma, I, et al. Foot Positioning Instruction, Initial Vertical Load Position and Lifting Technique: Effects on Low Back Loading. Ergonomics. 2004. Vol. 47(13), pp. 1365-1385.
- Butler, H., Hubley-Kozey, C., and Kozey, J. 2007. Changes in trunk muscle activation and lumbar pelvic position associated with abdominal hollowing and reach during a simulated manual material handling task. Ergonomics. Vol. 50(3), pp. 410-425.