{"id":7993,"date":"2026-10-17T20:31:49","date_gmt":"2026-10-17T18:31:49","guid":{"rendered":"https:\/\/blueportance.com\/knowledge-base\/questions\/weight-distribution-sitting\/"},"modified":"2026-10-25T22:49:50","modified_gmt":"2026-10-25T21:49:50","slug":"weight-distribution-sitting","status":"publish","type":"page","link":"https:\/\/blueportance.com\/en\/knowledge-base\/questions\/weight-distribution-sitting\/","title":{"rendered":"How is your weight distributed when you sit?"},"content":{"rendered":"\n
\n

Knowledge Base<\/a> \u2192 Questions<\/a> \u2192 How is your weight distributed when you sit?<\/p>\n\n

How is your weight distributed when you sit?<\/h1>\n\n

Mainly on the sit bones, the buttocks and the back of the thighs; depending on posture, also on the perineum or the tailbone. A good seat does not remove pressure: it spreads it over areas that tolerate it, avoids hard spots and lets it shift. Removing one contact area always moves its load somewhere else.<\/strong><\/p>\n

Where does the weight go?<\/h2>\n\n\n\n\n\n\n\n\n
Area<\/th>\nRole<\/th>\nIf it is overloaded<\/th>\n<\/tr>\n<\/thead>\n
Sit bones (ischial tuberosities)<\/td>\nMain bony contact points<\/td>\nA painful point, burning<\/td>\n<\/tr>\n
Buttocks, back of the thighs<\/td>\nSpread the load<\/td>\nNumbness, diffuse pain<\/td>\n<\/tr>\n
Perineum<\/td>\nShould carry very little<\/td>\nPain, irritation of the pudendal nerve<\/td>\n<\/tr>\n
Tailbone<\/td>\nBottom of the spine<\/td>\nPain on contact and when getting up<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Why spread the load?<\/h2>\n

For the same weight, a larger contact area lowers the average pressure; and pressure that moves is better tolerated than pressure that stays in the same place.<\/strong> Pressure in the small blood vessels of the skin is low (Landis, 1930<\/a>): concentrated, prolonged contact easily exceeds it.<\/p>\n

What happens when you remove a contact area?<\/h2>\n

A central cut-out shifts weight onto the sit bones and the edges; a rear cut-out shifts it forward; a soft seat lets you sink in until you touch.<\/strong> This is why the area that carries the weight matters as much as the one you free up.<\/p>\n

What if your sit bones hurt?<\/h2>\n

Check that the load stays well distributed around them, without giving up the offloading another area needs.<\/strong> Among the configurations that keep the necessary area free of contact, the Aporia framework looks for the one that keeps the most continuous support around the painful sit bone. A central or rear cut-out leaves the sit bones supported on either side: check that it does not increase the load on them; a continuous channel brings them closer to its edges. If no area needs to be kept free of contact, continuous support (Aporia Standard<\/a>) is the reference. The conditions related to your contact points, your seat and how you use it are in the guide Which cushion for pudendal neuralgia?<\/a><\/p>\n

Should a cushion be soft or firm?<\/h2>\n

Neither, as a rule: the support should keep its shape under load without hard spots.<\/strong> Firmness is chosen according to your sensitivity, not your weight.<\/p>\n

What other questions do people ask?<\/h2>\n

Should the sit bones carry all the weight?<\/strong> No: the buttocks and thighs should share it.<\/p>\n

Does a thicker cushion spread the load better?<\/strong> Not necessarily: it can destabilize the pelvis and change your seat height.<\/p>\n\n

\n

Publisher: Blue Portance. Written by Gil Ayache, PhD (Mines Paris \u2013 PSL). Reviewed: October 19, 2026.<\/em> Sources: Landis E. M., Heart, 1930 (capillary pressure), cited in the Blue Portance reference framework; Aporia framework (sit bone rule of the V16 engine).<\/em> Aporia\u00ae cushions are not medical devices.<\/em><\/p>\n

Note:<\/strong> this content explains mechanisms related to sitting. It is not a medical diagnosis or prescription, and it does not replace the advice of a healthcare professional.<\/p>\n<\/div>\n