Smithing Biomechanics

[Mark Emig]

I agree with Doc. I use several different hammers depending on the job. I usually tell my students to hold the hammer just tight enough that it won't fly out of your hand, and never grip it tightly when it impacts the material. Luckily for me, I have had no issues with injuries-but I can't say for sure it's just the hammer technique. 

[Jack Evers]

I'm a farrier more than a blacksmith - read that as 1" by 3/8" is heavy stock - My main hammers are in the two pound range, one at about 1-1/2 pounds. On a few occasions when I had wrist soreness (from driving 60 to 80 penny ring shank nails in post and rail fences) , I was using 4 pounders, mostly just picking them up and dropping them, not swinging them. An arm therapist told me that anvil height was a biggy and to not get lazy and just pull my anvil out onto the tailgate, but to put it on my stand. I believe it was good advice. By the way, I am 75 years old and have to be more careful than I used to be.

[Eddie Mullins]

Very good reading here. I am 40, new to smithing, but come with a pre-existing injury to my right elbow (dominant hand). I hope to be able to forge for many years to come so the use of the best technique is certainly important in my case. I am using hammers 3 lbs and under, and trying my best to use a relaxed grip. I started out with a 3 lb cross pein I found to be too heavy, and purchased a 2 lb crossed pein I like quite well. I later modified the 3lb hammer ( http://www.iforgeiron.com/topic/32975-customized-8-hammer-project/#entry335783 ) and its a little lighter and more balanced now. I am begining to find I prefer using it when needing to move more metal as it requires fewer strikes to achieve the same results.

[Eddie Mullins]

duplicate post - sorry

[doc]

I'm a farrier more than a blacksmith - read that as 1" by 3/8" is heavy stock - My main hammers are in the two pound range, one at about 1-1/2 pounds. On a few occasions when I had wrist soreness (from driving 60 to 80 penny ring shank nails in post and rail fences) , I was using 4 pounders, mostly just picking them up and dropping them, not swinging them. An arm therapist told me that anvil height was a biggy and to not get lazy and just pull my anvil out onto the tailgate, but to put it on my stand. I believe it was good advice. By the way, I am 75 years old and have to be more careful than I used to be.

Very good point Jack. I think that having too high an anvil, especially if you use the death grip method puts increased load on your wrist.

[tzonoqua]

I am sure that is great advice, too, and I hope like you Jack, I am still swinging a hammer at 75 !!! :)

[anvil]

Howdy, thought I'd add my 2bits. My experience is much like Frank's. Started shoeing in '66. I used a 2-1/2# roundinghammer. Went to Turley forge '79 or 80. Been a full time smith ever since.y primary hammers are my 3# crosspien,9# singlejack, and a 1-1/2# crosspien from an old Willys axle. I have a 25# little giant. I like long hammer handles and choke them up. I like the counterbalance it gives me. I do not let the handle rest against my forearm.

I got into the "joy of movement" idea when shoeing horses. Basically this means keep your whole body loose and make it all be part of each swing. Turley introduced the idea of Tai Chi. It's a bit more formal, but the same basic concepts. Each hammer blow is "from your toes to your nose". Probably that came from Frank, not sure any more.

I had a 2 year slow time due to personal situation. When I tackled my next job, I noticed my grip was weaker. I actually nearly lost my hammer a few times. My tong hand hurt as did my tong upper arm. I had been a rollover. I was told that I needed to fuse the last four neck bones. I didn't. This was the problem I thought. After about two months, all was back to normal.

I have to be careful of high overhead stuff due to my neck, but normal range of motion for hammer swing is no problem. I believe staying in shape is critical for me.

Hope this helps.

[HWooldridge]

A couple of the above recent posts prompted me to add that I no longer grip tongs in my off hand to hold material.  I always either grasp material to be heated with tongs that have a ring permanently attached to one rein or I place a separate ring over the reins - the only exception is if I am able to handle the stock without using tongs.  This one small change really helped me focus on forging without worrying whether my grip would slip and made a big difference at the end of the day with regard to how tired I felt.  I think the late Bruce Lee's comments regarding "economy of motion" in the martial arts can also apply to any manual exercise - always aim to do the least amount of work in the shortest possible time while still achieving the desired result.

