Objectives: The long-term goal of our study is to improve the understanding of the biological mechanisms associated with spinal manipulative therapy (SMT) in low back pain.Methods: This project involved a pilot randomized, blinded clinical trial (ClinicalTrials.gov registration number NCT03078114) of 3-week SMT in chronic nonspecific low back pain (CNSLBP) patients. We recruited 29 participants and randomly assigned them into either a SMT (n = 14) or sham SMT (n = 15) group. Pre- and postintervention, we quantified the effect of SMT on clinical outcomes (Numeric Pain Rating Scale and Oswestry Disability Index) and pressure pain threshold (PPT) at local (lumbar spine), regional (lower extremity), and remote (upper extremity) anatomical sites.Results: We observed a significant main effect for time signifying reduced hypersensitivity (increased PPT) at local (p = .015) and regional (p = .014) locations at 3 weeks. Furthermore, we found significant main effects of time indicating improvements in pain (p < .001) and disability (p = .02) from baseline among all participants regardless of intervention. However, no between-group differences were observed in PPT, clinical pain, or disability between the SMT and sham SMT groups over 3 weeks.Conclusions: After 3 weeks of SMT or sham SMT in CNSLBP patients, we found hypoalgesia at local and remote sites along with improved pain and low back-related disability.Level of Evidence: 1b.
OBJECTIVE: The purpose of this study was to compare the immediate effects in asymptomatic participants of manual and instrument-assisted cervical manipulation on pressure pain thresholds, pressure pain perception, and muscle mechanical properties (tone, stiffness, and elasticity) over muscles anatomically related and unrelated to the manipulated level.
METHODS: Fifty-nine asymptomatic participants (34 women and 25 men; age [mean ± standard deviation] = 21.1 ± 1.6 years) were randomly assigned to 4 groups in a double-blind, randomized, placebo-controlled trial. Two groups received cervical (C3/C4) manipulation, 1 manual and the other instrument-assisted; the third group received a sham manipulation; and the fourth group served as the control. Bilateral pressure pain threshold, pressure pain perception, muscle tone, stiffness, and elasticity in the upper trapezius and biceps brachii were evaluated before and immediately after the interventions.
RESULTS: At baseline, there were no differences among the groups on any variable. After the interventions, a significant increase in pressure pain threshold was observed with both manual and instrument-assisted manipulation at local and distal sites (P < .05), whereas no changes were observed in either the control or the placebo group. The perception of pain pressure did not change significantly in any group. The interventions did not promote any statistically significant differences in muscle tone, elasticity, or stiffness at any site (local or distal).
CONCLUSION: Cervical (C3/C4) manual and instrument-assisted manipulations produced an increase in pressure pain threshold bilaterally and over muscles related and unrelated to the vertebral segment, but had no effect on muscle tone, elasticity, or stiffness.
BACKGROUND: According to the American Physical Therapy Association, there is strong evidence to show that vertebral mobilization and manipulation procedures can be used to improve spinal and hip mobility and reduce pain and incapacity in low back pain patients that fit the clinical prediction rule.
OBJECTIVES: To evaluate the immediate effects of high-velocity low-amplitude (HVLA) manipulation on pain and postural control parameters in individuals with nonspecific low back pain.
METHODS: This study used a participant-blinded and assessor-blinded randomized controlled clinical trial involving a single session, in which 24 participants were randomly distributed into control (simulated manipulation) and intervention (HVLA lumbar manipulation) groups. The primary (pain: subjective pain intensity and pressure pain threshold) and secondary outcomes (postural control: ellipse area, center of pressure [COP] excursion, COP RMS velocity, and differences between the COP and center of projected gravity) were evaluated before and after the session using a numerical pain scale, algometer, and a force platform. For all outcomes, multiple mixed 2 (group) × 2 (time) ANOVAs were performed.
RESULTS: For the subjective pain intensity, only time was significant as a main effect, where pre-intervention presented a greater value then post-intervention (F [1.44] = 4.377; p = 0.042; r = 0.30). For the pressure pain threshold no significant effect was found. For the postural control parameters, as a main effect, only the ellipse area was significantly greater in the control group (F [1.44] = 6.760; p = 0.013; effect size = 0.36).
