In the early 19th century, many men wore corsets to support their backs, as well as to give them shapely waists. They found that this could improve their working stamina because they did not cause pain to their backs from bad posture. Soon after, women began to use the same technology, for the same reasons. Men rapidly stopped using it, not because it did not benefit them, but because they feared being accused of being effeminate.
Today, many people wear elastic back braces that are almost (but not quite) as effective as a good boned corset. Some people who have heavy lifting jobs wear them to prevent injury. Other people who have injured themselves wear such braces to protect their injured backs.
But all of this pales in comparison to having a strong back and core. For people with that, they have health without the need of any technology at all.
I’m going to disagree withabout very straight posture. The current medical majority opinion is that it is better to have gentle curvature in three phases: lordotic (forward) curve in the neck, kyphotic (backwards) curve in the upper back, and another lordotic curve in the lower back. However, new cutting edge research tells us what our ancestors already knew: this is bullshit. The healthiest people (as measured by how few of them have any pain, their stamina, and their strength) have almost no curve of any kind in their spine, until their bottom few vertebrae, which curve backwards. (Not a kyphotic curve, because this one is one-directional. The sacrum is farther back than the rest of the back.) A few remaining primitive tribes have this, and many old portraits and sculptures show this. The idea that the three-phase curve is healthy was invented to make unhealthy people feel good about themselves.