[Frank Turley]

Farriers would have a different take on tong holding, because they are constantly changing the gripping position on the hot horseshoe. Using a tong rein clip or link would not work, therefore.

 

Even a cold shoer who holds the manufactured shoe in his hand while hammer-shaping, is going to shock the holding hand occasionally.

[HWooldridge]

Farriers would have a different take on tong holding, because they are constantly changing the gripping position on the hot horseshoe. Using a tong rein clip or link would not work, therefore.
 
Even a cold shoer who holds the manufactured shoe in his hand while hammer-shaping, is going to shock the holding hand occasionally.

Agreed - I am not a shoer so tend to forge repetitive items such as scroll ends and such.

[Everything Mac]

I am curious as to what kind of hammer weights our female smiths are swinging? I don't imagine there is much if any difference but it would be interesting to see if they are getting the same results with a lighter hammer?

My female friends who've had a bash always prefer a lighter hammer to the one I've been using. I wonder if lighter hammers are being used, if joint problems are as common?


Andy

[billyO]

Hello again all, and thanks for the comments.  I think I'm ready to put some of my thoughts down for everyone to read.  Here goes:

 

Smithing Mechanics - Hammer head weight v. speed – myth v. fact.

What is it that we do?  We move metal, and in order to move metal we need to break the forces that are holding the metal molecules in a certain positon.  So what we are concerned about from a metal moving perspective is force, not work as I've read before.  Therefore, from a theoretical/physics/mathematical standpoint, it's the mass of the hammer head that is important, not the speed(velocity) of the hammer head, because although it's likely that everyone can swing a 3# hammer faster than a 5# hammer, you may be able to swing a 5# hammer faster than I can swing a 3# hammer. So from a mathematical standpoint, when one simith is trying to convince another that a 2# hammer is better than a 5# hammer, and another smith chimes in with the opposite, this is an apples to powerhammers argument.

However, we don't live in a purely theoretical world, but rather in a world where we -- living creatures with more soft tissue than hard -- try to shape and form materials that are almost always much harder and stronger than our strongest hard tissue. From this PT’s perspective, then, the argument is not whether to use a heavy hammer a little slower or a lighter hammer faster because from the standpoint of moving metal, the more metal you want to move, the heavier the hammer you will want to have.  Period.

(I like to use what I call “Limit Theory Thinking” in cases like this, so here’s what I mean: with enough control, you could draw a taper on ¼” stock with a 500lb powerhammer, (how many have seen videos of closing a matchbook with a power hammer?) but I challenge ANYONE to draw a taper on a 3” square with a 2# hammer. )
 
So, the issue is not how heavy a hammer you should use, because that will vary not only from person to person, but throughout each of our lives as our bodies change.  Normally, the progression for any individual would be this: lighter hammers when starting, progressing to heavier hammers as we develop our forging muscles, plateauing at whatever a manageable weight is until we age to a point where the body starts its natural deterioration process and we need to return to progressively lighter and lighter hammers (if we’re lucky to still be forging at that point).

So the argument shouldn't be about WHAT tool to use, since there's no one right answer to that, but rather HOW to use the correct tool safely.

 

When I get specific biomechanical reccomendations fleshed out a bit more, I'll start down that road. 

 

PS- regarding the personal anecdotes, there's a good pattern amongst all the success stories that would be worth paying attention to.  Let me know if you'd like my specific input on anything.
 

[doc]

BillyO

 

  I thought you were going to give us a perspective on our physical biomechanics not get into that same old saw about size of hammer equals force/work being done thing? Seems we can't ever get past who uses what to accomplish their work instead of talking about whatever you use within reason and how it affects our bodies.

 

  I for one would be really interested in knowing what your take is on how our bodies are impacted by the abuse they are given by the physical aspects of our work ! But not so much on your take of the physics of moving metal. It's just been talked about too much on this board and has become a kind of "chase your tail" type of discussion with no real consensus.

