Field evaluation of a modified intervention for overhead drilling.

Drilling holes into concrete or metal ceilings is one of the most physically demanding tasks performed in construction. The work is done overhead with rotary impact hammer drills that weigh up to 40 N. The task is associated with pain and musculoskeletal disorders at the wrist, forearm, shoulder, and back. The mechanism of injury is thought to be the high forces and non-neutral shoulder and wrist postures applied during drilling. Previously, we described a field study of a foot lever and inverted drill press intervention devices that received poor usability ratings compared with the usual method for overhead drilling based on problems with mobility and productivity. Using a participatory intervention model, feedback from construction workers (N = 13) was used to develop a new intervention design that incorporated a wheeled tripod base and a unique method of aligning the drilling column to vertical. A different group of construction workers (N = 23) evaluated usability and fatigue of the new device during their regular overhead drilling in comparison with the usual method. Four of 12 usability ratings were significantly better with the intervention device compared with the usual method. Subjective shoulder fatigue was less with the new intervention (1.1 vs. 3.3; scale 0 to 5; p < 0.001). This difference was supported by objective outcome measures; the mean hand forces during drilling were 26 N with the intervention compared with 245 N with the usual method. The percentage of time with the shoulder flexed or abducted to more than 60 degrees was less with the intervention compared with the usual method (21 vs. 40%; p = 0.007). There was significantly less head extension with the intervention compared with the usual method. There were no significant differences in overall productivity between the two methods. This study demonstrates that a new intervention device for overhead drilling has improved usability and subjective fatigue ratings compared with the usual method. These improvements are most likely due to the reduced hand forces, reduced shoulder abduction and flexion, and reduced drilling time.

A new method for overhead drilling.

In the construction sector, overhead drilling into concrete or metal ceilings is a strenuous task associated with shoulder, neck and back musculoskeletal disorders due to the large applied forces and awkward arm postures. Two intervention devices, an inverted drill press and a foot lever design, were developed then compared to the usual method by construction workers performing their normal overhead drilling activities (n = 14). While the intervention devices were rated as less fatiguing than the usual method, their ratings on usability measures were worse than the usual method. The study demonstrates that the intervention devices can reduce fatigue; however, additional modifications are necessary in order to improve usability and productivity. Devices designed to improve workplace safety may need to undergo several rounds of field testing and modification prior to implementation.

Overhead drilling: comparing three bases for aligning a drilling jig to vertical.

PROBLEM: Drilling overhead into concrete or metal ceilings is a strenuous task done by construction workers to hang ductwork, piping, and electrical equipment. The task is associated with upper body pain and musculoskeletal disorders. Previously, we described a field usability evaluation of a foot lever and inverted drill press intervention devices that were compared to the usual method for overhead drilling. Both interventions were rated as inferior to the usual method based on poor setup time and mobility. METHOD: Three new interventions, which differed on the design used for aligning the drilling column to vertical, were compared to the usual method for overhead drilling by commercial construction workers (n=16). RESULTS: The usual method was associated with the highest levels of regional body fatigue and the poorest usability ratings when compared to the three interventions. CONCLUSION: Overall, the 'Collar Base' intervention design received the best usability ratings. IMPACT ON INDUSTRY: Intervention designs developed for overhead drilling may reduce shoulder fatigue and prevent subsequent musculoskeletal disorders. These designs may also be useful for other overhead work such as lifting and supporting materials (e.g., piping, ducts) that are installed near the ceiling. Workplace health and safety interventions may require multiple rounds of field-testing prior to achieving acceptable usability ratings by the end users.

DEVELOPMENT AND EVALUATION OF A NEW DEVICE FOR OVERHEAD DRILLING.

Drilling overhead into concrete is a strenuous task that is associated with shoulder, arm, neck and back musculoskeletal disorders due to the forceful and awkward aspects of the work. This common task is done to hang pipes, ducts and trays and is performed by construction workers in the electrical, pipe fitting, sheet metal, ironwork and carpentry trades. In this project, alternative devices for overhead drilling were developed in order to reduce the high shoulder loads. The design premise for the alternative devices was adopted from interventions developed on construction sites. These devices were evaluated for usability, productivity, and fatigue in two rounds of testing by 30 construction workers performing their usual overhead drilling. After each round of testing the device designs were modified based on feedback. The final design was associated with much less arm fatigue but similar productivity compared to the usual method for overhead drilling. The feedback, design suggestions and field testing by experienced construction workers was vital to the successful development of these devices. Field testing were done with real tasks, in diverse field settings, with subjects familiar with the task. Multiple rounds of field testing and redesign can significantly improve the safety and usability of new tools. Having experienced workers accessing the new tools can help with determining if and how a new tool is compatible and beneficial to current work practices.