What Are the Signs That Your Core Muscles Are Weak?

When you hear anyone refer to your core, you no doubt think of your abs — or at least some other guy or gal's enviable six-pack.

While weak abdominal muscles play a role in overall core strength, other muscles make up this area of the body as well. The muscles of your lower back, glutes and even hips contribute to core strength, too. Any weakness in these muscles can bring about a number of problems and issues.

Poor posture is often an indication of a weak core. The muscles that make up your abdomen and lower back help to stabilize your pelvis and spine, keeping your upper back and shoulders in a neutral position. Over time, poor posture can contribute to neck and back pain, headaches, poor balance, breathing difficulties and other complications.

If your abdominal and back muscles lack strength, especially when it comes to the erector spinae, a group of muscles that run along your spine, you're far more apt to slouch. In fact, lower back pain is another good indicator of weakness in your core muscles.

When your core isn't as strong or balanced as it should be, the curvature of your lumbar spine can change. Even the slightest difference can place undue pressure on the vertebrae, discs or articulate facets that make up your spine, as well as the muscles, tendons and ligaments that surround it, making you more prone to injury.

Read more: Exercises for Strengthening the Core & Lower Back

One perhaps surprising sign of a weak core is digestion issues. A weak core and digestion can be related if you have a slouched posture, especially after a meal.

When you have poor posture, it may to lead to heartburn caused by acid reflux. Dr. Kyle Staller, a gastroenterologist at Harvard-affiliated Massachusetts General Hospital, told Harvard Health Publishing that slouching can put pressure on the abdomen and force stomach acid in the wrong direction, into the esophagus.

Poor posture and a weak core can also lead to constipation if you're not sitting upright while on the toilet. When you sit hunched over, your knees may drop lower than your hips and close the anus somewhat. In this position, it's harder for your abdominal muscles to contract and complete a bowel movement. By strengthening your core, you'll more easily be able to sit upright and maintain proper posture both in and out of the restroom.

Read more: Can I Work My Core Every Day?

Overall weakness is also a sign that your core muscles are weak. This weakness, however, doesn't need to manifest from the core itself. Instead, weakness in your arms and legs can indicate a poorly conditioned core.

As the muscles of your core stabilize your spine and pelvis, it's this stability that helps transfer the strength needed to rapidly contract the muscles for more powerful movements. Throwing a ball, landing a punch or taking a forceful stride all originate — at least to some degree — from your core muscles. If this area isn't in condition, there won't be as much strength behind your movements.

Another potential sign of weak core muscles is the inability to hollow your stomach. Try it, and see if you can do it: Take a natural breath, and, as you exhale, pull your belly button in toward your spine. Hold for a count of 10, then release. If you were unable to sustain the hold for the entire count, this is a good indication of a weak core.