Physical Therapists Move Ahead With Research to Prevent Chronic Low Back Pain
New information on the role of psychological factors in chronic low back pain (LBP) is being reported and studied. One of the latest models for managing LBP is called the Fear-Avoidance Model (FAM). The idea is that fear of movement and fear of re-injury result in avoiding movement and eventually lead to loss of function and disability.

Studies show support for this idea. Pain-related fear affects how patients respond to their pain. Pain catastrophizing is a part of the problem. People who catastrophize tend to do three things. They think about their pain and can’t stop thinking about how much it hurts. They blow their pain out of proportion and are afraid that there might be something really serious wrong. And they feel helpless to change their pain, believing that there is nothing they can do to reduce their pain.

In this study, different physical therapy treatment approaches for low back pain were compared. Effectiveness of each method on pain intensity, pain catastrophizing, disability, and fear-avoidance beliefs was examined. Physical therapists use a treatment-based classification (TBC) system to identify which type of treatment should be used with each patient.

Some of the treatment categories used with this model include specific exercise, mobilization or manipulation, spine stabilization, or traction. The treatment-based classification approach is based on previous research done and validated by a well-known physical therapist (Tony Delitto, PT, PhD) from the University of Pittsburgh.

All the patients in the study had acute or subacute LBP defined as back and/or leg pain lasting between one week and six months. Ages ranged from 16 to 60 years old. Patients with chronic pain (lasting more than six months) were excluded from the study. This study focused on working with patients in the acute and sub-acute phase hoping to resolve behavioral issues and avoid chronic pain from developing.

Everyone was assigned to a treatment group based on the treatment-based classification system. They also received instruction in one of two methods to reduce fear-avoidance behavior: graded exercise or graded exposure.

Graded exercise starts by finding out how much exercise each patient can do before their pain stops them. This is referred to as exercising to pain tolerance. Then the patient is enrolled in a program that starts with that level of exercise or activity. The therapist guides the patient in building tolerance by slowly increasing duration, intensity, and frequency of the exercise or activity.

The graded exposure approach starts by looking at which activities patients are fearful of (e.g., lifting, carrying, twisting, bending). Each of those activities is then practiced under the supervision or guidance of the physical therapist. Patients start at a level that feels safe to them. They rate their fear before and after each activity. As their fear goes down, the frequency, intensity, and duration of the activity is increased. Then they are encouraged to start doing the same things at home on their own.

In a previous study, these same authors showed that physical therapy combined with graded exercise was helpful but only for patients with pain-related fear. Then another group published a report about the benefits of using graded exposure for patients with chronic LBP. Research so far has not answered the question of which method to use for patients with pain-related fear. So this study is to compare them both to see which one works better.

Everyone participating in the study filled out a variety of surveys and questionnaires to assess patient preference, satisfaction with treatment, pain intensity, disability, and fear-avoidance behavior. Well-known tools were used such as the Oswestry Disability Index (ODI), the Fear-Avoidance Behavior Questionnaire (FABQ), the Pain Catastrophizing Scale, and the Physical Impairment Scale (PIS).

Outcomes were measured by comparing baseline (before treatment) values with responses four weeks after treatment and again six months after treatment. Were there changes in fear-avoidance beliefs, pain catastrophizing, or physical impairment? Well, first of all, they noticed that everyone in both groups made progress. They had less pain, less fear, and less disability.

It did not appear that graded exercise was any more effective than graded exposure. And neither one of these approaches worked any better than treatment-based classification for patients with fear-avoidance beliefs. The original hypothesis of the study (patients with pain-related fear would get the most help from graded exposure) was not supported by the results. They were not able to replicate the previous study's results showing that graded exposure was more effective than graded exercise in reducing fear-based back pain.

When trying to make sense of the results, the authors suggested that treatment-based classification may be effective enough that no other additional treatment add-ons are needed. Or maybe there are more effective ways to apply graded exercise and graded exposure than were used in this study. Perhaps the timing of treatment with these graded methods is important (i.e., stage of low back pain). Maybe like treatment-based classification, there are subgroups of patients who will respond better to graded exercise or graded exposure.

The authors recommend further studies with larger group sizes to help answer these questions. They also suggest it's possible that pain-related fear isn't the most important factor in explaining why patients progress from acute and subacute to a chronic state of low back pain. Finding risk factors (including psychologic or behavioral factors) remains an important need before specific treatment can be identified that will be effective in preventing chronic low back pain.
Steven Z. George, et al. A Randomized Trial of Behavioral Physical Therapy Interventions for Acute and Sub-acute Low Back Pain. In Pain. November 15, 2008. Vol. 140. No. 1. Pp. 145-157.