Hi Deb.

I am not sure how familiar you are with forklift operation.

If you are really only trying to help others then maybe I can be of assistance to you.

Firstly is this " Strain " only on the left shoulder and is there any possibility that it is really Neck related ?!!!.

Think about that and then I will give you some "Possible" leads.

I say that because if operators were driving properly I think, like the other respondents, that the shoulder strain is unlikely to be related to the " Spinner " which should be held Palm down and despite your obvious technical knowledge does not materially increase muscle strain ( in some cases it could decrease it ) That will depend on the positioning the wheel, seat and foot pedals.!!!!

Please accept I am not trying to doubt your obvious knowledge on this matter.

Rgds

deb l

I think you will find taht the lock to lock ratio on most sit down rider units will be in the area of 3.5 turns with power steering units. When you get into heavery lifts above 10k capacity the ratio will increase somewhat - you don't want to have the big units spinning on a dime (or a 6 pence) and "nudging" something - especailly with the NASCAR wannabee type drivers too often found in the seat of a lift truck

Years ago when manual steering was around steer ratios were about 6.5 turns lock to reduce steer effort - but like the Peter & Gordon song goes "That Was Yesterday & Yesterday's Gone."

Hi finn - thanks - yes I think there are lots of people out there doing many hours on forklifts.
Thanks for your other responses
Johnr - yep - guess I would need to go to individual specs - I didn't think it was ethical to start mentioning manufacturers - agree that force application is a risk factor but as stated the new machines have addressed this - I believe rotation reps however are a big risk factor. This does not appear to have been addressed ie lock to lock rotations.
Normandy you mention training - does this talk about posture/ duration of time spent on forklift each session? I would very much appreciate if you could point me towards this training.
I am a Physio and ergonomist and my job is to alter injury cause -no litigation here - just trying to help people - despite you not being aware of shoulder symptoms related to forlift operation I can assure you that they happen.
TC17 you mention the spinner **** - this puts the hand in a palm down position which puts the forearm muscles on stretch and adds another risk factor - a better design would be a bar or pistol grip. The overall risk however would still be dependent on how long the person operates / job demand and so on.
Going back to my original question - lock to lock ratio -
thanks again for your responses.

Hi Deb
i drove container forklifts and usually do up to 65 hours in a 5 day week, i know it,s a lot and i felt the effects,but i don,t mind.
i have at some stage felt a repeditive strain on my right shoulder as the machines i used have a lot of control functions on the right side like over 20 of them and only a few on the left,it comes with the job.
there are some machines with joystick steering but it would not make any difference to r.s.i.
the spinner makes no dif to me.

I agree Normandy. I have never heard of anyone developing shoulder strain from using steering forklifts, especially how easy they turn and our lifts have spinner knobs, which in my opinion makes it that much easier. (I know there are people out there that do not like the spinner knobs, it is just something that I like).

If Operators used the methods explained in training this would never be a problem,

Sounds like some smart lawyer is trying to make a claim with smoke screens.

No Modern truck FROM ANY MANUFACTURER would cause this issue if driven properly.

1. What type of truck or trucks are you talking about?
2. Most important to teh operator is the effort required at the rim of te hsteering wheel or the handle on a tiller.
3. Most manufactuers try to reduce the number of revolution from lock to lock. On sit down rights msot are in teh neighborhood of 3.5 turns lock to lock. But it will very from company to company. Sometimes thsi info is published in product literature/spec. sheets - searching the websites for various companies might give you soem data.
4. Don't know any data sheet that list all companies or data. on this issue.

Sounds like you are gathering data for use by a legal counsel or similar group