Chain saw injury to the left arm & hand

[Bobcat_pa]

I think it was Kevin that provided a www link that lead me to this info:  http://www.osha.gov/SLTC/etools/logging/manual/logger/chain_saw/body_parts/body_parts.html

I started to think of the possible sources or ways that one could inflict injuries to these different areas of the body.  The left hand and arm was the most injured area, and I just do not realize what people are doing, or not doing, to make this the #1 injury location.   Can you give some input?   Some "not to do's " ?   I have quite a few SC hours and never had an accident, but I really can not think of why this body area is #1.    Bob

[beenthere]

My understanding is that your left arm (hand) is forward and closest to the saw, when holding the saw and when in a sawing position while bucking, dropping a tree, reaching for limbs, and cutting brush. I suspect the left leg and left foot is right up there with the arm and hand.  My chaps (two pair now) have cuts in the left leg. Good friend had a saw come out of his left hand (kick back) and run under his palm (ugly!). Just a few of my thoughts and understanding. Good to protect that left side with protective equipment.
SC hours?  

[Bobcat_pa]

I assume that my operating method is like most folks:  left hand on the front handle bar, set the chain break with the left forearm, and release the break with my right hand.   I can easily see how the legs, especially the left, can be involved in an accident if you are not careful.   But, the left hand high rate is still a question.   Bob.

[Minnesota_boy]

I don't know if other people get injured from tis as I haven't been injured yet, but the procedure that scares me the most is reaching forward to release the chain brake while the saw is running.  While limbing balsam fir, the brake on my saw would frequently lock and it sure was a chore to shut down the engine to reset it, then find a place to put the saw down to restart it, then climb over the limbs to get back to where you had been limbing.  After about 5 times on the same tree, one tends to just reach out to the brake and reset it an go on limbing.

[IndyIan]

Maybe there are alot of injuries on the left arm from cutting and bucking branches and trees under tension?  I could see how someone might get whacked pretty good on their left arm.
Also if you don't hook your thumb your left hand can get into the chain when you get tired

Minnesota_boy,
I use my chain brake all the time when limbing, everytime I move my feet it tricky terrain, and always reset it with my left hand with my thumb still hooked around the handle.  The chain on your saw should stop when the saw is idling.  If it doesn't don't use it, get it fixed!  

Also look into how to start your saw using a standing technique, it makes life easier.
I couldn't find a link that shows the technique but basically you pinch the rear handle between your thighs, hold the saw with your left hand and pull on the starter cord with your right. I would recommend getting a logging safety manual or even better take a course, makes sawing much more fun when you know your doing it right!
Ian

[Minnesota_boy]

Ummm....Ok, I hold the rear handle between my thighs, hold the front handle in my left hand and pull the starter handle with my right hand.  Just where does that rear handle go if the saw kicks back instead of starting?  

[Bobcat_pa]

Appreciate your comments.   I must praise the GOL classes for programming my brain to 1: set the chain break with the left forearm (hands never need to leave the handles),  2:  starting the saw in a standing position,  3: always set the chain break if you are uncertain of your footing, or moving more than one step.     I am sure my chain brake will wear out early, but it is an inexpensive part when compared to an injury.

Even before I was taught how to start a saw standing, I always felt a little out of control when starting on the ground.   I guess the pros with those big heavy saw must start on the ground, but most of us are using smaller units and the standing position is very functional, & safe.   I will admitt that when first learning to start standing,  the male anatomy does send out some fear signals to the brain, but some practice overcomes this problem.       Bob.

[Gus]

Being a south paw I use the saw both ways depending on my position in reference to the tree. I think that most injuries to this area are caused by getting to comfortable with the situation, thus letting up on ones grip ever so lightly. A human cannot react fast enough to overcome a kick back in progress. The only recourse is to grip the handle hard and keep it gripped and be ready, always ready for that ultimate kick back.
Most kick back situations I've been in, I usually can't tell exactly why it kicked back until investigating. It happens sooo fast.
I consider myself lucky to have never been hurt by a kick back but have helped haul people to the hospital that were. It ain't pretty.

[jokers]

Minnesota_Boy, that`s why they call the saw between the legs "the nutcracker". The saw should be positioned so that you are pulling the rope sideways rather than up and it won`t crack any nuts.  

Left hand/arm/leg injuries are most prevalent because of their closer proximity to the business end of the saw when operated by the typical right hander. Not having the thumb of the left hand wrapped around the top handle also adds to the risk, especially in a kickback.

Russ

[slowzuki]

I generally find I work more beside the saw than behind when limbing and noticed the chainbrake wouldn't contact my wrist if kick back occured (I'm also out of the arc of kickback)

This still bothers me so I've been watching to see if there are other cutting situations where I'm on the side of the handle.  Brushing seems to be one of them.

Other than a really firm grip I can't see what else to do?

[Minnesota_boy]

The chainbrakes are inertia driven instead of relying on wrist contact.  Putting them in front of the wrist just gives a little more protection.

[beenthere]

MN boy
There is something else I didn't know. So a sharp rap or drop or jolt to the saw or bar will kick the brake on?  Learn something new every day that I didn't 'knew' before. Thanks

[Kevin]

To test the brake, hold the saw about a foot and a half off the top of a stump and let the bar nose drop onto the stump while you hold the rear handle.
The brake should engage.

