RCT of Motor Imagery of Extension for LBP vs. Exercise

Overview

Low back pain (LBP) is the most common musculoskeletal condition treated in physical therapy, accounting for an estimated 25-40% of outpatient physical therapy visits. One strategy commonly used for treating LBP is directional preference. Directional preference is the process of examining a patient with LBP's response to a movement direction, i.e., extension, and if it coincides with improvement, the test becomes part of the treatment. Various studies have shown evidence for, and use of directional preference by physical therapists. Specifically for LBP, directional preference usually involves either an extension-bias or flexion-bias, with various studies indication an extension protocol being the most common (estimated \> 80% of patients). With extension exercises, a favorable therapeutic effect result in centralization of symptoms (leg pain migrates proximal), improved range of motion (ROM), decreased pain and decreased fear of movement. In recent years there has been an increased interest in various pain neuroscience strategies to help people in pain, including LBP. It is well established that the physical body of a person is represented in the brain by a network of neurons, often referred to as a representation of that particular body part in the brain. This representation refers to the pattern of activity that is evoked when a particular body part is stimulated. The most famous area of the brain associated with representation is the primary somatosensory cortex (S1). These neuronal representations of body parts are dynamically maintained. It has been shown that patients with pain display different S1 representations than people with no pain. The interesting phenomenon associated with cortical restructuring is the fact that the body maps expand or contract, in essence increasing or decreasing the body map representation in the brain. Furthermore, these changes in shape and size of body maps seem to correlate to increased pain and disability. Various studies have shown that physical movement is associated with restoring the cortical maps, which in turn may be associated with a decreased pain experience. In patients with high levels of pain, sensitization of the nervous system and fear of movement, physical movement itself may increase a pain experience. An added therapeutic ability to help restore these cortical maps is motor imagery (visualization). Various studies have shown that motor imagery activate the same areas of the brain as when actually physically moving, thus restoring the altered maps "without moving."

* Patient arrive to physical therapy with low back pain (physician referral or self-referral) * Patient complete standard clinic medical and insurance intake forms * Based on the intake forms, patients are screened by the physical therapists against the inclusion criteria and if met, asked to participate in the study * Upon agreement, a written consent is signed * Patients complete research intake forms: * Demographic information * Age * Gender * Duration of LBP * Location of LBP (body chart with grid allocation) * Pain rating (NPRS): Numeric Pain Rating Scale * Fear-Avoidance (Physical and Work Subscales) (FABQ) * Pain Catastrophization Scale (PCS) * Patients undergo a standard physical therapy interview * Patients undergo a standard physical therapy examination * Patients undergo a directional preference test to determine if they are potentially responsive to extension exercises * Once patients are shown to be responsive to extension, they are alternately allocated to receive motor imagery of extension exercises (experimental group; \[EG\]) or physical extension exercises (control group, \[CG\]). * Prior to the treatment lumbar extension ROM will be measured via a standardized procedure * Upon completion of the tests, patients will receive one of two allocated treatments Following the treatment, patients will undergo repeat measures of: * Spinal extension ROM * Pain rating * Fear of movement * Pain catastrophization Patients will be asked to return to physical therapy in 2 to 3 days (standard care) Upon return, measurements will be repeated of: * Pain rating * Fear of movement * Pain catastrophization * Spinal extension ROM This marks the end of data collection (and study) of the individual patient - Following the tests the patient is treated per the discretion of the therapist as the data collection has been completed