Does the pelvis/the hip bones spread with age?

May 28, 2006 7:18 AM

Anyone have medical/anatomical knowledge to support the observation that the pelvic girdle/hips grow wider as a person ages? I don't mean getting fat - I mean literally do the bones spread outwards, increasing the hip size and so the width between the legs. I see this on old men especially
posted by A189Nut to Health & Fitness (4 answers total)

Perhaps it simply looks like the bone is widening because older men lose weight and/or muscle in their legs as they age and stop exercising as much. Skinny legs make the pelvis look wider.
posted by underwater at 7:55 AM on May 28, 2006

All bones grow in diameter and "hollow out" at the center as humans age. Basically your body is constantly laying down new bone, mostly at the outside, and reclaiming parts of the bone, mostly from the inside. The inside of the bone ends up spongy and weak, while the outside has most of the structural strength. Old people look like they have large fingers because... they do.
posted by jellicle at 8:47 AM on May 28, 2006

If this were true then I would expect to have heard about it as a method for aging/sexing skeletons in forensic or archaeological cases. There are undeniable osteological changes associated with aging, in particular, bones tend to lose mass, become more porous, exhibit more osteoarthritis, there will be ossification in certain areas and bone loss in others, etc. Bone loss is probably even more pronounced in sedentary, westernized people. The pubic symphysis is the classic locale of aging pelvises. The main aging-related effect of changes in bone remodelling that jellicle alludes to is a loss of bone density, not so much diamter changes. I am not aware of changes in pelvic width (remembering the pelvis is actually made of three separate bone elements per side: illium, ischium and pubis and may not react as a single entity). You might find something of interest on this page of osteology lecture notes (semi-self link) and/or here

If I had to guess, I would suggest the answer to your question iis more related to underwater's suggestion of changes in fat or muscular overlay in the elderly giving the appearance of more distance between the legs. I'd hazard a guess that changes in posture related to spinal conditions might also affect the pelvic alignment to the same visual effect, but thats a pure guess
posted by Rumple at 10:43 AM on May 28, 2006

Childbirth also permanently expands the pelvic bones... or so my nursing instructor told me. (I didn't finish nursing school - wasn't my cup of tea.)
posted by IndigoRain at 9:04 PM on May 28, 2006