The Dana Design Shortbed ($279; www.danadesign.com) was a revelation when it came out about five years ago. An external-frame pack from an internal-frame pack company, it really combined the best of both worlds: the good flex and balance of an internal frame with the ventilation and packing options of an external frame. Alas, it and the other external-frame models are no longer in the Dana lineup. Earlier this year I got a Terraframea Shortbed frame with a Terraplane bagfor $99. They were close to $300 new.
Anyway, this isn’t answering your question. You don’t say how much you were carrying. A lot? As in, 60 pounds or more? As my old high school biology teacher Bill Oberteuffer once said, slumping to the ground under a loaded Kelty pack (back when they were da bomb) during a school-sponsored hike: “There’s no magic in any pack if you overload it.” So big loads will tax any pack. And ten miles is a pretty long march, so I’d not be surprised to see my own hands swell up a little.
Otherwise, it could be a little tight around the shoulders. You can always just loosen the shoulder straps to put a bit more weight on your hips. Or, spend some time adjusting the pack with the idea that you want the curve of the pack straps further up the frame, for a greater distance between hipbelt and shoulder straps. And, of course, it never hurts to sit down every hour or so and take your pack off. Have a nice drink of water and enjoy the surroundings! That’ll help solve a lot of pack problems.