The Impact of Spinal Manipulation on Leg Movement in Lumbar Spinal Stenosis Patients

METHODOLOGY:

A non-surgical spine care clinician, (physical therapist or chiropractor) who is not the principal investigator, will rule out, through physical examination and history, any further contraindications to lumbar spinal manipulation (SM) prior to intervention. The physical examination will consist of orthopedic tests typically used in clinical practice prior to spinal manipulation intervention. No intervention will be delivered by the principal investigator.

Upon arrival participants will provide consent to the research assistants by filling out the Research Participant Information and Consent Form. They will then complete a battery of questionnaire based outcome measures including a 2 quadruple numeric rating scales (QNRS), one for each left, and right leg pain, the Swiss Spinal Stenosis score (SSS)(Stucki, Daltroy, Liang et al 1996) and the Waterloo Footededness Questionnaire - revised (WFQ-R) (Elias, Bryden, Bulman-Fleming 1998) on a computer. The width and length of the distal pad of the great toe will be measured bilaterally.

Apparatus:

A 23" projected image will be positioned lengthwise in front of the participant on a surface, parallel to the floor but facing the ceiling, on a custom built support frame and platform. A microswitch will be mounted in the support frame platform on the edge proximal to the participant and will serve as the home position. Custom software (E-prime, v 2.0 Psychology Software Tools Inc., Sharpsburg, PA) will be used to generate the projected images, to track switch initiated timing, and trigger/synchronize 3-dimensional movement recording. An infrared emitting diode (IRED), (Northern Digital, Waterloo, ON) will be mounted to the distal aspect of the great toe using a custom removable brace.

Procedure:

With bare feet participants will stand on the platform with their great toe pad depressing a microswitch identified as the "home" key. A visual precue (black cross in the center of the projected image) will alert the participant that the next trial is about to begin at a variable time (2000-2550 ms) after the precue. They will be asked to reach forward (in the sagittal plane) with their great toe pad to touch the center of targets generated on the computer touch screen as "quickly and accurately as possible". These will be discrete foot aiming movements. Targets will appear on the screen's surface with widths of either 2.5 cm, 5 cm and will require movement amplitudes of 20 cm, and 50 cm for contact. The combination of distance, and target width will be used to determine the index of difficulty for the task. Each of the 4 possible combinations used will generate 4 different indices of difficulty (ID) 3a, 4a, 4b, and 5 bits (IDs 4a, and 4b overlap but consist of different target width/distance combinations). The 4 combinations will be presented in a random order, with each combination being presented 10 times, for a total of 40 trials. Once completed for one foot the procedure will be repeated with the opposite foot, resulting in a total of 80 trials. To reduce the risk of potential falls, participants will wear a gait belt (Ross Flexi Belt) and there is a railing adjacent to the platform. Participants will be allowed to sit and rest between feet if needed. Each round of trials should require less than 10 minutes to perform. The order of foot use will be randomly assigned. The touch surface, toe mounted IRED, and platform surface will be disinfected between participants.

Participants will then have their active lumbar range-of-motion (ROM) quantified using electrogoniometry/torsiometry (Biometrics Ltd, Ladysmith, VA) and be randomized to either SM or NI groups. Based on group assignment they will respectively either receive either bilateral high-velocity low-amplitude (HVLA) SM directed toward the lumbar region by a licensed clinician, or wait 5 minutes as a non-intervention. The HVLA lumbar SM procedure delivered will be a hypothenar spinous pull (Peterson, Bergman, 2002). The presence or absence audible joint cavitation following SM will be anecdotally recorded. The NI group will be kept blinded as to whether they may receive SM later during the study. All participants will have their active lumbar range of motion reassessed immediately following intervention (or NI), have their NRS for low back and leg pain repeated, and then perform an additional 80 trials of the foot pointing task again (with an experimenter blinded to the intervention participants received).

Statistical Tests:

Separate paired student's t-tests will be used to compare participants to themselves in terms of left to right baseline QNRS scores, NRS scores pre and post intervention, and lumbar ROM in each axis of movement pre and post intervention. Separate unpaired student's t-tests will compare questionnaire based outcome measure scores between groups, and lumbar ROM in each axis of movement pre and post intervention between groups.

For all behavioural and kinematic measures separate 2 Group (SM, NI) x 2 Limb (left, right) x 4 ID mixed model analysis of variance (ANOVA) designs will be employed. Post hoc analysis will be performed on effects involving more than two means as needed using Tukey's Honestly Significant Difference (HSD).

Adverse Events/Serious Adverse Events:

As this study requires clinical intervention, the following adverse events could be possible: post-treatment soreness and/or exacerbation of existing low back symptoms. Such events may or may not occur following spinal manipulation.

Planned Dissemination:

The results of this study will be prepared for dissemination first at relevant clinical and scientific conferences. Subsequently, this work will be submitted to a peer reviewed journal for consideration of publication.

Additional Ethical Aspects of Protocol:

Potential Benefits to Participants and Others:

The potential benefits of participation to participants include receiving $10 parking reimbursement, and a $5 Tim Hortons gift card. The patient may have increased range of motion and decreased low back pain as a result of clinical intervention. The information learned from this study will benefit others with lumbar spinal stenosis in the future.

Indirect benefits include knowledge that they have contributed to the advancement of scientific understanding of the effect of spinal manipulation on the measurement of movement outcomes in a population with LSS.

There are no direct benefits to others. Indirect benefits include those to the scientific community through the planned dissemination of the work. The results of this study will be prepared for dissemination first at relevant clinical and scientific conferences. Participants have the option (not mandatory) of providing an email address on their consent form if they wish to know the outcome of the study. Subsequently, this work will be submitted to a peer reviewed journal for consideration of publication.

Potential harms to Participants and Others:

The stenosis population could possibly experience fatigue or discomfort related to their pre-existing leg or low back pain. In an attempt to minimize such events trial durations will be kept brief and participants will be allowed to sit and rest between trials if needed.

As this study requires clinical intervention, the following adverse events could be possible: post-treatment soreness and/or exacerbation of existing low back symptoms. Such events may or may not occur following spinal manipulation. A licensed clinician with more than five years of experience will be on hand.

To protect participant privacy all data collected will be coded and put into database format. All data will be de-identified and kept on a single study computer at each site which is password protected and located in a locked office. As such, access to study subject information/data will be highly safeguarded and can only be accessed by Dr. Passmore. Any paper forms and questionnaires will be kept in a locked cabinet in a locked room. Identifying information that will be collected is the subject's name, contact information and date of birth.