 

respectfully

Doc

[Matthew Parkinson]

useing the right grip on the hammer has a lot more to do with keeping you body safe than just about any thing else. I teach a lot and some of the biggest mistakes I see my students making are inproper hammer grip. the two most common are the tumb on the back of the handle and the death grip on the handle. the tumb over the handle will wreack your wrists and elbows I found this out early on to a painfull truth. the death grip will tire you out and lead to carpletunnel pain in the hands and wrists. I teach a loose handshake grip, this added to a good swing that uses all of you mar inplace of jsut the elbow or wrist will go a long way to protecting you body.

A few other thing I see in teaching that I notice can hurt you. 1 Bad stance at the anvil. that is standing to far away or at akward angles to the work and foreing your left arm to compinsate this will lead to elbow and wrist problems. 2 the death grip on the tongs/badly fit or made tongs. I find that if tongs are fit well to the work and have light springy reins every thing is fine, if on the other hand the reins are to heave forceing you to squeeze to hard or it they are ill fit again forceing yo to bear down in an attempt to hold the work this will lead to pain in the hands and wrists.

as far as long of short handle I like a short for most things but use a long for welding, as far a hammer weight I like my 4lb cross (Bertha) but I use the hammer that is best suited to the work at hand. heavyer stock =heaver hammer.

MP

MP

[billyO]

I thought you were going to give us a perspective on our physical biomechanics not get into that same old saw about size of hammer equals force/work being done thing?  
respectfully
Doc

That's next, like I said, when I'm sure I'm giving 100% accurate info. The reason why I put my thoughts on the physics of hammering is exaclty to avoid any questions in the future about specific equipment when I get into the biomechnics/postural recommendations. I also brought up the physics to point out the need to separate the apples from powerhammers from the repetitive discussions on the topic.

[Frank Turley]

I don't envy BillyO. Over the years, I have spent time pondering this subject. I think we need to take a holistic approach. One aspect is not more important than another. For example, hammer grip is not more important than being grounded nor loosening your joints nor the profile and movement of the swing. It's one ball of wax. And there is a crossover of disciplines. Ergonomics is fairly inclusive. It has to do with how we posture ourselves to any artifact, and how to avoid injury or illness in doing so. Sports is a big deal with money involvement, so Sports Medicine gets the nod socially. We never hear of ha ha Work Medicine, but wouldn't the two be very much related? or the same?

 

The subject is difficult to write about, because it excludes the visuals that one would see in a moving picture. I can spot someone who is struggling with their hammer and tongs, and I can go to them and offer suggestions, but it would tax me to write about what I saw and noticed. One thing I might mention. If the hammer is too heavy, during the initial lifting phase, the wrist "breaks downward" (droops markedly). Time for a lighter hammer.

 

I suspect that social-psychological attitude and approach may be involved in our subject at hand. I can think of two thought provoking books. The Reinvention of Work: A New Vision of Livelihood for our Time by Matthew Fox and  Shop Class as Soulcraft: an Inquiry into the Value of Work by Matthew B. Crawford.

[Rashelle]

I am curious as to what kind of hammer weights our female smiths are swinging? I don't imagine there is much if any difference but it would be interesting to see if they are getting the same results with a lighter hammer?

My female friends who've had a bash always prefer a lighter hammer to the one I've been using. I wonder if lighter hammers are being used, if joint problems are as common?


Andy

I use mainly a 2lbs followed by a 3lbs crosspein. Which will change to whatever size rounding hammer I make at Brian's in about a week. About the only time I use a smaller then 2 lbs one (even when forge welding I habitually use the 2 lbs) is when using a ball pein when riveting.

[thingmaker3]

Actually, there was a big study commissioned by a couple of the big name general contractors a while back. They were trying to reduce insurance costs by reducing sprain and strain injuries. They hired some heavy duty medical geniuses to look into the affair. The finding? Construction workers were suffering the identical strain and sprain injuries once common among athletes. The solution? Stretching out before working. They even coined the term "industrial athlete." Ha! Athletes with beer guts!

Sports is a big deal with money involvement, so Sports Medicine gets the nod socially. We never hear of ha ha Work Medicine, but wouldn't the two be very much related? or the same?

[John McPherson]

"Ha! Athletes with beer guts!"   Hey, I resent resemble that statement!!! Retract that sneer or I will toss a caber in your direction, buddy. :o 

 

The older I get, the better I used to be. But stretching and breaks in routine do help, a lot. People do best with lots of walking and varied tasks everyday, too much sitting or standing on hard surfaces wears on a body.

