By Ms. Minnie L Jones (IMCOM)January 21, 2010
Almost everyone has experienced some lower back pain, and according to the National Institute of Neurological Disorders and Stroke, low back pain is the second most common neurological ailment in the United States.
Back in 2006, a joint team of physical therapists at the Army Medical Department Center and School on Fort Sam Houston, Texas, in partnership with the University of Florida began a study aimed at the prevention of low back pain and determining whether a core-strengthening exercise program during training might decrease low back injuries.
Since the core-strengthening exercise program did not include traditional sit-ups, they also wanted to determine any impact of the core-strengthening program on Army Physical Fitness Test scores.
The study looked at 3,916 Soldiers in Advanced Individual Training, with half performing a traditional exercise program and the other half performing core-stabilization exercises.
Abdominal sit-ups vs. core-stabilization exercises
Over the years, several studies show that strong core muscles make it easier to do most physical activities. The deeper the muscle is located, the greater the ability it will have for creating and maintaining a healthy spine, and by large, muscular skeletal health.
Several abdominal muscles affect the trunk's posture and ability to function properly: Rectus abdominis (the six-pack muscle), Transversus Abdominus, Internal/External Oblique, and Multifidus muscles. The deeper stomach muscles (i.e., Transversus Abdominus, Multifidus, and Internal/External oblique muscles), also known as the "core" muscles, are the foundation for posture, balance and coordinated movement.
Training these muscles will correct postural imbalances, and allow individuals to perform their chosen sport or activity better without injury.
Several studies have indicated that performing just sit-ups is ineffective because they tend to only strengthen the abdominal muscles closer to the skin (e.g., Rectus Abdominis). Therefore, they do not improve core-muscle strength, in addition, performing traditional sit-ups results in increased loading in the low back that may result in an increased risk of injury and low back pain.
"Sit-ups just train one component of the core, which is the least important component," said Air Force Maj. John Childs, co-principal investigator for the study and associate professor and director of research in the U.S. Army-Baylor University Doctoral Program in Physical Therapy at the Army Medical Department Center and School.
Exercising the key core muscles is important because they surround the body's center of gravity and can improve posture, balance and stability.
"There are many muscles that surround the trunk; however, when you just do sit-ups or crunches; they tend to only work the Rectus abdominis muscles. Having strong deep abdominal muscles is vital for supporting the lower back and preventing lower back pain," said Lt. Col. Deydre Teyhen, study investigator and associate professor in the U.S. Army-Baylor University Doctoral Program in Physical Therapy.
Interpretation of the data so far
One of the concerns that researchers had at the start of the study was that integrating core-stabilizing exercises into AIT could have a negative impact on an individual's APFT scores. However, the results of the study have shown that scores actually slightly increased for Soldiers who completed the core-stabilization exercises.
"Our results showed that core-stabilization exercises, if anything, decrease the risk that a Soldier will fail the sit-up component of the APFT," Childs said. In fact, passing rates among Soldiers who completed core-stabilization exercises improved, 5.6 percent compared to only 3.9 percent among Soldiers who performed traditional sit-ups."
To help translate this finding, in a company of 400 Soldiers, approximately 34 Soldiers fail the sit-up event of the APFT. After 12 weeks of performing core-stabilization exercise, an additional seven out of the 34 Soldiers will pass the sit-up event, who otherwise would have failed, had they only completed traditional sit-ups.
"Although this number seems small, it translates into hundreds of Soldiers each year when you consider the number of Soldiers who compete in physical training every year," Childs concluded.
"The results of this early study demonstrated that training and strengthening of core muscles does not pose any risk of increasing failure rates on the APFT. Rather, pass rates were shown to improve," said Teyhen.
Childs said, "The point of the study is not necessarily to change the makeup of the APFT and eliminate the sit-up component. However, if core-stabilization exercise from our final study results is shown to decrease the incidence of back pain, the next logical step would be to ask ourselves whether we are using the best testing standard."