Clinical trial NCT01469533: Pressure Pain Thresholds and Basal Electromyographic Activities Following Spinal Mechanical Manipulation
Official title: Changes in Pressure Pain Thresholds and Basal Electromyographic Activities Following Spinal Mechanical Manipulation in Asymptomatic Subjects
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Pain
Keywords: Spine
Manipulation
Pain Threshold
Electromyography.
Lead sponsor: RenJi Hospital
Sponsor class: OTHER
First posted: 2011-11-10
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to investigate if the application of spinal mechanical manipulation on low back region resulted in changes in pressure pain thresholds (PPT) in asymptomatic subjects and the extent of the hypoalgesia; whether it is local, regional or systemic. Simultaneously, the investigators are to further explore the phenomenon of reduced sEMG activity after spinal mechanical manipulation to better understand the immediate effects of mechanical manipulation on low back region.

Detailed description: Spinal manipulation (SM) is used by clinicians for the treatment of several chronic pain conditions. The effectiveness of different spinal manipulations targeted at the lumbar spine in patients with low back pain is supported by an increasing number of high-quality randomized clinical trials1and systematic reviews. Although these techniques have shown some effectiveness in clinical practice, most of clinical studies solely investigated the effects of spinal manipulation on overall reports of pain and function and the underlying mechanisms by which manipulation produce clinical effects remain largely unknown.

The neurophysiologic mechanisms by which manipulation inhibits pain, however, are matters of speculation and still under investigation. Proposed hypotheses have suggested that manipulation has the potential to remove the source of mechanical pain or induce stimulus-produced analgesia. Spinal manipulation induces sufficient force to simultaneously activate both superficial and deep somatic mechanoreceptors, proprioceptors, and nociceptors. The effect of this stimulation is a strong afferent segmental barrage of spinal cord sensory neurons, capable of altering the pattern of afferent input to the central nervous system and inhibiting the central transmission of pain. Other suggested mechanisms have been the activation of the endogenous opiate system, the alteration of the chemical mediators or the effects of joint cavitation. An understanding of the mechanism by which manipulations cause a hypoalgesic response is subject to further research and is currently far from complete. A review of the literature found several studies exploring immediate changes in mechanical pain sensitivity provoked by spinal manipulative procedures. Mobilisation/manipulation to the cervical spine has been shown to provide a hypoalgesic effect as measured by pressure pain thresholds (PPTs) in patients suffering from mechanical neck pain and lateral epicondylalgia. A hypoalgesic effect has also been demonstrated following mobilization to peripheral joints in the upper and lower limbs. Mobilizations to the lumbar spine have been shown to produce an immediate and significant widespread hypoalgesic effect in asymptomatic subjects However, Perry et al. that found unilateral mobilizations on the lumbar spine respectively had side specific response.

Besides analgesic effect, it has been presented spinal manipulation can reduce the increased resting muscle tone or spasm, which can be monitored by surface electromyography (sEMG). If the presence of a hypertonic muscle is functionally associated with a spinal dysfunction that is correctable by SM, it would consequently follow that the associated higher EMG level would diminish after appropriate SM. In a descriptive study DeVocht JW et al. found that manipulation induces an immediate change, usually a reduction, in resting EMG level in patients with low back pain. Herzog J reported the observation of a single but very dramatic decrease in resting EMG activity in thoracic musculature within 1 second of SM. One possible segmental mechanism could be that the manipulation may induce a reflex muscle relaxation by modifying proprioceptive group 1 and 2 afferents. However, few randomly controlled trials have directly investigated the effect of spinal mechanical manipulation on basal electromyographic activity (BEA) in asymptomatic subjects.

Spinal mechanical manipulation has been widely used in clinical manual therapy. However, because mechanical thrusts usually produce no cavitations, whether mechanical techniques produce the same hypoalgesic effects and muscle relaxation as manual techniques remains untested. To further elucidate the physiologic mechanisms associated with spinal mechanical manipulation, it is essential to investigate its effects in asymptomatic individuals who do not have any active central sensitization. In fact, recent studies have supported the use of asymptomatic subjects in studies related to neurophysiological mechanisms of spinal manipulations. Further research is therefore required to clarify if there is a hypoalgesic effect or muscle relaxation in response to spinal mechanical manipulation in the lumbar region in asymptomatic subjects.

