Mechanical low back pain continues to confound health care professionals and researchers alike. Efforts to understand causes, effects, and find the best treatment are ongoing. In this study from Sweden, physical therapists compare the usefulness of two specific tests of disability: fingertip-to-floor and straight leg raise tests.
Both tests have been shown to measure a specific physical disability. But is either test a better measure of treatment outcomes? Can physical therapists use these tests to predict who will get better and by how much? That is a broad question when dealing with all low back pain patients. So they narrowed their focus to a subgroup of just patients with radicular pain (back pain with pain down the leg).
Each of the 65 patients in the study was diagnosed with acute or subacute low back pain (meaning their painful symptoms were fairly new: less than 13 weeks). Disability was measured using a well-known self-reported survey (the Roland Morris Disability Questionnaire or RMDQ).
The RMDQ assesses daily activities on a scale from no disability to severe disability. Everyone filled out the questionnaire at the beginning (baseline), after one month, and after one-year. Each patient also had a positive slump test to verify the presence of radicular pain. And a measure of fingers-to-floor was taken for each one.
As the name suggests, the fingers-to-floor test is done in the standing position. The person bends as far forward as possible reaching toward the floor with the fingers. The number of inches or centimeters from the tip of the index finger to the floor is the test result.
The slump test involves assuming a “slumped” position: sitting with spine flexed forward (bent over) and head and neck forward flexed (chin to chest). Once in this position, the therapist directs the patient to lift and straighten the leg with ankle dorsiflexion (toes pulled toward face). Reproducing pain down the leg is a positive slump test. It is an indication that the sciatic nerve is being stretched or compressed (though it does not reveal the cause of the nerve tension).
In the meantime, everyone was treated by one physical therapist for an average of six sessions. Some patients had as few visits as two while others had as many as 16. The therapist described the techniques used as including the McKenzie method (specific movements and exercises), manual (hands on) therapy, and stabilizing (core training) exercises.
There were two major findings from this study. First, change in fingers-to-floor was associated with improvements in daily function (as measured by the Roland Morris Disability Questionnaire). Second, patients who had improvements in the fingers-to-floor measurement in the first 30-days of treatment had the best long-term results.
The authors of this study direct their final thoughts to physical therapists evaluating and treating patients with acute or subacute mechanical low back pain. They suggest using the slump test to find the subgroup of patients with radicular pain. They suggest using the fingers-to-floor as a measure of change and a predictor of who will improve with treatment. The fingers-to-floor is a more valid test to predict change in disability over time than the straight leg raise test.