FAYETTEVILLE, Ark. - Those of you counting crunches at the local gym might want to listen up. A study from University of Arkansas exercise scientists indicates that sit-ups - long endorsed as the standard for assessing abdominal strength - actually measure endurance, not strength. But the UA researchers have developed a device that does what sit-ups cannot do . and nobody has to hold your ankles.

Barry Brown, professor of exercise sciences, has invented a mechano-electronic system that isolates abdominal muscles and measures their strength through the forces they exert. Called the Abdominal Measurement Device, or ABMED, this instrument requires only 3-5 seconds of exertion to record abdominal strength. Through the use of the ABMED, Brown and UA colleague Dean Gorman have more accurately measured abdominal strength and linked it to the incidence or prevention of lower back pain and injuries.

Dean Gorman, professor of exercise science, shows graduate student Ivy Jones how to position herself to use the ABMED.

"There’s been a lot of anecdotal evidence about the connection between abdominal strength and lower back injury but not much hard evidence. That’s part of the reason we conducted these studies," Brown said. "Now that we have an accurate assessment tool to measure strength, we can start looking at correlations."

Brown and Gorman recently presented the results of their research at the IOC Olympic World Congress on Sport Sciences in Athens, Greece. The IOC nominated one of their studies, "Abdominal Strength vs. Endurance and Its Relationship to Low Back Injury Among University Football Athletes," for the prestigious Prince Alexandre de Merode Award.

The study evaluated 41 Division I university football players using two test methods. In the first test, athletes completed 60-second intervals of sit-ups with ankles held - the standard test of abdominal strength recommended for more than 20 years by the American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD).

In the second test, researchers used the ABMED to assess strength. Subjects reclined on a bench designed to support their torsos, hips and knees at specific angles. With arms crossed, the subjects pressed their chests against a mechanical arm as if trying to sit up, exerting increasing force for a 3-5 second period. The ABMED recorded the maximum force, which could then be analyzed as a measure of muscular strength.

According to Brown, the ABMED specifically positions subjects’ torsos so that only the rectus abdominus muscles are used to exert force. By leaving the lower body unsupported, Brown’s device prevents subjects from recruiting their hip and leg muscles into the action - a common problem with sit-ups.

"The 60-second test recommended by AAHPERD allows for too much cheating. A lot of people use their hip flexors or the momentum of the sit-up to aid their abdominal muscles," Gorman said. "This device isolates the abdominals to measure their strength without interference."

Upon completion of the study, Brown and Gorman found no relationship between abdominal strength and endurance and very low correlation between abdominal strength and height or weight. But the researchers did find a correlation when they examined ABMED results in relation to lower back pain. Among the offensive linemen who participated in the study, those who reported prior or recurring back pain registered significantly weaker abdominal strength on the ABMED.

Since offensive linemen often represent the largest players on a team - weighing upwards of 300 pounds - Gorman and Brown speculate that abdominal muscles help them support the weight around their torsos. Linemen with weaker abdominals put significant strain on their lower backs, which could lead to pain or injury.

It’s an effect the researchers have also identified outside of athletics. In subsequent studies using the ABMED, Brown and Gorman have evaluated the correlation between abdominal strength and back pain among factory line workers and employees at local corporations.

"We noticed a significant difference in abdominal strength between those who had incurred back injury and those who had not," Brown said. "Employees who reported injuries showed one-quarter to one-fifth the abdominal strength of those who reported being injury free. From that, we can extrapolate that abdominal strength plays a definite role in injury prevention."

Gender may also play a part in the relationship between muscle strength and injury prevention, the researchers said. In addition to studying football players and workers, Brown and Gorman have used the ABMED to evaluate female athletes.

"It’s possible that abdominal strength is even more critical for women than for men - partly because of the forces their bodies must endure during athletic activity. Women’s bones are more slender in structure and have lower density than men’s, but they must withstand forces 3-5 times that of body weight during jumping or running maneuvers," Brown said. "Because of that, the use of abdominal muscles as a stabilizer may be very important to women’s physical performance and health."

# # #