Eligibility criteria: Inclusion Criteria:

* asymptomatic volunteers
* age from 18 to 60 years

Exclusion Criteria:

* aversion to manual contact
* symptoms in the low back or lower extremities
* previous history of spine surgery
* receiving any manual therapy within the past 1 month before the study
* any contraindication to manipulation
* regular use of analgesic or anti-inflammatory drugs

Primary outcomes:
measure: Pressure pain threshold assessment
timeFrame: within 10 minutes immediately after manipulation
Secondary outcomes:
measure: Basal electromyographic activity
timeFrame: within 10 minutes immediately after manipulation
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Renji Hospital
state: Shanghai
Study officials:
affiliation: RenJi Hospital
name: Xiangrui Wang
role: STUDY_DIRECTOR
References:
citation: Giles LG, Muller R. Chronic spinal pain: a randomized clinical trial comparing medication, acupuncture, and spinal manipulation. Spine (Phila Pa 1976). 2003 Jul 15;28(14):1490-502; discussion 1502-3. doi: 10.1097/00007632-200307150-00003.
citation: Lawrence DJ, Meeker W, Branson R, Bronfort G, Cates JR, Haas M, Haneline M, Micozzi M, Updyke W, Mootz R, Triano JJ, Hawk C. Chiropractic management of low back pain and low back-related leg complaints: a literature synthesis. J Manipulative Physiol Ther. 2008 Nov-Dec;31(9):659-74. doi: 10.1016/j.jmpt.2008.10.007.
citation: Boal RW, Gillette RG. Central neuronal plasticity, low back pain and spinal manipulative therapy. J Manipulative Physiol Ther. 2004 Jun;27(5):314-26. doi: 10.1016/j.jmpt.2004.04.005.
citation: Cramer G, Budgell B, Henderson C, Khalsa P, Pickar J. Basic science research related to chiropractic spinal adjusting: the state of the art and recommendations revisited. J Manipulative Physiol Ther. 2006 Nov-Dec;29(9):726-61. doi: 10.1016/j.jmpt.2006.09.003.
citation: Vernon H. Qualitative review of studies of manipulation-induced hypoalgesia. J Manipulative Physiol Ther. 2000 Feb;23(2):134-8. doi: 10.1016/s0161-4754(00)90084-8.
citation: de Camargo VM, Alburquerque-Sendin F, Berzin F, Stefanelli VC, de Souza DP, Fernandez-de-las-Penas C. Immediate effects on electromyographic activity and pressure pain thresholds after a cervical manipulation in mechanical neck pain: a randomized controlled trial. J Manipulative Physiol Ther. 2011 May;34(4):211-20. doi: 10.1016/j.jmpt.2011.02.002. Epub 2011 Mar 21.
citation: Fernandez-Carnero J, Fernandez-de-las-Penas C, Cleland JA. Immediate hypoalgesic and motor effects after a single cervical spine manipulation in subjects with lateral epicondylalgia. J Manipulative Physiol Ther. 2008 Nov-Dec;31(9):675-81. doi: 10.1016/j.jmpt.2008.10.005.
citation: DeVocht JW, Pickar JG, Wilder DG. Spinal manipulation alters electromyographic activity of paraspinal muscles: a descriptive study. J Manipulative Physiol Ther. 2005 Sep;28(7):465-71. doi: 10.1016/j.jmpt.2005.07.002.
citation: Fernandez-de-Las-Penas C, Alonso-Blanco C, Cleland JA, Rodriguez-Blanco C, Alburquerque-Sendin F. Changes in pressure pain thresholds over C5-C6 zygapophyseal joint after a cervicothoracic junction manipulation in healthy subjects. J Manipulative Physiol Ther. 2008 Jun;31(5):332-7. doi: 10.1016/j.jmpt.2008.04.006.