research on saddle angles and LBP (=lower back pain)

[Faye]

Curious if anyone has thoughts on this (notwithstanding the small N, typical of studies in medicine, and the lack of controls). ... would you consider inclining the anterior of the saddle at all? To an extent we probably expand the angle somewhat on our own by sitting more upright with hands on tops instead of hoods when climbing, but curious if folks have thoughts since I for one have lots of LBP secondary to cycling:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1756210/pdf/v033p00398.pdf

(Abstract: OBJECTIVE: According to the literature, 30-70% of cyclists suffer from cervical, dorsal, or lumbar back pain. This study was conducted to evaluate one of the possible causes of low back pain and to suggest a solution by appropriate adjustments to the bicycle. METHODS: Serial fluoroscopic studies were performed while cyclists sat on different types of bicycle (sports, mountain, and city). Pelvic/spine angles were measured at different seat angles, and the related force vectors analysed. RESULTS: There was a tendency towards hyperextension of the pelvic/spine angle which resulted in an increase in tensile forces at the promontorium. These forces can easily be reduced by appropriate adjustment of the seat angle--that is, by creating an anterior inclining angle. The findings of the biomechanical analysis were then applied to a group of cyclists who were members of a cycling club and who complained of low back pain. After appropriate adjustment of the saddle angle, most of the cyclists (>70%) reported major improvement in the incidence and magnitude of their back pain. CONCLUSIONS: The incidence and magnitude of back pain in cyclists can be reduced by appropriate adjustment of the angle of the saddle. It is important that these findings be conveyed to cyclists, bicycle salesmen, trainers, and members of the general public who engage in cycling, in order to decrease the prevalence of back pain.)

[Aaron Hicks]

Yes, try it!  Have you thought about altering the angle or length of your stem?

I had a possibly similar experience back in 2007, when I got a new hard tail mountain bike, and I found experimenting with the seat angle was a very useful exercise.  I haven't seen this article before, but I remember reading https://www.sheldonbrown.com/saddles.html (specifically the section "Angle") and asking everyone about my lower back pain.  I tried a wide range of angles and found quite a few positions that seemed uncomfortable and eventually settled very close to horizontal.  I didn't think to measure the angle where I started(perhaps you could though), so it's entirely possible I eventually settled on the original configuration, but after trying at least a dozen adjustments over the course of a few weeks, I did eventually settle on an angle that felt best.

In addition to adjusting the seat angle, I slowed down on increasing my weekly mileage, adjusted the angle of the stem, did lots of crunches, pull ups, and even threw in some swimming.  I don't know what exactly fixed the LBP, but I haven't needed to adjust the angle of my saddle since then, so at the very least, I didn't break the bike by fiddling with the seat.  Sheldon Brown's summary of ""You never know what is enough, until you know what is too much." has really helped me in experimenting with bike fit.

[Paul Chomsky]

10-15 degrees angled forward???  would improve life for 70% of the cyclists??  I find this unlikely.  How didn't they start having shoulder pain instead?

I presume you already tried other things like "conventional" bike fitting and strength training, so why not try the angle.

Otherwise, I'd think that saddle angle should be the last adjustment to try, after setting saddle height, choosing the right width, shifting saddle forwards/backwards, selecting proper stem length/height etc.  Especially saddle width: I'd think the most immediate effect of angling the saddle forward would be that the biker shifts forward and downward, effectively decreasing saddle width and height.

On Sunday, September 17, 2017 at 2:42:14 PM UTC-7, Faye wrote:

[faye steiner]

I'm not sure if I would adjust my saddle angle, I was just mostly curious what people thought of this idea and if you have ever heard of adjusting a saddle angle in this way, because I had been under the impression that it was generally advisable to have your saddle totally level.

As for me, yes, I had an excellent bike fit (albeit in 2011), and I am with you Aaron, that strengthening abs definitely helps the lower back. After my lap appy (that's laprascopic appendectomy for the non medicine folks 😊  ), once I was allowed to ride again, I literally could not sit up /support myself sitting up adequately on the bike and my entire lower back was super painful in ways I have never experienced.  (Now that I have scrubbed into a whole bunch of lap cholys and lap hernia repairs, I understand why I had such a long recovery and it took so long to get my abs back, though, I will say, you're still slashing and burning a lot of the abdominal wall and fascia and tissue).  It was really getting my abs back that resolved that pain.  Other than that, I don't have super bad LBP and the pain I do have mostly comes from my hip and SI joints. But I am always curious about these kinds of ideas since the general position that we're forced into on roadbikes (even with a nice comfortable recreational fit) doesn't seem really ergonomically advisable to me.  

On a somewhat related note, one thing I wonder about is if your saddle gets compressed if you have used it a lot- like if you have used your saddle for riding 8k miles a year for 5 years, would it be compressed to the point that your seat height is not what it was when your bike was first fitted, and would it therefore make sense to raise your seat a couple of mm?

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[Paul Chomsky]

> if you have ever heard of adjusting a saddle angle in this way

I've never heard of it.  But it's awesome that you're keeping your mind open.

I've never owned a saddle for that long so I can't tell.  The only thing I know is that leather saddles are expected to sag with time; they usually have special screws to stretch them back on a bit.