Good posture means that the spine is in a neutral position (not bent forward, backward, the side, or rotated). It is a position where there is the least amount of stress on the joints, ligaments, and muscles, keeping you balanced over your feet. It is also the healthiest position for your entire body. Having good posture can help to maintain balance, and prevent fatigue, joint and muscle strains, neck, mid-back and low back, and even shoulder and arm pain. Good posture makes it easier to move, makes you feel more confident, and probably more attractive. 

Unfortunately, poor posture is fairly common. Sometimes it is caused by the way you sit, lack of exercise, the way you move throughout the day, and of course, poor posture is a common age-related change. One of the most noticeable changes that occurs with aging is a rounding of the upper to mid back, this is called kyphosis. It can be caused by osteoporosis, but also by just normal wear and tear on the joints because of poor habits. A curved upper back moves the head in front of the base of support (center of gravity). A forward leaning, or slouched posture will shorten the muscles on the front of the hips (hip flexors - iliopsoas and rectus femoris) and torso, and lengthen the muscles on the back of the torso and hips. To adjust for these changes, during walking, the legs do not move back as far (limited hip extension). If the leg is not moving back behind the body, the hip joint gets tight. This can lead to shorter steps and slower walking speeds. The gluteus maximus is an important muscle for holding us in good upright posture, if the muscle weakens then our posture gets worse - this can lead to a progressive downward spiral. The good news is that this can be prevented or slowed by doing the right exercises with good form.

There are other exercises that are done in standing that will work the gluteus maximus - like lunges, squats, and deadlifts. But those exercises focus on pulling the hip back from a flexed position to neutral. Standing Kickbacks are one of the few exercises that work the leg from neutral and back into extension. This is a really good way to learn how the hip moves back behind the body, this will help to keep the hip joint mobile and the gluteus maximus strong. 

It should be noted that the hip should move back behind the body when you are walking, but when you are walking on level ground, this movement does not require much muscle activity. When you are walking uphill or running the gluteus maximus is more active. The goals of the standing kickbacks are to move the hip into extension and to try to isolate the gluteus maximus muscle for strengthening while holding the spine in neutral.