[IndyIan]

Yep, the brakes do work on inertia, I've had mine go off on small kickbacks where it took me a second to figure out why the saw quite cutting...
Slowzuki,
I think the main thing is that when your in the kickback zone your wrist should engage the brake, if your not in the zone then it's not a problem.
One example is clearing the lower branches off a spruce or fir you want to fall.   I wade into the tree and hold the saw parallel to me at shoulder height and run it down the side of the tree, cutting off all the limbs on that side, continue doing this around the tree in a clockwise rotation and your ready to cut it down.  I hold the saw by the side of the wrap handle so my wrist won't engage the brake but also I'm not in the kickback zone so no problems.

Ian

[L. Wakefield]

   er, so, I don't see many answers taking up those times when the saw is running and only held in 1 hand- shouldn't happen- but it does- and that hand is almost always the *right* hand. I know I've done this (never said I was smart..)- I don't *think* I have ever tried to cut something I'm holding in my left hand with the running saw in my right hand. That just leaves the whole body too open, not to mention the saw doesn't work well that way. One hand doesn't have the leverage.
 
  But I have been known to kick something over into the right position and hold it with my foot while I was cutting.  lw

[IndyIan]

1 handed cutting!  
I guess I've never thought of it.  I find after a while my 18 lb saw is hard enough to handle with 2 hands.     I guess I'm not the guy on a step ladder playing arborist either...

I do admit to holding wood with my foot though...  I've got the big orange saw boots so a small mistake shouldn't result in stiches.   Although I'm sure someone's seen a demo where chainsaw boots get sawed in half in a second.

Play safe!
Ian

[Gus]

This conversation reminds me. When they first came out with chain breaks we used to take them off and throw them away. We thought they just got in the way of doing business. Couldn't figure out why any one would want a saw with a contraption like that hanging on it. One time I bought a new a a a a I think it was a 038 stihl, I decided to cut awhile with it before I took it off. Had a couple minor kick backs and figured that DanG thing wasn't so bad after all. :-/ Then realized the break really never got in the way, it was my thinking getting in the way( or the lack thereof). Sheesh  

[L. Wakefield]

   O ho, I HAVE to tell this story. It was back when I'd just bought my Husqvarna 51- my first saw- and *I* was close to 51 by the- maybe still in my *late* 40's. And so I didn't know from chain brakes, or not chain brakes. They told me about it, and I read the instructions, but it percolated in 1 brain cell and out another.

  So I go out to fix fence, me and my widdo saw. And I bumped around on something or other and knocked the brake on. So blade won't turn.

  Now like I said, I'd forgot all about this feature. So I took my widdo saw up to Mike and his buddy Billy- Billy is a grad of Maine Maritime academy and cleared his own land to build a house, Mike has been cutting wood since he was a teenager-
gone through 10 saws likely. And of course with their vastly greater experience I asked them what the H*** was wrong with my widdo saw. So they scratched their heads over it for an hour before determining that it must be *completely* disassembled to figure out what the H*** was wrong with it. (No, they didn't read the instructions- why should they, knowing all there was to know about saws- and I blush to admit that *I* didn't re-read them either at this point.

  So after it was all in pieces and they had to admit defeat, I took it back to where I bought it, and endured the ribbing and the lectures that attended putting it back together and releasing the chain brake. Under warranty but nonetheless they taxed me a bit for the reassembly.

 So it just goes to show you- hmmm.. what does it go to show you?

  I don't use it too often, and it caught me off guard again down in the barn this fall- I thought I might have rusted it somehow so the chain wouldn't turn- but the lightbulb flickered on dimly after a bit and I released the chain brake- sure enough, I had dropped the saw off a coupla hay bales onto the floor- and it was OK again.  lw

[smokechaser]

Ok I give up.

How do you suppose that the chain brake on a saw is intertia driven.  Are you trying to say that the impct of dropping the saw on the tip of the bar will engage the brake???  What inertia exertion force are we speaking of??  

Please explain what it is you mean.  
Confused

[Ianab]

My understanding of the Inertia Brake is that if the saw kicks back it will usuall spin around it's centre of mass. This happens very quickly and the Inertia of the stationary chainbrake handle is enough to engage the brake?
Dropping the saw onto the tip of the bar has a similar effect, the saw stops and the brake handle is still moving, so it's inertia engages the brake. This is used to test the operation of the brake.
I have read it is therefore important not to trim or lighten the brake handle, this may prevent it working properly. Any other thoughts on this?

Ian

[Bobcat_pa]

Regarding my original question, I never considered not wrapping my thumb around the front handle bar.   I can see how the left hand could be injured much quicker with a four-finger grip.  That thumb really increases physical control in that split second kickback/up situation.    Thanks for bring this out.    Bob

[Kevin]

Any other thoughts on this?Ian

The inertia braking system may work but how well can only be determined with the chain in motion.
If the brake band doesn't grip the clutch drum tightly the chain won't brake properly.

[Ianab]

This is true Kevin, it's a 2 part test.
One - Make sure the brake is working correctly when it is applied manually with the chain moving
Two - Make sure the inertia action engages the brake

As you point out it is actually 2 seperate items, and simply checking the brake works manually does not mean it will come on by inertia action... and vice versa

Ian