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Elevated jackhammer support: Development and evaluation of a jackhammer support device to reduce musculoskeletal injuries among construction workers
RS2002/03-DG09
Final Report Date: June 2005
| Principal Investigator: |
Gordon Thiessen (British Columbia Institute of Technology) |
For more information about this development grant project, please contact Gordon Thiessen.
Issue
Using jackhammers in construction work often involves supporting the device in an elevated position or other ergonomically unsound posture. Between 1996 and 2000, jackhammer related workers compensation claims in BC totaled almost 1 million dollars and resulted in over 5,822 days lost from work.
Due to the lack of electric jackhammer support devices, construction workers sometimes create a makeshift support device for the jackhammer. However, most of these attempts fail, due to lack of portability, long set-up/tear-down time or reduced maneuverability. This project aimed to design an effective jackhammer support device, which could increase both safety and productivity in the workplace.
Key findings
- A jackhammer support device has been designed and a prototype built.
- Field test results suggest the device may reduce musculoskeletal strain and improve safety and productivity in jackhammering work.
Objectives
- To design, build and test a jackhammer support device.
- To field test the device with construction workers who use jackhammers on a daily basis.
Method
Based on input from construction workers, several physical and performance requirements (design inputs) were identified for the jackhammer support device. The device would need to:- eliminate or significantly reduce the biomechanical loading placed upon the construction worker when supporting a jackhammer,
- be portable within the construction site as well from site to site,
- function with commercially available electric jackhammers,
- have easy to understand instructions for use,
- be useable in a variety of situations and conditions,
- withstand typical construction site conditions, including water, dirt, and dust; and hits by concrete slabs as they are removed by the jackhammer.
Based on these criteria, an initial prototype (alpha prototype) was developed. The alpha prototype was based on a SCARA robot arm (Selective Compliance Assembly Robot Arm), with modifications at the pivot points to create greater flexibility.
A universal bracket was designed to allow different jackhammers to be used with the system. Varying methods of supporting the jackhammer were also developed, for locations with:
- a ceiling no higher than 10 feet,
- a ceiling higher than 10 feet, or without a ceiling,
- standard construction scaffolding onto which the main hinge could be anchored at any height.
The jackhammer support device was then tested and found to exceed design requirements.
The next step was field testing with four construction workers who perform jackhammering operations in the normal course of their daily duties.
A questionnaire was administered to participants, who were asked for feedback on perceived exertion, likeliness of use, ease of use, perceived safety, rest to work ratio, rate of work and rate of exertion.
A biomechanical analysis was also conducted. This included a Rapid Upper Limb Assessment (RULA) and use of a two-dimensional biomechanical model to estimate tissue stresses at the lumbar, spine, shoulder and elbow.
Conclusions
The researcher concluded that the device may reduce musculoskeletal strain and may be effective in reducing strain related injuries in construction work. The researcher also concluded that use of the device may improve safety and increase productivity in jackhammer work.
Future directions
An assessment is underway to explore the feasibility of bringing the jackhammer support device to market.
Publications and presentations
This research project was featured in the June 2005 issue of WorkSafe Magazine: “Jackhammer support arm takes the load off”, by Anne-Rachelle McHugh, p. 10-11.
Hammer Drill Support Arm video, Windows Media Player, 3 minutes and 48 seconds: