(CNN) -- As you cradle your smartphone or lean into your laptop to read this, what's your posture like? Even if you aren't doing it right now, how much of your day is spent with your neck lurched forward, shoulders slumped and chest collapsed? All that time in "smartphone slump" not only makes you look and feel stressed, it can cause persistent pain.

Although slouching might seem like a lazy posture, it actually takes a lot of dysfunctional muscular effort. Because evolved humans aren't designed to hold an upper-body slump, many of your neck, chest and back muscles are recruited out of their primary positions to pull your head and shoulders forward. This causes a chain reaction of other muscles throughout your body picking up the slack and doing jobs they weren't designed for in order to hold and move your skeleton in a slouch.

Understandably, those chains of overworked, out-of-place muscles cause a lot of problems, from neck and back aches to migraines, limited range of motion, decreased strength, increased risk of injury and more. That's why stretching alone isn't the answer. You need to retrain and realign your muscles to function as intended to support proper posture.

Your smartphone is a pain in the neck

Practicing these six yoga poses several times per week will provide the right combination of stretching, strengthening and realigning to relieve tension and avoid slipping back into smartphone slump the next time you scan social media.

Cobra

This yoga pose stretches the front of body, including the chest, shoulders and core, while strengthening and realigning neck and back muscles.

Lie on your stomach with your hands next to the middle of your ribcage. Use your mid-back muscles to guide your shoulder blades and elbows inward. Inhale as you lift your chest and roll your shoulders back and down. Keep your head and neck in line with the arc of your spine and maintain a bend in your elbows as you press through your palms like you're trying to slide your lower body forward through your arms. This action lengthens your lumbar spine (low back) and broadens your collarbones and upper back.

Take three long, deep breaths. Exhale to release. Repeat three times.

Kneeling lunge with reach back

This pose stretches the chest and enhances mid-back strength and mobility. It also is a good hip flexor stretch.

From a kneeling lunge with your left foot forward, place your right hand on the outside of your left thigh. Inhale as you reach your left arm behind you with your palm up, turning your head so your gaze follows your hand. Engage your core and back-leg hip and glute (butt) muscles for stability. Keep your forward knee aligned above your ankle. Be sure the twist is coming from your mid-back -- not your low back.

Hold for three long, deep breaths. Repeat on the other side.

Locust variation

The locust variation strengthens the core, back and neck muscles while opening the chest.

Lying face down, engage your core and back muscles to lift your upper body. Reach your arms back along your sides with palms up. Use your mid-back muscles to draw your shoulder blades in and down. Keep your head and neck in line with your spine. Your legs and feet should remain on the floor in this variation.

Hold for three breaths. Repeat three times.

Turn signals

This pose strengthens the core, back and neck muscles while restoring shoulder girdle function and alignment.

From locust pose, reach your arms out with your elbows bent to 90 degrees. Inhale as you sweep your right arm forward and under your left arm. Exhale to return it to 90 degrees. Inhale to repeat the movement using your left arm. Alternate your arms with your breath six times.

Supported fish

This pose opens the chest, front of neck and shoulders.

Lie back with a yoga block positioned under your mid-to-upper back so that your chest is lifted and your neck and head drop back comfortably. If dropping your head back is too extreme, practice the modified option with your entire back, neck and head resting on a bolster or firm pillow. Place your arms out to the sides and release your chest, neck and shoulders. Stay in this pose five to 10 long, deep breaths.

Savasana/Corpse

Relax overworked neck, jaw, upper-back, chest and shoulder muscles with savasana or corpse pose.

Without anything propped under your head, lie flat, letting your head, neck and back relax into the pull of gravity. Release your jaw by positioning your tongue behind your top teeth. Close your eyes and take at least 20 long, deep breaths in and out of your nose.