Keeping Neutral Hand and Wrist Postures
Posted on July 12, 2022 | in Ergonomics
VelocityEHS’ Ryan Cowart explains why it’s essential to maintain neutral postures when it comes to working with the hands and wrists.
Hi. I’m Ryan Cowart with Humantech (now VelocityEHS Ergonomics), consultant and ergonomics engineer. One of the things I’ve noticed is that organizations are really good at when performing ergonomics assessments on-site is identifying excessive forces to the elbows, shoulders, and the lower back. But sometimes overlook applied forces to the hands and wrists. That’s why this diagram is here – to identify how strong we are in awkward postures.
So, we can see in a neutral posture, we can create 100% of our voluntary contraction straight through the forearm. Whenever our hands go up to extension, when our fingertips are pointed towards the ceiling, we can create 75% of strength, so that’s a 25% decrease in what we could already have in neutral postures. Now, when our hands and wrists go towards flexion, when our fingers towards the ground, we can only create 45%. So, we’re eliminating a significant amount here between neutral postures and flexion. So, it definitely pays to have neutral postures whenever performing a task, be it horizontally oriented or vertically oriented. We see these types of issues in cart handles, the proper tool or equipment for the job, or even whole-body clearance when performing maintenance tasks.
I’m Ryan Cowart. Thanks for tuning in.