Forget crunches — my physical therapist gave me this exercise to work my abs without aggravating my lower back pain

(Image credit: Shutterstock) I suffer from sciatica, so I have to be mindful when it comes to ab exercises like crunches and sit-ups, which typically put a lot of stress on the lower back. In the run-up to my last marathon, I asked my physical therapist for an ab exercise that would build core strength and stability without stressing my back — read on to find out what he said next.As a reminder, what works for me might not work for you or your body. If you’re a complete beginner, pregnant or postpartum, or recovering from an injury or surgery, it’s always best to seek personalized advice from a qualified professional.3 spine-safe exercises for working your core When it comes to a spine-safe way to work your core, the main exercise my therapist recommended is the bird-dog. Read on to find out how to do a bird dog with perfect form, its benefits, plus two other back-friendly exercises to add to your routine.1. Bird dog (Image credit: Shutterstock)Unlike crunches, which force your back to bend as you lift your head, neck, and shoulders off the mat, bird dog teaches your abdominal muscles to hold your spine in place while your limbs move. This helps build the functional fitness you need for everyday life, as well as during sports like running.As you perform the bird dog, you’ll be working the deep stabilizer muscles that run along the spine and glutes, rather than the outer six-pack muscles. The deep core works as the body’s corset and helps protect your spine from injury.Here’s how to do the bird dog exercise with good form:Start on all fours, with your hands stacked underneath your shoulders and your knees under your hips. Keep your head and spine in a neutral position, so your back and neck are straight.Engage your core, thinking about zipping your abs up and in, and squeezing your belly button into your spine.Slowly, with complete control, extend your right arm straight out in front of you, while also extending your left leg straight back. They should form a straight line with your torso.Pause here for a few seconds, making sure your hips don’t rotate. Imagine there’s a light on each hip — both should be shining down on your mat.Return slowly to your starting position and repeat on the opposite side.Keep alternating until you’ve completed 8-10 reps per side.2. Dead bug (Image credit: Shutterstock)Another safe exercise to try if you suffer from lower back pain is the dead bug. Again, unlike a crunch or a plank, this exercise targets those all-important deep abdominal muscles while keeping your lower back supported.Get instant access to breaking news, the hottest reviews, great deals and helpful tips.A huge benefit of the dead bug is that it’s performed lying flat on your back, meaning there is no compressive load on your spinal discs, as you’re not having to fight gravity to hold the pose. This allows you to build core strength and train yourself to maintain a neutral spine without triggering any pain in your lower back.Here’s how to do a dead bug:Lie on your back and raise your arms and legs to a tabletop position: this means your arms are pointing straight up to the ceiling, and your knees are bent at 90 degrees, with your knees in line with your hips.From here, press your lower back into the floor. Engage your core, squeezing your belly button into your spine.Slowly lower your right arm overhead, keeping your arm straight, and at the same time, extend your left leg. Only lower both limbs as low as you can without letting your lower back peel off the floor.Bring both back to your start position and repeat on the opposite side.Keep alternating until you’ve completed 8-10 reps per side.If this is too much for you, start with bent-knee taps. Instead of straightening your leg, keep your knee bent and tap one heel down to the floor, then bring it back to your starting position and repeat on the other side.3. Glute bridge (Image credit: Shutterstock)For the final move in this spine-safe series, the glute bridge is a great exercise for strengthening the glutes, hamstrings, and lower back stabilizers without putting pressure on your spine.The core isn’t just the muscles that sit on the front of your body — it also includes the erector spinae (the muscles running along your spine) and the multifidus (the deep stabilizing muscles in the lower back). This exercise works these muscles, as well as waking up sleepy glutes. If your glutes don’t fire properly, your lower back muscles can overcompensate, leading to tight back muscles.Here’s how to do it:Lie on your back with your knees bent and your feet flat on the floor, hip-width apart. Your heels should be close enough to your glutes that you can just about touch them with your fingertips.Engage your deep abdominal muscles, slightly tilting your pelvis back so your lower back is flat against the floor.Drive through your heels to lift your hips towards the ceiling. Stop when your body forms a straight line from your shoulders to your knees, making sure you don’t over-arch your lower back.Squeeze your glutes at the top for a couple of secondsSlowly lower down to your starting position.Follow Tom's Guide fitness on Instagram for more workouts, routines, tips, and tricks. Follow Tom's Guide on Google News and add us as a preferred source to get our up-to-date news, analysis, and reviews in your feeds. Alternatively, you can read our content on the Tom's Guide app available now for iOS and Android. Subscribe to Tom's Guide on YouTube and follow us on TikTok. 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