Research supporting the position that posture affects longevity.

It will take decades for tight double blind studies to happen along the lines of the Framingham study (which demonstrated that exercise is good to live longer, but phase I of the well funded study took from 1948-1998).  However, in the meantime the commonsense advice of mom's and trainers everywhere is supported by Kado's stud 2004 and followup studies in the Annals of Internal Medicine,  Hyper-kyphosis predicts mortality independent of vertebral osteoporosis in older women (2009) and Narrative Review: Hyperkyphosis in Older Person(2007).

Their conclusions:  "many older adults who are most affected by hyperkyphosis do not have vertebral fractures. Hyperkyphosis may be independently associated with an increased risk for adverse health outcomes, including impaired pulmonary function, decreased physical function capabilities, and future fractures".

The correlation was between the observation and mortality...the mechanism being cardiopulmonary compression is their conjecture (and is in all likihood true, but that has not been researched...and probably wont be in the next few decades, as I cannot think of a way to build an effective control).  My personal feeling is that balance degeneration causing falls causing decreased activity/increased diabetes is also a factor.

Regardless, one of the differences between research and clinical is in clinical we should be aligning our actions with what is most likely to benefit, even if that cannot be definitely proven.  My ongoing conviction is that posture strengthening and chiropractic helps people to age more successfully by keeping them active and managing pain thru mechanical (as opposed to pharmacologic) methods.

Hyperkyphotic Posture Predicts Mortality in Older Community-Dwelling
Men and Women: A Prospective Study
Journal of the American Geriatrics Society
Volume 52 Issue 10 Page 1662  - October 2004
Deborah M. Kado, MD, MS, Mei-Hua Huang, DrPH, Arun S. Karlamangla, MD, PhD,
Elizabeth Barrett-Connor, MD and Gail A. Greendale, MD

Ann Intern Med. 2009 May 19;150(10):681-7.
Hyperkyphosis predicts mortality independent of vertebral osteoporosis in older women.
Kado DM, Lui LY, Ensrud KE, Fink HA, Karlamangla AS, Cummings SR; Study of Osteoporotic Fractures.