Meeting the Mark: Essential Requirements for Meaningful Testing of Lumbar Functions Part 1

The assessment of lumbar functions is critical in evaluating the health and performance of the lower back. Specific requirements must be met to ensure that testing is comprehensive and reliable. In this blog post, Chapter 4 of “Safe, Specific Testing and Rehabilitative Exercise for the Muscles,” Part 1 will explore the essential requirements for conducting meaningful testing of lumbar functions. By understanding and meeting these requirements, healthcare professionals can ensure accurate assessments and provide optimal care for individuals with lumbar issues.

A. Isolation of the Lumbar Muscles:

When testing to see the strength of the lumbar muscles, you have to first provide without total isolation of those muscles. If forces are involved from the buttocks and hamstring muscles, then they cannot be involved in tests to measure the strength of the muscles that extend to the lumbar. Now, forces from the torso-rotation muscles will be involved when performing the tests on measuring trunk-rotational strength. To get accurate test results, tested muscles must be in total isolation. This also means to test the strength of the lumbar muscles; you have to anchor the pelvis.

B. Anchoring the Pelvis:

Though one of the most challenging requirements, anchoring the pelvis is vital to ensuring accurate testing of the lumbar area. When testing the lumbar extension, if the pelvis is free to move or free to move slightly, then the forces produced by the buttock muscles and the thigh muscles will be confused with the results needed. Which are the forces produced by the lumbar muscles. This can cause errors in the development. When testing the lumbar strength, the direction of extension when testing the pelvis naturally tends to tilt forward while the bottom of the pelvis moves forward. And when testing during the torso-rotational strength, the pelvis managed to twist. Having both movements will create errors in the results.

The pelvis must be anchored to the front to prevent the movements, but there’s one problem. The pelvis can’t go to the front, the legs are in the way, and stabilizing the force against the front of the pelvis cannot be done. But your femur is joined by the pelvis. This means that to get such movement, the pelvis must move to the femur; even if you cannot block the movement, you can, however, block the movement of the femur.

C. Coaxial Alignment of the Effective Axis of the Lumbar:

Measuring the extension strength of the lumbar muscles involved the movement around these five joints. They are the joints between L5 and the sacrum, and then it is each of the joints below the other four vertebrae. With that being said, because of the constant movement of each of the five-axis points, the length of the lumbar spine also changes. But there is a solution to this issue. The solution was that the seating and restraint structures of the lumbar testing machine could properly accommodate anybody from a height of under 5 ft to more than 7 ft. This means the machine can detect the moment-arm of force being produced without harming the results.

D. Counterweight of the Moving Components of the Testing Machine

The testing machine of all the moving parts must be counterweighted. Counterweighted means: counterbalance; all the force needs to be equivalent in weight. If not, then there will be random levels that will be detected, which will then make the results worthless.

E. Determination of the Center-Line of the Torso Mass

The torso, head, and arms mass must also be counterweighted. But before anything, you have to determine the center-line of the mass. Since there are different body types along with shapes, the center-line of the mass will vary from subject to subject. Unless you have one single variation, then it’s impossible to determine it. For instance: when dealing with someone who happens to be tall, obese, and has bad lower back issues, it’s impossible for the subject to move, which makes the results dismissable. Due to it being impossible to test the subject. Now if the subject is weak, it can produce torque– a force that produces or tends to produce rotation or torsion. But it still needs to be addressed as the need for accuracy and reasons for safety.


Conducting meaningful testing of lumbar functions requires adherence to specific requirements. Isolation of the lumbar muscles is crucial to accurately measure their strength while anchoring the pelvis helps prevent unwanted movements and ensures accurate results. Coaxial alignment of the effective axis of the lumbar is necessary to accommodate variations in spinal length and ensure accurate force measurement. Counterweighting the moving components of the testing machine and determining the center line of the torso mass is essential for reliable results.

These requirements contribute to the accuracy, reliability, and safety of lumbar function testing. In the next blog post, part 2 of Chapter 4 from the book “Safe, Specific Testing and Rehabilitative Exercise for the Muscles” will explore specific testing methods and considerations for meaningful assessment of lumbar functions. Stay tuned for more valuable information on this important topic.



  1. Jones, A., Pollack, M., Graves, J., Fulton, M., Jones, W., MacMillan, M., Baldwin, D. D., & Cirulli, J. (1988). Safe, specific testing and rehabilitative exercise for the muscles of the lumbar spine. Sequoia Communications.