Strong muscles, particularly abs, glutes and hamstrings, take the strain off your back during everyday activities, but these very exercises can also strain your back. What's a gal to do? For one thing, you can make sure you know exactly how to perform certain exercises to avoid injury, which exercises you can modify for a bad back and which ones you should eliminate altogether.
Some exercises can be totally eliminated from your repertoire. Chances are somewhere along the line someone told you that lying on your back and doing straight leg raises works your "lower abs" and flattens your belly. First, straight leg raises can kill your lower back, even if you support them with your hands or a foam roller. Second, there is no such thing as lower abs, since the rectus abdominis is one long muscle that runs down your middle. Straight leg lifts really work your hip flexors. While it's important to work these muscles as a balance to your glutes and hamstrings, you can do this muscles without straining your back. Perform hanging leg lifts with bent knees, either with arm straps or in a captain's chair, or crunches on an inclined bench.
Some exercises shouldn't strain your back, but can if you don't maintain proper form. One of these is straight-leg deadlifts, in which you work your hamstrings and glutes by lifting a barbell or dumbbells from the floor. Done properly they shouldn't damage a healthy back; done wrong they could ruin you. Make sure you start with the weight or weights above your feet, not on the ground. You should also keep your back straight, flexing at your hips and making sure to squeeze your glutes as you come up. It's also important to build up gradually, starting with a very low weight until you are sure you know what you're doing. Of course, if you already have back problems, this is one to avoid. Do leg presses or ball squats instead.
Leg curls on a machine are basic hamstring strengtheners. The safest machines have you doing your curls from a seated position, but some older models have you lying face down -- not ideal for those with back problems. Even with a healthy back there's always the chance for doing it wrong. You may want to opt for another hamstring exercise if the prone leg-curl machine is all your gym has, especially if you're just starting out. Lunges and leg presses are a good alternative.
Any number of safe exercises can strain a weak back, but often you can modify them rather than cut them out of your routine altogether. With bench exercises, such as presses or flys, bend your knees and place your feet on the end of the bench or anything that's the same height. Elevate your feet so your knees are bent at 90 degrees when doing crunches, or do your ab work on a stability ball. Do squats with your back supported against a wall or stability ball.
- ExRx.net: Fat Loss & Weight Training-Lower Abdominal Myth
- ExRx.net: Hanging Leg Raise
- ExRx.net: Dangerous Exercises: Straight Leg Deadlift
- Personal Fitness Training: Theory & Practice; Mary Yoke, MS
- Polka Dot Images/Polka Dot/Getty Images