Efficient movement is truly an art. In sports, it's called "good form." But to us non-jocks, trying to get something done in the kitchen, garage, or garden, it's simply called "good body mechanics."
Many people have come to believe that a shoulder-width stance is the ideal stance for almost every activity. Maybe this is related to the number of personal trainers and therapists who advise people to exercise with their feet shoulder-width apart, or maybe it's just been repeated so often that very few people question it. The problem with this belief, though, is that without the feet wider than shoulder-width apart, bending your knees won't help much. Especially not during lifting.
Try this experiment in lifting a light object:
1) Place something light--maybe a pen--on the floor in front of you. Stand with your feet only shoulder-width apart, then bend your knees and pick up the pen.
2) Next try the same thing with your feet wider than shoulder-width apart. The first thing you'll notice is, the farther your feet are apart, the lower you are and the closer you are to the pen. The second thing you'll notice is, you don't have to reach over your knees to get to the silly thing. You can basically straddle it, right?
See how the wider than shoulder-width stance gets your knees out of the way? Feel how it lets you bend at the hips more easily? See how the guy in the second diagram looks more balanced? That's because he is more balanced. (His lower back looks better-aligned too.)
If the wider than shoulder-width stance were only good for lifting things, maybe I wouldn't be quite so in love with it. But this trick is good for lots of things! It even comes in handy with hateful chores like doing dishes.
Here's an experiment to try in the kitchen:
1) Bend and touch the bottom of the sink with your feet merely shoulder-width apart. Make a note of how this feels.
2) Now bend and touch the bottom of the sink with your feet wider than shoulder width apart. Which feels better? Multiply your "better feeling" by the number of times you reach into the sink while doing dishes.
3) Now try reaching into the sink with your feet only shoulder-width apart, and place an imaginary dish into the dish drainer (or dish washer). How much twisting in your spine was required. How much of your body did you use to complete the movement?
4) Now, switch to your super-wide stance. As you put the dish into the drainer or dishwasher, shift your weight onto the leg closer to the dish drainer and bed the knee slightly. What's different? How much twisting did you spine have to do with each method? How much of your body did you use to complete the movement?
Look at the photograph of the woman in a martial arts stance, you can see that her feet are wider than shoulder width apart, and she has shifted her weight to one leg while maintaining good spinal alignment. Can you see the use of this movement in the practice of doing dishes?
Tai Chi classes help you learn to use your body naturally like this. When your entire body synchronizes to complete a movement (instead of just segments of it), you'll be more balanced and less likely to injure yourself.
Your spine will definitely thank you.