Low Back Pain Patients Respond to Thrust Manipulation Techniques
For some time now, physical therapists have been trying to find better ways to treat patients with low back pain. By better we mean more effective treatment with successful results. And successful refers to getting relief from pain that doesn't come back.

A group of well-known therapists started by developing a clinical prediction rule (CPR). The rule is used to predict which patients are most likely to have a good response to treatment. This group of therapists has developed a clinical prediction rule that has been tested and found to be valid and reliable for treating low back pain using one particular thrust manipulation technique.

Once that was settled, they turned their attention to whether the same clinical prediction rule could be used for other types of manual therapy. Manual therapy refers to a hands-on treatment given by physical therapists to reduce back pain and improve function.

Manual therapy techniques vary but include thrust and nonthrust manipulation of the spinal joints. The difference between thrust and nonthrust manipulation is the speed or velocity of the force directed through the joint.

The theory behind the use of joint manipulation is changing. For a long time, it was believed that the manipulation changed the alignment of the spine and spinal joints. Once the joint was balanced with everything lined up nicely, movement is restored and stiffness reduced. Therapists were very careful to apply just the right amount of force in just the right direction to achieve the desired results.

But scientists have shed some new light on how and why manipulation might work. And it may have more to do with the effects on mechanoreceptors and motor neuron excitability than on spinal alignment. Mechanoreceptors are tiny antenna in the joint that detect change in motion. Once the motor nerves have been charged up (excited) by injury or trauma, they don't calm down on their own. That's what motor neuron excitability refers to.

If manual therapy can alter mechanoreceptor responses, then maybe any technique used (thrust or nonthrust) will have the same positive effects. Or maybe there are subgroups of patients with low back pain who would respond to one technique better than another. To find out, these therapists treated 112 low back pain patients with one of three manual therapy techniques.

Each patient received two manual therapy treatment sessions with his or her assigned technique followed by three exercise sessions. Exercises prescribed were the same for everyone. All patients met the five criteria for a positive clinical prediction rule. That means they had a high probability of getting relief of back pain with a thrust manipulation manual therapy technique.

In addition to having low back pain with or without leg pain (sciatica) painful symptoms had to be present for less than 16 days to meet the clinical prediction rule (CPR). Other criteria in the CPR included: the pain did not go down past the knee, at least one spinal segment was hypomobile (stuck or lacking full motion), and at least one hip had 35-degrees (or more) of internal (inward) rotation range of motion.

A specific test for fear-avoidance behaviors was also administered. Patients with high scores on this test are fearful of movement and tend to avoid doing anything they think might cause pain. Patients with low scores on the test were more likely to benefit from manual therapy. When a patient met four of these five criteria for the clinical prediction rule, then they could be (randomly) assigned to the 1) the supine thrust manipulation group, 2) sidelying thrust manipulation group, or 3) nonthrust manipulation technique group.

The authors described each technique and provided photos of a therapist performing each one. The supine thrust manipulation was the treatment used when they first developed and tested the clinical prediction rule. The other two treatment techniques were added in this study for comparison. Spinal motion and strengthening the core (trunk) muscles formed the basic exercise program. These exercises were also used during the original studies to develop the prediction rule.

After completing the treatment and exercise program, patients were rechecked at one week, four weeks, and after six months. Patients were asked about any side effects from the treatment such as muscle spasm, fatigue, stiffness, or pain/discomfort. One in four patients experienced at least one side effect but this was not linked with the type of manual therapy treatment they received. Most of the time, when a problem occurred, it was worsening pain with increased stiffness within the first few hours of treatment. These symptoms went away gradually over the next 48 hours.

As far as which treatment(s) were most effective, they found that the two thrust manipulations performed in different positions (on the back, on the side) were equally beneficial. Patients in the non-thrust group had significantly less benefit in the first month of follow-up. By the end of six months, there was no difference in pain or function from one group to the other. The results of all test scores favored early treatment with thrust manipulation and supported the clinical prediction rule using the alternate thrust technique (sidelying) as well.

Patients from different geographical areas were included in this study in an attempt to see if the manual therapy treatments would meet the clinical prediction rule somewhere besides where the main researchers were working. In other words, can the clinical prediction rule be used in other settings besides the one it was developed in? Early results suggest yes, the clinical prediction rule can be generalized to other settings but more research is needed to confirm this finding.
Joshua A. Cleland, PT, PhD, et al. Comparison of the Effectiveness of Three Manual Physical Therapy Techniques in a Subgroup of Patients with Low Back Pain Who Satisfy a Clinical Prediction Rule. In Spine. December 1, 2009. Vol. 14. No. 25. Pp. 2720-2729.