**10. Why exposure assessment is important**

*Occupational Wellbeing*

diately if they do not like it.

'deadman' use (**Figure 3**).

In both of these sites, the workers took the trial and error method, i.e., they would continue with the devices if they like it and they would stop the trial imme-

Efficacy studies, usually, are those that proves the accuracy of an instrument or assistive devices to the degree it says it will. By that definition, both 'deadman' and 'hanger's helper' were ready to be assessed for their efficaciousness in the real field. Effectiveness studies, in construction are those that will prove whether any instrument/assistive device would be effective in making a permanent place in the

**9. The success behind the implementation: some precipitating factors**

There were precipitating factors behind the success of implementing the 'deadman' and electrical lift as an intervention. The participants of the intervention or the 'users' had suggested the 'deadman' after perceiving its beneficial use in reducing their overhead arm postures to hold drywall panels to the ceiling. Nevertheless, a brief yet imperative role was played by the safety management crew who gave substantial amount of importance on the safety features of the drywall job at this site. The management was dissatisfied with the potential hazards of the 'bucketing' or 'laddering activities and perceived the electrical lift and 'deadman' to be more stable and therefore safer. The spontaneously yielded to provide one of the two electrical lifts (that were present at the site for some electrical work) for ceiling installation and thus, offered a pivotal support to the

construction trade. This study did not evaluate the effectiveness.

**8**

**Figure 3.**

*Use of 'Deadman: narrow piece of panel'.*

The ceiling installation task have many physical exposures that are discussed under sections 3 and 4. These physical exposures are present throughout each cycle in case of a cyclical task or throughout all day (in case it is a non-cyclical task). For example, a ceiling drywall installer will go through the same physical exposures (such as heavy handling, overhead arm postures, back and neck stress) for each ceiling panel installation. Assessment of these exposures will give the opportunity to fix parts of the task. These parts would get fixated by modifying different activities. By doing thus, only a small part of the tasks can get rectified, however, the result oftentimes is a huge reduction in the physical exposure level. If exposure to MSD risk factor is reduced by modifying a task or activity, then usually the modified task or activity gets adopted by all the workers in the organization [14–16]. The next section will describe how and why the exposure was reduced.

### **11. The reduction in exposure**

The physical exposures and risk factors of drywall installation task were handling and holding more than 50 lbs in air with overhead arm postures while being on a ladder and continuously handling and handling such load. The idea of deadman did reduce some part of the exposure such as holding it with overstretched arm posture while raising it towards the ceiling. However, it is noteworthy that the worker standing on the floor still needed to hold the narrow 'deadman' piece with his hand. Deadman is 14 pounds in weight, that is much lighter than the panel weight. As a continuation to this intervention technique, the author was able to implement 'hanger's helper' (**Figure 4**) which was much stable in its base and could be placed on its own to hold the ceiling. These studies were conducted in real field and through the analysis of ergonomic observations at the pre and post intervention phases in real construction workplace settings, evaluated the efficacy of an assistive device for ceiling installation. Detailed analysis of the panel load effect on low back and shoulder joints of the installers were possible due to direct observation of the ceiling installation task at the real construction sites, through video analysis of the task and a clear picture of the shoulder and low back workload of the installers could be drawn. Prior biomechanical studies conducted in simulated laboratory environment did not

**Figure 4.** *Use of 'hanger's helper'.*

evaluate other biomechanical variables such as shoulder moments while holding the drywall panels to the ceiling, placing the panels to the ceiling, using the neck and head while holding the ceiling or while using the screwgun to attach those panels.

To assess the workers' perception about any reduction in the exposure of ceiling installation, they were anonymously asked questions about their perception on it. Moreover, workers' suggestions on further modification of the tool gave an insight to its future evolution. Hence these exposure assessment methods are an important addition in the long run research on future possibilities on marketing stronger and more stable version of the prototype.

### **12. The perception of the workers on the interventions**

The ceiling installers from the beginning of the study, accepted the idea of participatory research. To them it was something that can simultaneously change their work while they are also doing research. Also, they believed that as a workers' community they could identify what was an important concern, when it became an important concern and what was needed to address the concern. Throughout the installers were of opinion that they loved the interventions, they stated that release of panel loads from their shoulders and neck was the main reason that they liked it. Also, they felt much energetic at work.
