Immediate Effect of a Single Cervical Spinal Manipulation
Condition: Neck Pain
MeSH terms: Neck Pain
Study type: Interventional

Summary: 
      Objective: The aim of the present study is to analyze the immediate effect of a single
      cervical spinal manipulation on cervical movement pattern. Further, To perform the sample
      size calculation, the investigators took into consideration that the investigators pretend to
      achieve a medium effect size (d=0.5) of the differences with two groups (EG and CG) and two
      aimed to explore the impact on pain, disability and patient's improvement-perceived
      sensation, comparing with a placebo.

      Methods: The study design is experimental and purposive sampling was used to select the study
      participants. The grouping allocation was randomized. The people volunteer to participate in
      the study, are assigned to the experimental group (EG) that will receive a single
      manipulation, to the control group (CG) that will receive a single placebo treatment.

      The participants will be assessed twice, one before the treatment and the other, after the
      end. Head movement is recorded by means of a video-photogrammetry system from the coordinates
      of a set of eight reflective markers located on a helmet. The movements will be record at 200
      fps.

      In each evaluation, the perceived pain and the neck disability index are also recorded. And
      the impression of change is evaluated only in the second evaluation.

      Outcomes. Pain, Disability of the neck, Impression of Change, Range of motion (RoM), Maximum
      angular velocity (MAV), Maximum angular acceleration (MAA) and Harmonicity (HARM).

      Intervention: The intervention, in both groups, it includes only one session that lasted 15
      minutes approximately: a) Cervical manipulation intervention and b)Placebo intervention.
    

Detailed description: 
      INTRODUCTION Non-specific neck pain is defined as pain in the posterior and lateral aspect of
      the neck between the superior nuchal line and the spinous process of the first thoracic
      vertebra with no signs or symptoms of major structural pathology. It is a common
      musculoskeletal disorder that leads to substantial disability, discomfort, and reduced
      cervical mobility, resulting in enormous health costs in terms of treatment and work
      absenteeism. The American Physical Therapy Association's guidelines on neck pain recommends
      utilizing cervical manipulation (CM) and mobilization procedures to reduce neck pain based on
      strong evidence. Spinal manipulation is defined as "a passive, high velocity, low amplitude
      thrust applied to a joint complex within its anatomical limit with the intent to restore
      optimal motion, function, and/or to reduce pain" and its effectiveness, concretely of a
      continuous program of cervical manipulations (CM), on neck pain has been largely studied. A
      previous systematic review concluded that treatments based on CM are effective both alone and
      in combination with exercises whilst other systematic reviews and an evidence-based guideline
      showed that CM, combined with exercises, resulted to be more effective for neck pain,
      function, and global perceived effect, than a therapeutic program based, exclusively, on CM.

      Nevertheless, the underlying mechanisms of the pain decrease with this therapeutic approach
      are not completely understood. A recent study aimed at analyzing the biomechanics of a single
      CM, used a complex system of synchronized biplane radiographs to measure the facet gapping
      during a single manipulation. Authors demonstrated that target and adjacent motion segments
      undergo facet joint gapping during a manipulation and that segmental and global range of
      motion (ROM) increases in all three planes of motion immediately after one manipulation.

      In the clinical setting, the best of our knowledge, only one previous clinical trial have
      analyzed the effectiveness of a single cervical manipulation on cervical range of motion,
      comparing with placebo, demonstrating an improvement in all the global maximum cervical
      movements, measured with the goniometer. However, pain may affect other movement'
      characteristics beside the maximum range of motion (ROM), as velocity, variability or
      movement harmony.

      Nevertheless, no previous study has analyzed the characteristics of the patients' cervical
      motion pattern after a single manipulation which could provide information about functional
      changes in cervical movements. People with neck pain, has shown more slow movements, less
      harmonic movements in the points close to pain and exponential trend at the ends of the
      range, even when cervical spine motion ranges remain within normal limits.

      The investigators hypothesized that functional assessment of the cervical spine based on the
      analysis of the motion pattern, will let us know if a single manipulation is effective in the
      improvement of those variables.

      The aim of the present study is to analyze the immediate effect of a single cervical spinal
      manipulation on cervical movement pattern. Further, the investigators aimed to explore the
      impact on pain, disability and patient's improvement-perceived sensation, comparing with a
      placebo.

      METHODS Participants The study design is experimental and purposive sampling was used to
      select the study participants. The grouping allocation was randomized. The people volunteer
      to participate in the study, are assigned to the experimental group (EG) that will receive a
      single CM, to the control group (CG) that will receive a single placebo treatment.

      All the participants should meet the following inclusion criteria: perceived pain scored 3 or
      above, in a visual analogue scale, and neck functional status revealing a mild disability.
      Additionally, patients had symptoms duration less than 30 days.

