Engineer Georgena Terry has been designing women specific bicycles for for thirty years. Twenty-five years ago my wife and I both rode her classic Butterfly saddles, an expensive $60 at the time, on our tandem, and I found that saddle design fit me better than the racing models available, and for years I rode Terry saddles on all my bikes. I wonder what that says about my butt anatomy? Butt that is another story. What I would like to share with you is her four minute video discussing flat bars versus drop bars.
Master age riders who do not maintain spinal flexibility in their cervical, thoracic, or lumbar regions may still find cycling comfort with a bit of bar, stem, and spacer research, to wit the following informative video. Ms. Terry makes valid efficiency points for curved or drop bars; however, most master age avid riders eventually become more concerned with comfort on our bikes versus racing or ergonomic efficiency.
If you are one of us who prefer comfort over speed these days, a couple viewings will give you food for thought. Her example body angle using the same bicycle cockpit length from the horizontal are:
Flat bars spine approximately 52 degrees
Drop bars hands on bar top spine approx. 47 degrees
Drop bars hands on hoods 44 degrees
Drop bars hand in the drops 31 degrees
Four or five degrees may not be much of an adjustment for our 12 thoracic vertebra; however, even two or three degrees do make a discernible difference to only 7 cervical vertebra vis-a-vis supporting 10 pounds of skull and brains, eyeballs, tongue, teeth… as much as 8 to 10 percent of our body weight. Think of it this way. The most comfortable head position is balanced on the spine with eyes looking straight ahead. As the spine angle changes our six very small ocular muscles quickly become strained when the eyes are continually rotated from the level position; ergo, cervical muscles compensate to keep the eyes in a level position. Herein rests the compromise decision between flat and drop bars for master age riders. https://youtu.be/fNNWH2C-Muc