As we groan and push ourselves away from the Thanksgiving table today, heading into the six-week food fest that is the holiday season, there is an instant way we can look and feel as if we've lost 10 pounds: by using good posture. Yes, as much as we hate to admit it, Mother was right when she admonished us to "stop slouching and stand up straight."

Not only does poor posture make us look fatter, it can be detrimental to our health. Slouching often leads to back pain, impingement syndromes, and strained ligaments and muscles. If poor posture persists, it can, as we age, lead to curvature of the spine.

Good posture results in a strong, healthy spine. It also shows confidence. There's a clear mind-body connection between our posture and our inner selves.

We spoke with certified personal trainer Stephanie Lay, who is offering a free clinic on Dec. 12 (see box) about posture issues.

Lay said you can actually trick yourself into feeling more confident just by using good posture. "You need a sixth sense of your body to make sure it's all in line," she said.

She offered a visual cue to keep in mind: Your ears, shoulders and hips should be in perfect alignment, as if a plumb line could be dropped straight down through them.

Good posture should, of course, feel natural. However, many of us have used poor posture for so many years that our bodies are no longer familiar with the feeling of good posture so it might feel weird at first. Stick with it.

Stretching and core exercises (yoga and Pilates come to mind) can help by strengthening the lower abdominal muscles and back muscles that support the spine. Lay, along with other experts, insists that it's never too late.

CHECK YOUR POSTURE

GOOD POSTURE, STANDING

1. It should feel as though you're loosening everything in front and tightening everything in back, Lay said.

2. Core (lower abdomen) and buttocks pulled in.

3. Shoulders down and back, chest held high.

4. Head should feel tucked down slightly, like you're making a double chin.

5. Pull your head back and up as if to flatten your neck against a wall.

6. Feet and knees hip width apart, with knees relaxed, not locked.

GOOD POSTURE, SITTING

1. Back, shoulders and upper back muscles relaxed.

2. Both feet resting flat on the floor with knees level with hips.

3. Head, shoulders and hips in line.

4. Tuck in your chin slightly.

5. Keep your shoulders relaxed, not pulled up toward your ears, rounded or pulled backward.

6. Sit with your back firmly against the chair. If your chair doesn't give you adequate support, try a small pillow or towel behind your lower back.

TAKE THE WALL TEST

Lay offers this exercise to test your posture: Stand with your head, shoulder blades and buttocks touching the wall, with your heels about 2 to 4 inches from the wall. Open your arms to the front, with backs of hands against the wall. Next, turn one hand with palm facing the wall. Reach back and slide your hand behind the curve in your lower back, with your palm flat against the wall. There should be about one hand's thickness of space between your back and the wall. If there's too much space, tighten your abdominal muscles to flatten the curve in your back. If there's too little space, arch your back so that your hand fits comfortably behind you. Walk away from the wall maintaining this posture.