Short answers to Frequently Asked Questions about the ABTEST is listed below.  

For more insightful explanation, you may choose to review Dr. Barry Brown's 5-page report, with several images here.  Barry has drafted a position paper following many years of research, which can be viewed here:  The Role of the Rectus Abdominis in Predicting and Preventing Low Back Pain


1. What is CORE strength and what muscles are involved?

Answer - CORE strength is difficult to define since there are many claims as to the muscles involved and how they function. According to biomechanists, the CORE is several groups of muscles acting as a stabilizing base that allows either the upper or lower torso to generate extreme forces during lifting or propulsive movements.  The CORE muscles include not only those in your abdominals and back, but also muscles in the hip or pelvic area and upper thighs. Many of your CORE muscles can't be seen because they're buried underneath other muscles. Strong CORE muscles keep your back healthy. They hold your body upright, improve your balance, and form the foundation that allows you to exert maximum effort with your arms and legs. If the CORE muscles are weak, your body doesn't work as effectively, and other muscles have to pick up the slack. This can result in injuries such as a twisted knee, a pulled shoulder, or your classic "bad back.

2. How do we measure CORE strength?

Answer - Because the weakest link in the chain of CORE muscles is typically the abdominals, and specifically the rectus abdominis, ABTEST was designed to measure, quantify, and classify the strength of this critical abdominal muscle. To our knowledge, ABFIT Products is the first to develop a Fatigue Index as a measure of Abdominal Endurance. Both of these parameters are considered crucial components to predict performance and risk of low back injury. Typical tests of abdominal strength that have been around for years do not truly measure strength, but only endurance. The classic bent-knee sit-up with feet held tightly together has been the test of choice when evaluating the rectus abdominis and other contributing musculature (see reference, AAHPERD, 1980). There are two inherent problems with the bent-knee sit-up. First, feet or ankles are supported during this test even though research has shown hip flexor muscles contribute significantly (see reference, Gutin & Lipetz, 1971). Second, the number of sit-ups performed in 60 seconds is a test of endurance since strength is defined as the single maximum effort by a muscle group (see reference, Howley & Franks, 1986). As ABTEST was developed, we conducted studies comparing the results of timed sit-ups to the force recorded on ABTEST.  We found little relationship between the two tests, indicating that the number of timed sit-ups does not measure abdominal strength.

3. How did we come up with the angles, foot and hip position, and pushing point for the cushioned arm for ABTEST?

Answer - Approximately 2 years of research over many successive trials helped us arrive at the specific positioning of the current ABTEST system.   Safety was a critical factor, as was a clear objective for ABTEST to discriminate a range of effort so that everyone would not be classified in the same category. All testing is performed with ankles and feet unsupported and resting on an adjustable platform to maintain the hip and knee angle, and isolate measurement of the rectus abdominis musculature.  ABTEST evolved through five iterations of mechanical and mechanical-electronic systems over a period of four years until we arrived at the basic system.  Further refinements included live graphical display and upgraded software, along with refinements to adjust the unit more precisely.

4. What actually does ABTEST measure and NOT measure or take into account?

Answer - ABTEST measures the isometric strength of the Rectus Abdominis with assistance from the Internal and External Obliques Abdominis and a minimal contribution form the Transversus Abdominis. The ABTEST Strength Index (ASI) is a scaled score from 0 – 100 that displays the values on a scale that is easy to interpret and explain. It is not an absolute but an algorithmic representation of absolute strength. There are five categories displayed on each scale as follows:

a) Needs Immediate Attention (Dark Red) 
b) Needs Improvement (Red)
c) Acceptable (Yellow)
d) Above Average (Light Green)
e) Excellent (Dark Green)

These are description terms only and do not represent a medical interpretation of the risk for low back pain. There are many other factors that contribute to low back pain including a series of muscles located on the lower pelvic floor and muscle located on the back of the spine that include the multifidus and erector spinae (among several others). Structural abnormities within the facets and actual pinching of the nerves as they exist through the intervertebral foramen may also be the etiology of pain. Deformities of the spinal column, itself and congenital factors from birth or through environmental influences may express themselves as a pain response. Acute injury or blow will certainly activate the pain response. It is believed and expressed in many kinesiology, biomechanical, orthopedic and several texts and research articles, that weak abdominal musculature is accountable for 50% of the low back pain and injury experienced by Americans. It is recommended that individuals not be tested if there is suspicion of a physical deformity, acute injury or any sensation of sharp pain when performing a static crunch.

5. What does the graph observed during the actual test mean?

Answer - The graph seen during testing reflects the actual force exerted by the person being tested in real time.  Precision electro-mechanical sensors take multiple measurements every fraction of a second, which are averaged and reported on the graphical display every 250ms (1/4 second).  The numbers on the left hand side (y-axis) are calibrated in pounds. The numbers on the bottom (x-axis) indicates elapsed time in seconds.  The elapsed time is also displayed digitally in a separate box on the top left had corner.  As a person exerts his/her maximum effort, the graph will typically decline in a gradual manner over a 10 second time period.  This decline is presented as Fatigue Index, which is the percentage drop in force over the assessment period.  Propietary ABFIT filtering omits spikes, and narrows the time window of analysis in determining the Max Effort, and Fatigue Index.     

6) How does this force reading correlate with CORE strength?

Answer - It is considered that the abdominal muscle group directly measured by the ABTEST represents the bulk of the CORE musculature, and thus represents a very strong indication of ones' overall CORE strength.  Isolating and measuring every muscle group comprising the CORE presents a very complicated and time consuming challenge.  At present, most research data suggests the abdominal musculature measured using the ABTEST remains the single most important group for looking at the potential for low back pain.   This is also the opinion of many biomechanists, exercise scientists and kinesiologists.  Also, according to professional opinion (justified by the results of our research recently published research in National Strength and Conditional Journal and earlier studies) it is a major predictor of performance. 

7) What should I do with my result?

Answer - After you review your Personal Assessment Report carefully, determine if your ASI and Fatigue Index sCORE meets your expectations based on your current level of functional fitness, athletic activity or occupational requirements.  If your ASI places you in one of the two red color coded categories, you may wish to schedule an appointment with your physician for further diagnostics. If there is no medical/structural explanation for your low sCORE, or a medical condition which would prevent or limit starting a fitness training program, you may wish to embark on a carefully planned CORE exercise program. There are many programs that do not have a scientific basis underlying the progression or even specific exercises. Make sure that you check with your physician, qualified therapist, and certified trainer. ABFIT has developed a scientifically validated CORE Training program with progressions from beginner to advanced, that meets the most recent ACSM guidelines.  One of our Certified Intervention Trainers (CIT) may be available in your area, or contact us for additional materials to get started.