CONCLUSIONS: There was a reduction in subjective pain intensity, evaluated using a numerical scale, in both the intervention and control groups immediately after the intervention, suggesting that the spinal manipulation had a similar effect to the placebo procedure. No effect of HVLA lumbar manipulation was identified for postural control variables in either the intervention or control groups.
TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov under the number NCT02312778, registered at 14 September 2014.
BACKGROUND: Spinal manipulation (SM) has been shown to have an effect on the pressure pain threshold (PPT) in asymptomatic subjects, but SM has never been compared in studies on this topic to a validated sham procedure. We investigated the effect of SM on the PPT when measured i) in the area of intervention and ii) in an area remote from the intervention. In addition, we measured the size and duration of the effect.
METHOD: In a randomized cross-over trial, 50 asymptomatic chiropractic students had their PPT measured at baseline, immediately after and every 12 min after intervention, over a period of 45 min, comparing values after SM and a previously validated sham. The trial was conducted during two sessions, separated by 48 h. PPT was measured both regionally and remotely from the 'treated' thoracic segment. Blinding of study subjects was tested with a post-intervention questionnaire. We used mixed linear regression with the baseline value and time as co-variates. If a significant difference were found between groups, then an effect size would be calculated using Cohen's d or Hedge's h coefficient. Statistical significance was set at p < 0.05.
RESULTS: Study subjects had been successfully blinded. No statistically significant differences were found between SM and sham estimates, at any time or anatomical location.
CONCLUSION: When compared to a valid sham procedure and with successfully blinded subjects, there is no regional or remote effect of spinal manipulation of the thoracic spine on the pressure pain threshold in a young pain-free population.
BACKGROUND: Changes in quantitative sensory tests have been observed after spinal manipulative therapy (SMT), particularly in pressure pain thresholds (PPT) and temporal summation (TS). However, a recent systematic review comparing SMT to sham found no significant difference in PPT in patients with musculoskeletal pain. The sham-controlled studies were generally low quality, and conclusions about other quantitative sensory tests could not be made.
OBJECTIVES: We aimed to perform a sham-controlled study with the specific objective of investigating changes in PPT and TS short-term after lumbar SMT compared to sham manipulation in people with low back pain.
METHODS: This was a double-blind randomised controlled trial comparing high-velocity low-amplitude lumbar SMT against sham manipulation in participants with low back pain. Primary outcome measures were PPT at the calf, lumbar spine and shoulder, and TS at the hands and feet. These were measured at baseline, then immediately, 15 min and 30 min post-intervention.
RESULTS: Eighty participants (42 females) were included in the analyses (mean age 37 years), with 40 participants allocated to each intervention group. Significant between-group differences were only observed for calf PPT, which could be explained by a decrease in PPT (increased sensitivity) after SMT and an increase after sham. Feet TS decreased significantly over time after both SMT and sham, and any other changes over time were inconsistent.
CONCLUSIONS: Our results suggest that lumbar SMT does not have a short-term hypoalgesic effect, as measured with PPT and TS, when compared to sham manipulation in people with low back pain.
BACKGROUND: Most of the research on the effects of spinal manipulation on endocrine function has been done on healthy subjects and has yielded contradictory results. The potential role of cervical manual therapy intervention in order to induce changes in the endocrine system has not yet been investigated.
AIM: The aim of this trial is to compare the effects on salivary cortisol levels and clinical outcomes of cervical manipulation versus cervical mobilization or sham manipulation in patients with chronic mechanical neck pain.
DESIGN: Randomized controlled trial.
SETTING: University of Alcala de Henares: outpatient (referrals from office workers).
POPULATION: A total of 83 patients with chronic mechanical neck pain.
METHODS: Participants were randomized to receive one session of cervical manipulation, cervical mobilization, or sham manipulation. The measured variables were salivary cortisol levels, neck pain and disability, pressure pain thresholds (PPT), and cervical range of motion (ROM). They were obtained at baseline, immediately after treatment (except neck disability), and at one-week follow-up (except cortisol).
