If you’re a regular gym goer, it’s easy to get stuck in the habit of thinking about each muscle in isolation, and working them that way. But this approach causes muscle imbalances: When demands placed on one muscle are too heavy to bear, another less suitable muscle will take over to support the weight. In some situations, the opposing muscle compensates and becomes stronger than its counterpart, meanwhile your weaker muscles remain weak.

One way to prevent muscle imbalances — and get better results when you work out while also preventing long-term injury — is to think of the body as a system with complementary muscle groups. And complementary muscles are often involved in the same movements so it makes sense to work them together.

But before you try that, it’s important to know the muscle groups that are often weaker. These are some of the most common areas of muscle weakness. Check them out, and take note. After all, you’re only as strong as your weakest muscle group.

1. Glutes and Hips

The glutes and hips are some of the most common weak muscles. Inactivity from sitting is often the culprit. Gluteal weakness impacts lower body strength, and it’s particularly noticeable during a squat: When the glutes aren’t strong enough to hold your body weight during the lowering movement, the lower back and hip muscles compensate for that weakness. The hip flexors may also try to kick in to balance the body and deepen the squat causing a forward lean and, ultimately, over-activation and injury.

2. Forearms

While easily overlooked, the forearms aren’t a muscle group to ignore during strength training. Forearm strength determines everything from your grip on the weights to how much weight you can lift. Believe it or not, weak forearms and wrists impact how hard you can work your arms, upper body, and even your back.

Without forearm strength you won’t be able to max out the larger upper body muscles because your forearms will tire first. For example, any back exercise requires grip strength. Now, imagine your back is strong enough to get to 10 pull-ups, but your forearms are fatigued after five reps. Because of your forearm weakness, you are unable to push the muscles of the back to their limits.

3. Abdominals

The Top Weakest Muscle GroupsThe abdominals work together with the lower back to balance and stabilize the body. The effects of a weak core can be felt from head to toe, manifesting in everything from poor posture to lower back pain. Weak stomach muscles contribute to poor posture during sitting, regular daily activity and weight lifting. Weak abdominals end up straining the lumbar spine or lower back, which is why those with back pain are often prescribed core-strengthening exercises.

If you think you have a muscle imbalance and are unsure of which exercises to do to balance out your muscles, work with a personal trainer and a physical therapist. Performing complementary exercises can prevent muscle imbalance but treating it requires isolated and unilateral exercises that work the weak muscle. Your trainer and therapist may also help you adjust the amount of repetitions in your workout to accommodate your weaker side.

This article was originally posted on PhillyMag.com