 

Technology sometimes comes to the rescue in unexpected ways. The advent of the auto-darkening welding hood has decreased neck problems in weldors. Something about that old nod/twitch to drop the hood 500 times a day causes pinched nerves.

[thingmaker3]

I will NOT retract that beer! I need it to maintain my athletic profile! What? Sneer not beer? Oh. Never mind.

 

I took some yoga classes a couple decades back. I found I had an increased awareness of my own muscles and skeleton as a result. When folk say "listen to your body" they really mean we should have body awareness - feel how our muscles move and whether they are straining. BillyO says tai chi works just as good as yoga for this.

[billyO]

BillyO says tai chi works just as good as yoga for this.

 Or did I mean yoga is just as good as tai chi?.?.?. :unsure:

 

What I do mean is that there is no "gold standard" for specific exercises, only the exercise principles.

[hildenmw]

Look into kettlebell work outs.
Marc

[billyO]

I don't envy BillyO.

Nobody should... :rolleyes:

 

Over the years, I have spent time pondering this subject. I think we need to take a holistic approach. One aspect is not more important than another. For example, hammer grip is not more important than being grounded nor loosening your joints nor the profile and movement of the swing. It's one ball of wax. And there is a crossover of disciplines. Ergonomics is fairly inclusive. It has to do with how we posture ourselves to any artifact, and how to avoid injury or illness in doing so. Sports is a big deal with money involvement, so Sports Medicine gets the nod socially. We never hear of ha ha Work Medicine, but wouldn't the two be very much related? or the same?

All true, but there is Work Medicine, only it's usually referred to as Occupational Medicine, as I'm sure you know.  I ran a PT clinic for 4 years that was attatched to a physician group that referred to themselves as an Industrial Medicine clinic.  And exactly the same thing.

 

The subject is difficult to write about, because it excludes the visuals that one would see in a moving picture. I can spot someone who is struggling with their hammer and tongs, and I can go to them and offer suggestions, but it would tax me to write about what I saw and noticed.

This is what I'm attempting. . .

 

One thing I might mention. If the hammer is too heavy, during the initial lifting phase, the wrist "breaks downward" (droops markedly). Time for a lighter hammer.

 

I suspect that social-psychological attitude and approach may be involved in our subject at hand. I can think of two thought provoking books. The Reinvention of Work: A New Vision of Livelihood for our Time by Matthew Fox and  Shop Class as Soulcraft: an Inquiry into the Value of Work by Matthew B. Crawford.

I'll look into those titles, thank you. And I think psychology has a significant part too.  An example is how I've approached this topic on this site:

I've been thinking about this since the first day I got involved in Blacksmithing when I heard that the "correct" hieght of an anvil is where your knuckles are when standing upright, etc.  2 thoughts ran through my head almost simultaneously, a result of my profession, I guess, which were, "Is that true for everyone, and if so, what are the joint mechanics we are trying to idealize with that statement?"  (An example I deal with in my profession on a regular basis may clarify: The "textbook" says that the correct height of hand grips of any assitive device such as cane, walker, crutches is the crease where the wrist meets the forearm when standing erect.  But I often have to modify that up or down one or two notches depending on the specific body structure of the individual patient.)

So instead of coming right out and questioning thousands of years of tradition, I thought I'd sneak up on it by asking for info on injuries.   :wacko:  Wow, I forgot how much I hate psychology.....   

[Everything Mac]

Look into kettlebell work outs.
Marc

Kettlebell swings are excellent for lower back strength.

[billyO]

Kettlebell swings are excellent for lower back strength.

When done correctly, possibly, but VERY damaging if done incorrectly.  IMO, to risky for most, there are safer alternatives.   

 

Now, for those of you who have been doing them for years, this isn't me telling you to stop, because obviously you've trained your muscles and have the proper balance between strength and flexibility to be able to control the dynamic motion and momentum caused by the kettlebells, so, by all means, "Use it or lose it!"   

 

I'd just advise those that want to start, BE CAREFUL and make sure someone who knows what they are looking for watches you do the exercises a few times to ensure that you're building. not destroying your body.