One of the things I want to start adding to my blog are posts commenting on recent or past studies either bashing them or singing their praises.  With all the books, magazines, articles, internet, blogs and other forums there is so much information out there on almost every topic under the sun.  Whats even worse is that for each good piece of information there are over a hundred bad ones.  So for your sake I want to separate the gold from the turds.

In today’s post I just wanted to share an excerpt from Muscles: Testing and Function by Florence Patterson Kendall, P.T. and Elizabeth Kendall McCreary.  Yes, I am a nerd and yes, I read books like this in my leisure.  And yes, I just said “in my leisure”.  The book was published in 1983, hey I was born that year!  Anyways, the section I wanted to share with all my readers is the introduction to the section on trunk muscles.  It gives a great explanation on why you should not be doing many crunching or situp exercises.  I touched on this a few months ago in this post.

Here is some gold from the past:

Proper exercise is an important part of preventative medicine and the public has a right to know which exercises are beneficial and which are harmful, and to know the reasons why.  It is the purpose of this chapter to provide accurate information of a technical nature in a manner that will help make the material useful to many people in the fields of healthcare and physical fitness.

The public is bombarded with fitness programs that include exercises that are supposed to strengthen abdominal muscles.  Many of the exercises are inappropriate or ineffective, and some cause harm.  Attention should be focused on the following concerns:

Subjects with marked weakness of abdominal muscles cannot perform trunk raising in the correct manner of curling the trunk, and, consequently, they do it incorrectly with the low back arching forward, subjecting the abdominal muscles to stretch and strain.

Subjects who do the curled-trunk sit-up correctly (with legs extended or flexed), but do it to excess in frequency and/or duration, may develop excessive flexibility of the back, and shortness of the hip flexors.  These adverse effects may be more pronounced from doing the knee-bent sit-up than from doing the sit-up with legs extended.

In many exercise programs, sit-ups are the only abdominal exercises included.  The programs fail to include proper pelvic tilt exercises that strengthen the muscles most needed to hlep maintain good alignment of the trunk and pelvis in standing.  Furthermore, when pelvic tilt exercises are done, they frequently are done without any action on the jpart of the abdominal muscles.

This is basically saying that most people crunch and/or do sit-ups because that is the only thing that they know how to do.  In most cases this is doing more damage than good, mainly because or hip-flexors are super strong and tight from sitting at a desk all day and a couch all night.  Most people that I see in the gym doing crunches or variations are doing them wrong in the first place.  Even worse is that damn plate loaded “frog” crunch machine that is even further helping to wreck people’s lower backs.  Bravo Hammer Strength Company.

Kendall continues on muscle imbalances (which you may hear me yap about from time to time) and some of the confusion about what your trunk or “core” muscles are:

…muscle imbalance frequently exists between abdominal and hip flexor muscles in trunk-raising forward from a supine position, as in the sit-up.  Hip flexors usually are strong, not infrequently abdominal muscles are weak, and have less endurance than hip flexors.  Whenever there is muscle imbalance there is a tendency for stronger muscles to substitute for weaker ones in movements that ordinarily involve both groups.  Because the hip joint moves through approximately 80 degrees of flexion during the sit-up, irrespective of the position of the trunk or of the lower extremities, it is possible for the hip flexors to perform the trunk-raising when abdominals are weak.

Many people become aware of abdominal muscle weakness because of a painful low back, because being unable to get up easily from a lying position, or simply because they are concerned about their appearance and posture.  The traditional exercises of sit-ups and double-leg-raising have been offered as the panacea for strengthening these muscles.  Unfortunately, they are not the “cure-all” that they are supposed to be.  Much of the confusion has been  caused by failure to distinguish the action of the abdominal muscles from that of the hip flexors during these exercises.  People with strong abdominal muscles can do sit-up or leg-raising exercises without harmful effects; those who have weakness are often affected adversely.  When there is marked weakness, use of these two exercises should be avoided because they can further weaken and strain the abdominal muscles, instead of strengthening them.  There is evolving a better understanding of the uses and abuses of double leg-raising and sit-ups but indiscriminate use of these exercises still persists.

A good personal trainer or physical therapist should be able to locate these imbalances and prescribe proper exercises to correct them.  If they are not constantly assessing your posture and form you may want to reconsider their services.  I have been in this industry long enough to see some pretty bad practices among some so-called professionals to say that all trainers are not created equal.

Don’t forget this was written in the early 80’s so wtf have we been doing since then?!

I can’t stress enough how important it is to stretch your hip flexors and strengthen your posterior hip extensor muscles like your glutes, hams, and lower back if you work a desk job.  This alone should help keep you mobile well throughout your glory years and keep your back pain free.  Seriously.  Focus on posterior chain exercises like back extensions, hip-thrusts, and bridges as well as total body exercises like squats and deadlifts.  I have even read that proper pull ups activate your rectus abdominus or “six pack” muscles more than doing crunches.  Hmmm.

My best advice if you want to see your six pack muscles is to keep your hairy ass out of the fridge.  

Peace, love, and quit doing so many crunches damnit!!


Written by Steve