Additive Effects of Combined Spinal Manipulations on Pain Pressure Threshold
Condition: Pain Threshold
Study type: Interventional

Summary: 
      Physical therapists frequently use spinal manipulation therapy (SMT) to treat spinal pain.
      However, the methods by which SMT exerts its effects are not well understood. The aim of this
      study is to assess potential changes in pain pressure threshold following both a cervical and
      lumbar spine manipulation in a single treatment session at sites local and diffuse to the
      site of manipulation application. This study will also attempt to determine if the order of
      the cervical and lumbar manipulation application impacts pain pressure threshold changes.
    

Detailed description: 
      The aim of the proposed study is to add to the literature pertaining to the effects of spinal
      manipulation on PPT. To date, no studies have assessed whether or not there is an additive
      effect of multiple manipulations during a single treatment session on PPT. The proposed study
      will assess potential changes in PPT between baseline measurements, following a single
      cervical or lumbar manipulation, and after the delivery of second spinal manipulation
      performed on a different segment. The study design will allow for the investigation of
      possible additive effects, as well as for the effect of the first manipulation to be assessed
      independently of the second. Order of delivery of the cervical and lumbar manipulation will
      be randomized among participants to allow investigators to consider the possibility that the
      order of the manipulations impacts PPT changes.

      Research Questions

        1. Is a single spinal manipulation of either the cervical or lumbar spine associated with
           an immediate increase in pain pressure threshold either locally or diffusely when
           compared to a no treatment control?

        2. What is the effect of a second spinal manipulation at a different segment immediately
           following the first spinal manipulation on pain pressure threshold?

        3. Is there a difference based on the order of which spinal manipulation is administered
           (cervical first, then lumbar; lumbar first, then cervical) on post-intervention local
           and diffuse pain pressure threshold?

      Overview of Research Design This study will be a cross-sectional, single-blinded randomized
      control trial. This will be a single session, experimental approach in which participants who
      meet the inclusion/exclusion criteria will be divided into three groups: treatment group 1,
      treatment group 2, and control group. Group assignment will be performed using randomized
      concealed allocation. Participants will undergo pain pressure threshold testing using
      pressure algometry, followed by a cervical manipulation for treatment group 1 and a lumbar
      manipulation for treatment group 2. The control group will rest quietly for an allotted
      amount of time. Upon completion of the first intervention, a second pain pressure threshold
      assessment will be performed. Treatment group 1 will then receive a lumbar manipulation,
      while treatment group 2 receives a cervical manipulation. The control group will again rest
      quietly. Following the second intervention, a final pain pressure threshold assessment will
      be taken. The primary dependent measures will be 1) current pain intensity as reported by a
      verbal numeric pain rating scale, 2) self-reported stiffness, and 3) pain pressure threshold
      measured in Newtons.
    

Intervention name(s): Spinal Manipulation
Intervention type(s): Procedure
Intervention description(s): A spinal manipulation is a high velocity, low amplitude thrust through a physiological barrier in order to elicit a cavitation.
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Single (Investigator)
Primary purpose: Basic Science
Keywords: Pain Threshold