No, a healthy person doesn't need to stretch their back every day. Gentle daily stretching is acceptable if it's enjoyable, pain-free, and helps maintain proper mobility, but there's no evidence that daily spinal stretching is essential for back health, pain prevention, or "correct posture."
Yes, for most people, swimming and other water exercises can be beneficial for joints. Water reduces the impact of body weight on weight-bearing joints, making the activity often easier to tolerate than walking or exercising on land.
For most people with normally functioning knee joints, casual running is not considered a cause of "wear and tear" on the knees and is not associated with an increased incidence of knee osteoarthritis.
After standing for a long time, legs often become tired for two related reasons: muscles are forced to hold the body in almost the same position for a long time, and venous blood flow from the legs is less efficient than during walking.
There's no universal medical threshold beyond which standing becomes harmful. It's impossible to say that a healthy person can safely stand for exactly 30, 45, or 60 minutes, but the next minute causes damage.
Regular movement is generally beneficial for joints: it maintains muscle strength, mobility, coordination, and the joint's ability to withstand everyday stress. The idea that every step, squat, or run gradually wears down articular cartilage is overly simplistic.
The back often gets tired when standing for a long time because a stationary vertical posture requires long-term low-intensity control of the muscles of the trunk, pelvis, and legs, and the same structures remain in approximately the same position for a long time.
For long walks, the most important thing isn't the brand of shoe or the "for walking" label, but the proper fit. A good pair should leave enough room for the toes, provide heel support without slipping, fit securely around the midfoot, avoid any pressure points, and feel comfortable from the moment you try them on.