RESULTS: A significant and comparable increase in cortisol levels was observed immediately after cervical manipulation and mobilization (both P<0.001). Neck disability improved to a similar degree in the cervical manipulation and mobilization groups at the one-week follow-up (both P<0.001). Neck pain was reduced immediately after cervical manipulation (P<0.001), cervical mobilization (P=0.001), and sham manipulation (P<0.001). There were no significant changes in most ROM directions after either treatment. No significant interaction effect was observed for PPT.
CONCLUSIONS: Cervical manipulation and mobilization resulted in a similar increase in cortisol concentrations immediately post-treatment in people with chronic mechanical neck pain. Supraspinal mechanisms may thus play a role in the hypoalgesic effects that follow the application of both interventions.
CLINICAL REHABILITATION IMPACT: The increase in cortisol levels was similar with cervical manipulation and mobilization so induced stress levels can be similar in both interventions.
OBJECTIVES: Individuals with neck pain experience disrupted grip force control when performing manipulative tasks. Manipulative physical therapy might decrease pain and change the activity of surrounding muscles; however, its effect on upper limb motor control remains undetermined. This study aims to analyze the effects of cervical manipulation on pressure pain threshold (PPT), upper extremity muscle activity along with grip force control in individuals with neck pain.
METHODS: Thirty subjects with neck pain were instructed to grasp and lift an object before and after cervical (n = 15) or sham (n = 15) manipulation. The patients' PPT, electromyographic (EMG) activity of the upper extremity/scapular muscles, and grip force control were analyzed before and after one session of manipulation.
RESULTS: No significant differences were found in the grip force control, PPT and EMG activity variables between groups.
DISCUSSION: These results suggest that a single session of cervical manipulation may not modify upper limb motor control, more specifically grip force control and EMG activity, in patients with cervical pain. Future studies should investigate potential changes in grip force control in patients with different features of neck pain and/or by applying long-term treatment.
LEVEL OF EVIDENCE: 1b.
OBJECTIVE: To compare the effects of two different mobilization techniques and a placebo intervention applied to the thoracic spine on heart rate variability (HRV) and pressure pain threshold (PPT) in asymptomatic individuals.
METHODS: Sixty healthy asymptomatic subjects aged between 18 and 40 years old were randomized to a single session of one of the three interventions: posterior-to-anterior (PA) rotatory thoracic passive accessory intervertebral mobilization (PAIVM) (PA group), unilateral thoracic PA in slump position (SLUMP group) or placebo intervention (Placebo group). HRV and PPT at C7 and T4 spinous process, first dorsal interossei muscles bilaterally, and muscle belly of tibialis anterior bilaterally were measured before and immediately after the intervention. A univariate analysis of covariance (ANCOVA) adjusted for baseline values assessed the effect of "Group". Pairwise comparisons with Bonferroni adjustment for multiple comparisons were performed.
RESULTS: There were no significant between-group differences for HRV. A significant between-group difference for PPT in the ipsilateral tibia was found favoring the SLUMP group in comparison with the PA group. There were no significant between-group differences for PPT in the other landmarks.
CONCLUSION: A single treatment of thoracic PAIVM in prone lying and slump position did not alter PPT and HRV compared to placebo in asymptomatic subjects.
OBJECTIVE: The purpose of the current randomized clinical trial was to examine the effects of cervical thrust manipulation or sham manipulation on cervicocephalic kinaesthetic sense, pain, pain-related disability, and pressure pain sensitivity in patients with mechanical neck pain.
METHODS: Fifty-four individuals with neck pain were randomly assigned to receive either a cervical manipulation (right or left) or a sham manipulation. Immediate outcomes included cervical kinesthetic sense as assessed by joint position sense error (JPSE) and pressure pain thresholds (PPTs). At 1 week, neck pain intensity (numerical pain rate scale) and neck pain-related disability (Neck Disability Index [NDI]) outcomes were also collected.
RESULTS: The mixed-model analysis of covariance revealed a significant group × time interaction in favor of the cervical thrust manipulation group for the JPSE on rotation and extension. There was also a significant interaction for changes in PPTs at C5 to C6 and tibialis anterior. At the 1-week follow-up, a significant interaction existed for neck-related disability but not for neck pain at rest, worst pain, or lowest pain experienced the preceding week.
