Back pain can often be prevented/improved by having a strong back and abs, true. However a "6-pack" is a function of low body fat for the most part. Crunches(es

Back pain can often be prevented/improved by having a strong back and abs, true. However a "6-pack" is a function of low body fat for the most part. Crunches(especially unweighted) are a terrible way to make your abs stronger. Good ways to make your back and abs stronger include squats, deadlifts and progressively loaded ab work.