Drivers Beware:
Lumbar Support Can Be Harmful To Your Health!


The Problems with Traditional Abdominal Exercises

Popular abdominal exercises such as crunches, sit-ups, and abdominal machines distort your posture by overdeveloping the upper abdominal region (the upper rectus abdominis muscle), while depressing the chest and rib cage, and rounding the upper back and shoulders.

   The end result: These exercises reinforce a slumped posture without correcting a protruding lower abdomen.

Figure A

Figure B

  By rotating Figure A ninety degrees clockwise, this classic illustration from 1899 shows how the postural depression resulting from crunches, sit-ups, and abdominal machines (Figure B) is very similar to the postural depression in common sitting postures (Figure A).   (From Bradford, E.H., and Stone, J.S.: The seating of school children. Transactions of the American Orthopaedic Association, 12:170-183, 1899.)

  In addition, expending continuous effort throughout the day to "hold the stomach in" mainly constricts the upper abdominal region, just below the ribs. This habitual constriction further weakens the lower abdominal region instead of flattening it, along with restricting proper diaphragmatic breathing.

  A tightening and flattening of the lower abdominal region occurs naturally and effortlessly when upright due to the activation of postural reflexes.

  The keys to activating these postural reflexes, all reinforced with the YogaBack, are as follows:


Anderson, T. McC.: Human Kinetics and Analysing Body Movements. London, Heinemann, 1951.

De Troyer, A.: Mechanical role of the abdominal muscles in relation to posture. Respiration Physiology, 53:341-353, 1983.

Drew, L.C.: Individual Gymnastics, 5th ed. Philadelphia, Lea and Febiger, 1945.

Floyd, W.F., and Silver, P.H.S.: Electromyographic study of patterns of activity of the anterior abdominal wall muscles in man. Journal of Anatomy, 84:132-145, 1950.

Frost, L.H.: Individual structural differences in the orthopedic examination. Journal of Health and Physical Education, 9:90-93,122, 1938.

Lipetz, S., and Gutin, B.: An electromyographic study of four abdominal exercises. Medicine and Science in Sports, 2:35-38, 1970.

Sarti, M.A., Monfort, M., Fuster, M.A., and Villaplana, L.A.: Muscle activity in upper and lower rectus abdominis during abdominal exercises. Archives of Physical Medicine and Rehabilitation, 77:1293-1297, 1996.

Wiles, P.: Postural deformities of the anteroposterior curves of the spine. The Lancet, 1:911-919, April 17, 1937.

Zacharkow, D.: Posture: Sitting, Standing, Chair Design and Exercise. Springfield, Thomas, 1988.

All site contents are Copyright 2002-2018
The YogaBack Company
P.O Box 9113, Rochester, MN 55903   
1-800-SITTING (1-800-748-8464)

[The YogaBack Company] [The YogaBack for Driving] [ZACKBACK Chair] [Posture Textbook]  
ORDER FORMS:   [YogaBack for Driving Order Form] [Posture Text Order Form]