      For both groups, the exclusion criteria include an inflammatory rheumatic disease or an inner
      ear disorder, the use of antidepressant opioid or sedative drugs, current vertigo or
      dizziness, visual loss, neurological disorder, and trunk or shoulder surgery within the past
      year.

      Sample size To perform the sample size calculation, the investigators took into consideration
      to achieve a medium effect size (d=0.5) of the differences with two groups (EG and CG) and
      two assessments (pre and post-treatment). Further, the investigators set a type I error of
      5%, and a type II error of 20%. This power calculation resulted in 17 patients on each group.

      Assessment procedures The participants will be assessed twice, one before the treatment and
      the other, after the end. Head movement is recorded by means of a video-photogrammetry system
      from the coordinates of a set of eight reflective markers located on a helmet. The movements
      will be record at 200 fps.

      Participants sit in a chair with the trunk fixed at the back by means of belts. In each
      session, they perform three movements: flexion-extension (FE), lateral flexion (LB) and axial
      rotation (AR) whose order was randomized. Each movement will be perform seven consecutive
      times without stopping and achieving a continuous and smooth cyclic movement with the maximum
      achievable range at their preferred speed. The participants are encouraged to practice the
      three movements before the test begins, to avoid the learning effect.

      In each evaluation, the perceived pain and the neck disability index are also recorded. And
      the impression of change is evaluated only in the second evaluation.

      Outcomes Pain, with the Visual Analogue Scale (VAS), in which the patients marked their level
      of pain intensity on a 10-cm horizontal line (0= no pain to 10= maximum pain) at the time the
      assessment was carried out.

      Disability of the neck, with the 'Neck Disability Index', a self-report questionnaire used to
      determine how neck pain affects a patient's daily life. Scoring is reported on a 0-50 scale,
      0 being the best possible score.

      Impression of Change, with the self-reported measure 'Patient Global Impression of Change'
      that reflects a patient's belief about the efficacy of treatment.

      Range of motion (RoM): angular excursion of the cervical motion. Maximum angular
      velocity(MAV), it is measured as percentile 95 of angular velocity during the test.

      Maximum angular acceleration(MAA), it is measas percentile 95 of angular acceleration during
      the test.

      Harmonicity (HARM): is the absolute value of the correlation coefficient between two motion.
      Thus HARM quantifies the fit between the actual movement and the simple harmonic motion.

      Intervention The intervention, in both groups, it includes only one session that lasted 15
      minutes approximately. Participants should wear a sleeveless shirt that allows the
      physiotherapist to treat the neck region. Evaluations and manipulations are performed by the
      same experienced physiotherapist.

      Cervical manipulation intervention Prior to intervention, a screened for any signs of
      vertebrobasilar insufficiency is performed by means of the vertebral artery compromise test,
      as well as the root compression test using the Jackson test, and the screening for upper
      cervical spine ligamentous instability through Sharp-Purser test, alar ligament stress test
      and transverse ligament test.

      To perform the evaluation and detect the cervical vertebral level with mobility restriction,
      with the patient in supine position, a cervical examination is carried out to determine the
      mobility restriction, both in flexo-extension, as in inclination and rotation. To check the
      level of restriction, the post-anterior sliding test is performed.

      Once the vertebral levels with restriction have been detected, high speed and low amplitude
      manipulation is carried out based on the location of the pain and the detection of the
      perceived joint hypomobility, using the clinical criterion for this, with a maximum of 2
      manipulative attempts by vertebral level, regardless of having achieved joint cavitation. The
      manipulation is performed following the criteria of thrust manipulations. A maximum of 3
      manipulations are applied in total per subject, one for each level (high level C1-C2, medium
      level C3-C6, and low level C7), if necessary.

      Placebo intervention This group will receive 15 minutes of sham techniques in a supine
      position over the stretcher. First, a series of short-time and no pressure contact with
      physiotherapist´s hands is performed in several points of head and shoulders for 10 minutes.
      Subsequently, light touch is applied on standardized anatomic areas, equal to those treated
      with manipulative intervention, for 2 minutes each time, adding a total duration of
      approximately 15 minutes, similar to the intervention group.

      Statistics Standard statistical methods will be use to obtain the mean and standard deviation
      of the mean (SD). For the inferential analysis of the data, a mixed two-factor multivariate
      analysis of variance (MANOVA) with a between-subject factor 'group' (i.e. CG and EG) ant a
      within-subject factor 'time' with two groups (pre and post-intervention). Multiple comparison
      techniques are performed using Bonferroni correction. The investigators will evaluate the
      assumption of homoscedasticity and it will be assumed in each variable. In addition, the
      investigators will compare the perceived changes after treatment between the two groups with
      an independent Student T test. Type I error will be set as <5% (p <.05).
    

Intervention name(s): Cervical manipulation intervention; Placebo intervention
Intervention type(s): Other; Other
Intervention description(s): Cervical manipulative technique; Sham intervention
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The study design is experimental
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: neck pain; manual therapy; movement