A Study On Hand Ergonomics In Relation To Knife Handles

Status
Not open for further replies.
S

Steel_Magnet77

Joined
Apr 10, 2025
Messages
16
I am trying to figure out the optimal handle shape that supports very effective ergonomics. More specifically ergonomic ideas and implementation strategies for a bushcraft knife handle. One of these goals was to create a handle that was overall sized to give the user their greatest grip strength based on their relative TCLm measurement. One article explained that TCL-2cm will give the length for when they have the greatest grip strength. I also found for teenagers the formula y=x/7.2+3.1cm which I do not exactly trust...

The problem with the TCL-2 measurement is that it only gives you one length dimension; however on a handle face area there are two dimensions (W and L). The width will affect the optimal grip span that was found, so I am unsure how to create a handle that produces a specific grip span. I want to find the width and length dimensions of a handle that will give the user their greatest grip strength based on their relative TCLm measurement. That is my biggest question at the moment. I will welcome any and all ergonomic ideas that can be applied to a knife handle.

1-s2.0-S0169814104000186-gr2.gif
 
Wow, this is...politely, SUPER overthinking it. A woods/camping knife should have a fairly generic shape to it, able to be held in virtually any grip without issue, with a palm swell and no protrusions to create hotspots or finger indents/choils. Also, given that there have been companies making these sorts of handles for decades, I don't know that using spacial geometrics is going to yield something appreciably better.
 
Right - human hands can easily adapt to different shapes of knife handles and this is why Sebenza and XM-18, for example, even though having quite different handles can feel both good in the hand. The only things that I'd watch out is the handle not to be too short, too narrow/thin, and with sharp corners/edges.
 
Steel_Magnet77 said:
I will welcome any and all ergonomic ideas that can be applied to a knife handle
Click to expand...

Did you first 3D scan a sufficient sample set of human hands across a broad spectrum of ages for endomorphic, mesomorphic and ectomorphic body structures, in order to aggregate the data and form a comprehensive and adaptable model? If not, you are doomed to fail.
 
IMO you need to build a device. Mold a plastic handle with some palm swell and build a few strain gauges into it. Surround with strong clay and have your users grip the device and squeeze, make up a few of them. Create optimization curves for each gauge, determine a multi variate routine to create a generalized solution for their force output. Create one last device. Have them squeeze until they within 1 standard deviation of their generalized solution. Remove their hand, cast the clay handle into a negative, form a handle to the positive for each individual user.

Boom, custom handle optimized for grip strength. Now you're a billionaire.
 
NapalmCheese said:
IMO you need to build a device. Mold a plastic handle with some palm swell and build a few strain gauges into it. Surround with strong clay and have your users grip the device and squeeze, make up a few of them. Create optimization curves for each gauge, determine a multi variate routine to create a generalized solution for their force output. Create one last device. Have them squeeze until they within 1 standard deviation of their generalized solution. Remove their hand, cast the clay handle into a negative, form a handle to the positive for each individual user.

Boom, custom handle optimized for grip strength. Now you're a billionaire.
Click to expand...
The problem here is that my immediate question is: who's squeezing a knife that hard when using it? That's a quick way to get muscle fatigued in your forearms, and it doesn't assist the tool in doing the work any better. Sure, a steady, good grip on a knife is good. Squeezing it like it owes you money is wasted energy. This is goes back to what I was telling the OP about neutral handle shapes. A neutral handle shape most effectively fills up the hand, and allows it to close around the tool naturally, reducing hand fatigue, while also allowing the most possible use-cases.

I had a friend who had a similar idea, on how he was going to design the best handle shape ever. He got a block of modeling clay, gave it a good squeeze, decent hammer grip orientation. Then he took a block of wood and using a Dremel, carved it to mimic the shape of that squeezed clay block. His first admission was "This handle sucks." 🤣
 
To be serious for a sec, S Steel_Magnet77 , grip strength and ergonomics are distinct but related concepts when it comes to a knife handle. Are you doing this for a school project, or are you making a knife?
 
I like to have a oval shape with a bit of flat sides for good indexing, a center swell and a front and rear knob to prevent linear slip forward or backwards. Rounded corners with a 5(8 to 3/4 inch thickness side to side and 1.12 height at center swell max. I really don’t care for the crescent or curled shape just straight.
 
Richard338 said:
Loveless said a good handle should be comfortable. Not sure what was going on when he came up with the subhilt.
Click to expand...
Unless you can come up with a citation for that, you need to modify the verbiage. Your post is not family friendly.
 
Status
Not open for further replies.
Back
Top