Sit-ups and crunches are two of the better known exercises for developing a certain group of muscles in and around the abdominal area. These exercises are simple and effective and, if done properly, can really contribute to a good posture. However, in some cases, doing sit-ups and crunches can cause lower back pain. Here, we examine the causes of this pain and alternative exercises to sit-ups and crunches.

Muscles Affected by Sit-ups and Crunches

Before we look at the causes of lower back pain when doing sit-ups and crunches, it helps to look at what muscles are really affected by sit-ups and crunches.

Sit-ups make use of a group of muscles called the hip flexors. These are muscles connect the thigh bones and lumbar spine or lower back. On the other hand, crunches work on the rectus abdominis, a group of muscles known popularly as the "six pack" because of their appearance. These are found in front of the abdomen.

The Causes of Lower Back Pain during Sit-Ups and Crunches

There are many possible causes of lower back pains when doing sit-ups and crunches.
Some of these are very simple but some probably requires expert opinion.

• Inadequate or no preparation before the exercise. As before any workout you should first do some simple stretching.

• A bad back in the first place. If you have a bad back, sit-ups and crunches are likely to worsen it. This has something to do with a group of muscles which pull on the pelvis and apply pressure on some nerves, causing the bad back pain. In any case, if you have this condition, consult a doctor before doing sit-ups or crunches.

• Overdoing the workout. Too many sit-ups overwork the hip flexor muscles, causing them to tighten up and pull on the lumbar spine to which they are attached. This generates the familiar lumbar pain.

• Incorrect procedure. You are simply not doing it right. For example, you may be pushing your spine into the ground, causing pressure on its posterior.

How to Do Sit-ups and Crunches Correctly

Here is how to do sit-ups crunches correctly:

• Draw in your stomach muscles as you inhale. Take a deep breath and draw your stomach muscles to your spine. You should be able to hold your breath and this position of your muscle for a while.

• Use your stomach muscles during the crunch. Draw in your stomach muscles before you sit up or raise your shoulders off the floor to bring yourself into a crunch. While still holding your abdominal muscles in, use them to lower your shoulders back to the floor.

Additional Exercises for Developing Your Six Pack

There are alternative exercises that can be used to develop your six pack. These have the additional plus factor that they allow you to avoid lower back pain. Here we mention only two of these:

• The front plank. You start this in the prone position, elbows to your sides and hands flat on the floor. Contracting your abdominal muscles you stiffen your torso while stiffening also your legs. Without letting your body sag you raise yourself. Then you lower yourself again with a stiff torso and legs.

• The side plank. In the starting position for this exercise, you lie on one side, legs stretched out, one on top of the other, one arm lying on the upper side of the body and the other supporting your torso such that the forearm rests on the floor. In the upward phase, you inhale, contract your six pack muscles to stiffen your torso and then raise your body. The body must not bend at the hips during this phase. Then you reverse the movement while maintaining the same stiffness.