SUMMARY & ANALYSIS OF THE OSU SRI STUDY: IMPROVEMENT OF PUSH/PULL FORCE ESTIMATES WHILE TURNING
One of our primary focuses here at Caster Connection is to make sure that our clients are protected from push/pull injury. Any improvements we can make in our testing is a critical component to help keep our clients safe. This study is one way we are doing that.
After our contribution to the study with the OSU SRI on push/pull forces with a single-axis force gauge, we were interested in turning forces. For this reason, we collaborated with the OSU SRI in the CDMI to understand push/pull force measurements while turning.
BASIC COMPONENTS OF THE STUDY
The SRI used 10 volunteers in this study. During the testing, they used two different force gauges, a three-dimensional hand transducer (the gold standard of push/pull measurement) and a single-axis-force gauge (the most common measurement tool in industry).
Before the tests were conducted, the subjects set a “natural” baseline by pushing with the hand transducer, which allows subjects to put two hands on the push/pull bar while moving through the push/pull motion. After this, the examiners used three main single-axis measurement strategies: pushing, pulling, and timed pushing (using a metronome over a 5-second interval) to compare these ratings to the hand transducer readings.
After the initial testing, the examiners we’re able to adjust the ratings mathematically to get them to match the “natural” readings, and in addition to this, they used mechanical attachments on the single-axis force gauge to get them closer to the “natural” push/pull force readings. These tactics allowed them to more accurately match the “natural” push/pull force using a single-axis force gauge that the subjects achieved using a hand transducer. They were then able to measure the push/pull force more accurately to what an associate using a single-axis force gauge might experience in the field.
3 MAIN TAKEAWAYS FROM THIS STUDY FOR COMPANIES MEASURING PUSH/PULL FORCE
There are three main takeaways from this study.
First, when we use a single-axis push/pull gauge in our facilities, we are normally underestimating the force that an associate exerts when they turn a cart.
Second, we need to make sure that we are keeping consistent time sequences when we measure push/pull on the turn. This will make sure that the results are consistent from measurement to measurement. The SRI study showed that 5 seconds, measured with a metronome, is a time sequence that reflects the “natural” push/pull speed of an associate in the field.
Finally, it’s critical that we use an adapter with the single-axis push/pull gauge. The SRI used the Shimpo padded ERGO-KIT in their study, which you can find here. This allows for a more secure surface on which to measure the push/pull force.
Using these three pieces of information will allow you to maintain a safer working environment, to understand turning push/pull risk, and to measure push/pull improvements more accurately.