Lately I've been getting sore shoulders too. Wasn't sure if was cause of the wider handlebars or not. I ride with the seat on the second to the last reclined position which seems to be decent enough to cut through the occasional head & cross winds.
Have been trying to let up on holding the handlebars, although have to brake-steer around obstacles here. Many places the sidewalks have angled-surfaces to allow vehicle traffic in which make me ride on an angle.
Thinking perhaps of repositioning my back on the standard seat and trying to regain center on the angled or leaning sidewalks might had something to do with it.
I've got a seat wedge to help me from scooting forward but it seems I still do slide forward and reposition my back at times - more subconsciously.
I could try going back up a notch which could alleviate the pressure of the seat from gouging the back of my thighs - especially the right thigh, although would mean having to scoot the seat back more. Am concerned with the crosswinds and such again.
For some reason laying back seems more of a comfortable ride with less pressure on the thighs (left mainly). Yet after some rides the shoulders ache some. Not painful, but can feel it a few hours after the ride.
When I went down the Weiser River Trail both the shoulders and forearms were in pain the following night. Took some Tylenol to get back to sleep. But half way through the ride I had to raise the seat up a notch to relieve the thigh pressure, yet that position threw my legs closer to the pedals and there was argument from the right knee. But I got through okay.
Thing is I'm never sore during the ride, it's only a few hours after, at night, or the next day when the shoulders feel slightly sore.
Wondering if perhaps it's that I bounce and move around so much in the seat that causes this. Always compensating for changes in the riding environment.
Would like to know if the wider seat would help or not, as was told the seat is only an inch wider on each side. Unsure if the seat would be any longer or taller.
Would of thought by now my shoulders would of gotten used to trike riding, though I've been riding more lately than I was able to last Fall before that horrible winter hit.
And my shoulders ache too from pushing carts of chips around at Walmart too. Guess is something one cannot cure.
Unsure if a lumbar support would work. Wished I could somehow borrow a wider seat to see if it would work cause that's a hefty investment if it does not resolve the issues.