There are a lot of good reasons to perform special exercises for the muscles of the lower back beyond just helping to prevent back pain.

Strong erector spinae muscles not only help ensure proper form in multijoint exercises such as squats, they also have an “irradiation effect” on other muscle groups. What this means is that if you strengthen these muscles, you’ll also increase your strength in seemingly unrelated exercises such as the overhead barbell press and even standing dumbbell curls.

The key, however, is to use effective exercises and find ways to make your workouts progressively more challenging. Here are 10 ways to do just that:

1. Perform back extensions, not hyperextensions. One of the primary muscle groups the back extension works is the erector spinae, a set of three parallel muscles: the iliocostalis, longissimus and spinalis. These muscles run the entire length of the spine, starting from the sacrum all the way up to the base of the neck. The functions of these muscles include extending and laterally flexing the vertebral column and helping to maintain optimal posture of the spine during exercise.

One of the most common errors in performing back extensions is lifting the

torso above parallel, causing the spine to go into hyperextension. Lifting the torso above parallel places adverse stress on the L3 to L5 vertebrae and may lead to back pain. One advantage of performing back extensions on a 45-degree angled back extension bench is that it makes you more aware if you are lifting your torso too far into hyperextension. Also, the incline version of this exercise tends to create more traction (and thus decompression) on the spine at the start of the exercise, and this effect can be beneficial for many individuals who suffer from back pain.

2. Use resistance on back extensions. Often back extensions are performed without any resistance for higher reps, which does little to develop strength or muscle mass. Soviet weightlifters were known to perform this exercise with barbells weighing hundreds of pounds placed on the back of their shoulders -- even bodybuilders would use impressive weights in this exercise. The late Reg Park, the first bodybuilder to bench press 500 pounds and who Arnold Schwarzenegger considered his role model when he started pumping iron, would perform 45-degree back extensions with as much as 255 pounds for 10 reps!

3. Vary how you use resistance on back extensions. Supporting a barbell across the shoulders can be uncomfortable, but there are several alternative ways to make these exercises more challenging.

First, you can hold a dumbbell or weight plate across your chest. Another way to make back extensions more difficult is to change the leverage throughout the exercise. Hold a dumbbell, weight plate or medicine ball close to your chest, move to the top position of the exercise in the normal fashion, then extend the dumbbell or other implement in front of you. Lower slowly with arms outstretched, parallel to the torso. The resistance is increased when the arms are extended because the lever arm is longer.

You can also perform back extension exercises with a barbell placed on the floor. Position a barbell on the floor with the bar directly over your shoulders. Grasp the bar with extended arms, and then straighten your torso until it is parallel to the floor. The height of the Olympic plates limits the range of motion of the exercise, but you can increase the range of motion by using a wider grip or loading the bar with smaller-diameter plates.

4. Add good mornings to your exercise toolbox. The good morning has always been a key exercise by weightlifters and other Iron Game athletes to

strengthen the lower back. In fact, 1959 Mr. Universe Bruce Randall could perform this exercise with 685 pounds (knee flexed, back parallel to the floor). In recent years, however, the Romanian deadlift has become a more popular exercise for these muscles.

As opposed to the conventional deadlift, the good morning begins from a position of advantageous leverage and begins with an eccentric contraction. The key to safely performing this exercise is to pivot from the hip – rounding your lower back is asking for trouble -- and keep your knees slightly bent. However, because the exercise places high levels of posterior shearing stress on the spine, it should not be performed by anyone who has disk issues or who experiences pain when doing this exercise.

5. Perform reverse hypers correctly. Powerlifting coach Louie Simmons can be credited for making the reverse hyper (or reverse back extension) the number one assistance exercise for the deadlift, and its popularity has spread to the field of strength and conditioning for many other types of athletes.

The exercise is especially valuable for those athletes with disk problems because the compression forces on the disks are low. The reverse hyper is also the exercise of choice for those with an excessive anterior tilt of the pelvis and chronic tightness in the lower back. This is because the exercise stretches the muscles of the lower back – especially those benches that have the chest pad tilted downward -- and works them while maintaining a neutral spine. However, when performing the exercise, especially those who have a history of back problems, the legs should stop short of parallel. Going to parallel or higher causes the spine to hyperextend, placing excessive stress on the L3 to L5 vertebrae.

Although both back extensions and reverse hypers work the spinae erector muscles, one theory is that conventional back extensions target the mid-part of the lumbar spine (above L3) and reverse hypers target the lower part of the lumbar spine (below L3). As such, it’s important to perform both of these exercises to develop these important muscles to their fullest.

6. Consider unique variations of conventional back extensions. If an individual has one leg shorter than the other their spine will often rotate during the deadlift, and this may cause back pain. Performing the back extension exercise without the footplate may be more comfortable than both deadlifts and conventional back extension exercises because it reduces the

amount of rotation of the pelvis.

7. Think twice about seated back extension machines. Alf Nachemson of Sweden published research in 1975 showing that leaning forward just 15 degrees from a seated position can nearly double the compressive forces on the L2-3 vertebrae. Further, compared to the reverse hyper, a seated back extension machine does not provide a good stretch on the erector spinae muscles, which is a benefit that those with back problems may need. The bottom line is that you should certainly avoid seated back extension machines if you have a history of back problems.

8. Perform back extensions from different angles. You encounter the highest level of resistance during a back extension when your torso is parallel to the floor. However, you can change the resistance curve of the exercise by performing the exercise on an incline back extension bench. With the incline version you will feel more resistance at the start of the movement, and with the flat version you will feel the most resistance at the finish. Varying the angle that you perform back extensions more completely overloads all areas of the strength curve of the erector spinae muscles.

9. Use a variety of repetition protocols. The erector spinae consists of both high-threshold motor units (fast-twitch muscle) and low-threshold motor units (slow-twitch muscle). To adequately work both types of motor units, you need to perform workouts that use low reps with heavy weights and also workouts that use high reps with relatively lighter weights.

10. Allow adequate recovery between workouts. Exercises that work the spinae erector muscles, especially deadlifts, take much longer to recover from than other muscle groups. In fact, many powerlifters often train the deadlift heavy only once every 7-10 days to allow for complete recovery of these muscles. In contrast, because the Hex bar is performed with a more upright posture and thus placing less stress the lower back muscles, athletes can often perform this exercise heavy more frequently, such as once every five days.

The lower back muscles may not be the most enjoyable muscles to train, but if you put some effort into working them and train them smart, you’ll find the results are definitely worth it.