CONCLUSIONS: Our results suggest that cervical spine thrust manipulation improves JPSE, PPT and NDI in participants with chronic mechanical neck pain. Furthermore, changes in JPSE and NDI were large and surpass published minimal detectable changes for these outcome measures. In addition, the effect sizes of PPTs were medium; however, only C5 to C6 zygapophyseal joint exceeded the minimal detectable change. In contrast, cervical thrust manipulation did not improve neck pain intensity at 1 week after the intervention.
BACKGROUND: Cervical and thoracic spinal manipulative therapy has shown positive impact for relief of pain and improve function in non-specific mechanical neck pain. Several attempts have been made to compare their effectiveness although previous studies lacked a control group, assessed acute neck pain or combined thrust and non-thrust techniques.
AIM: To compare the immediate effects of cervical and thoracic spinal thrust manipulations on mechanosensitivity of upper limb nerve trunks and grip strength in patients with chronic non-specific mechanical neck pain.
DESIGN: Randomized, single-blinded, controlled clinical trial.
SETTING: Private physiotherapy clinical consultancy.
POPULATION: Eighty-eight subjects (32.09±6.05 years; 72.7% females) suffering neck pain (grades I or II) of at least 12 weeks of duration.
METHODS: Participants were distributed into three groups: 1) cervical group (N.=28); 2) thoracic group (N.=30); and 3) control group (N.=30). One treatment session consisting of applying a high-velocity low-amplitude spinal thrust technique over the lower cervical spine (C7) or the upper thoracic spine (T3) was performed, while the control group received a sham-manual contact. Measurements were taken at baseline and after intervention of the pressure pain threshold over the median, ulnar and radial nerves. Secondary measures included assessing free-pain grip strength with a hydraulic dynamometer.
RESULTS: No statistically significant differences were observed when comparing between-groups in any of the outcome measures (P>0.05). Those who received thrust techniques, regardless of the manipulated area, reported an immediate increase in mechanosensitivity over the radial (both sides) and left ulnar nerve trunks (P<0.05), and grip strength (P<0.001). For those in the control group, right hand grip strength and pain perception over the radial nerve also improved (P≤0.025).
CONCLUSIONS: Low-cervical and upper-thoracic thrust manipulation is no more effective than placebo to induce immediate changes on mechanosensitivity of upper limb nerve trunks and grip strength in patients with chronic non-specific mechanical neck pain.
CLINICAL REHABILITATION IMPACT: A single treatment session using cervical or thoracic thrust techniques is not enough to achieve clinically relevant changes on neural mechanosensitivity and grip strength in chronic non-specific mechanical neck pain.
Objectives: The long-term goal of our study is to improve the understanding of the biological mechanisms associated with spinal manipulative therapy (SMT) in low back pain.Methods: This project involved a pilot randomized, blinded clinical trial (ClinicalTrials.gov registration number NCT03078114) of 3-week SMT in chronic nonspecific low back pain (CNSLBP) patients. We recruited 29 participants and randomly assigned them into either a SMT (n = 14) or sham SMT (n = 15) group. Pre- and postintervention, we quantified the effect of SMT on clinical outcomes (Numeric Pain Rating Scale and Oswestry Disability Index) and pressure pain threshold (PPT) at local (lumbar spine), regional (lower extremity), and remote (upper extremity) anatomical sites.Results: We observed a significant main effect for time signifying reduced hypersensitivity (increased PPT) at local (p = .015) and regional (p = .014) locations at 3 weeks. Furthermore, we found significant main effects of time indicating improvements in pain (p < .001) and disability (p = .02) from baseline among all participants regardless of intervention. However, no between-group differences were observed in PPT, clinical pain, or disability between the SMT and sham SMT groups over 3 weeks.Conclusions: After 3 weeks of SMT or sham SMT in CNSLBP patients, we found hypoalgesia at local and remote sites along with improved pain and low back-related disability.Level of Evidence: 1b.
