Trunk strength testing in patient evaluation and treatment.

A wide variety of trunk strength testing devices has been developed, the goal being to quantify back strength, patient effort, and spinal function or dysfunction. Although the idea of applying quantitative values to spine function is appealing, controversy exists regarding the reliability and validity of these testing systems. In this issue, two experienced investigators give their opinions as to the values and pitfalls of lumbar trunk strength testing, and provide insight into the most appropriate applications of these often costly systems.