**8.1 What did the workers suggested from the focus groups**

In two different sites, the workers approached the outcome of the focus group quite differently:


*Occupational Wellbeing*

**6**

**Table 1.**

**Static frame description**

**7. Research design**

and stepping on the ladder

ceiling, drywall in air

Carrying the drywall panel in overhead arm posture

moments generated in the ceiling installers.

v) attaching the panes to the ceiling.

Holding the drywall panel (overhead arms) to the

*The selected static frames from the videos for 3DSSPP analysis.*

**Baseline PHASE Intervention PHASE**

Lifting the drywall in overhead arm posture Sliding the drywall panel to the electrical lift, both

This intervention study was designed as a quasi-experimental study with no control group. The only experimental group consisted of the five drywall installers.

workers whether for a 60 lb., 80 lb. or 100 lb. drywall panel. The same study found that low back loading while lifting a 100 lb. drywall panel exceeds 760 lb., the maximum value recommended by NIOSH in the Work Practices Guide for Manual Lifting. All four lifting techniques also involved risk of perturbation in postural balance [5]. Yuan et. Al., [2] found that the average disc compression force during installation of drywall panels exceeded value of 760 lb. (3400 N) disc compression force, set by NIOSH as the recommended action limit. The highest value of disc compression force in this study was found to be 1721 lb. (7748.8 N) and was sustained for an

average of 8.5% of the total 8 hour work shift, or around 41 minutes.

vals to make direct observations and coded postures into a PDA.

**5. PATH (posture, activities, tools, and handling) data collection**

**6. 3DSSPP (three dimensional static strength prediction program)**

3DSSPP (3 Dimensional Static Strength Prediction Program) was utilized in order to find out the compressive forces generated at low back and shoulder

The sequence of static postures was selected while performing the task of ceiling drywall installation. The selected static postures from the task videos were not made at a defined interval of seconds or minutes. Instead, the postures were selected corresponding to the main set of activities. For example, the task of installing the drywall to the ceiling at the intervention phase comprised the following six activities, i) loading the panels to the electrical lift, ii) lifting the panels while being on the lift, iii) raising the panels to the ceiling, iv) holding the panels to the ceiling,

PATH method [6, 7], was used to code posture, activities, tools used and materials handled at every moment for at least 3–4 hours every day with a hierarchical taxonomy. Since the drywall installation task is cyclical in nature, we collected data for a week that is absolutely representative of the whole task. We used fixed inter-

One feet in air, maintaining the previous posture The arms are down, maintaining the previous

arms down

posture

by the electrical lift

and supported by 'deadman'

Keeping the hands on the drywall panel being raise

Overhead arms, drywall being lifted to the ceiling

#### *Occupational Wellbeing*

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 immediately if they do not like it.

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 construction trade. This study did not evaluate the effectiveness.
