title: Effect of lumbar spinal manipulation on local and remote pressure pain threshold and pinprick sensitivity in asymptomatic individuals: a randomised trial.
abstract: BACKGROUND
  The mechanisms of clinical pain relief associated with spinal manipulative therapy (SMT) are poorly understood. Our objective was to determine whether lumbar high-velocity low-amplitude SMT altered pressure pain threshold (PPT) and pinprick sensitivity (PPS) locally and remotely, how long any change lasted (up to 30 min), and whether changes related to the side of SMT.
  
  
  METHODS
  Thirty-four asymptomatic participants (mean age 22.6 years ±4.0) received a right- or left-sided lumbar SMT. PPT and PPS were measured bilaterally at the calf, lumbar spine, scapula, and forehead before and immediately, 10, 20, and 30 min after intervention. Data were collected between October 2014 and June 2015.
  
  
  RESULTS
  Bilateral calf and lumbar spine PPT increased significantly after 10 - 20 min and was maintained at 30 min (7.2-11.8 % increase). PPS decreased significantly in all locations at various times (9.8 - 22.5 % decrease). At the calf and lumbar spine, PPT increased slightly more ipsilateral to the SMT than contralateral.
  
  
  CONCLUSIONS
  Lumbar SMT reduced deep pressure sensitivity locally and in the lower limbs for at least 30 min, whereas sensitivity to pinprick was reduced systemically. These findings suggest that SMT specifically inhibits deep pressure sensitivity distally. These findings are novel compared to other lumbar SMT studies, and may reflect a local spinal or complex supraspinal analgesic mechanism.
  
  
  BACKGROUND
  Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000682640).
authors.affiliation: Discipline of Chiropractic, School of Health Professions, Murdoch University, 90 South Street, Murdoch, WA 6155 Australia.
authors.forename: Sasha L
authors.initials: SL
authors.lastname: Dorron
authors.affiliation: Discipline of Chiropractic, School of Health Professions, Murdoch University, 90 South Street, Murdoch, WA 6155 Australia.
authors.forename: Barrett E
authors.initials: BE
authors.lastname: Losco
authors.affiliation: Discipline of Psychology, School of Psychology and Exercise Science, Murdoch University, 90 South Street, Murdoch, WA 6155 Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Drummond
authors.affiliation: Discipline of Chiropractic, School of Health Professions, Murdoch University, 90 South Street, Murdoch, WA 6155 Australia.
authors.forename: Bruce F
authors.initials: BF
authors.lastname: Walker
keywords: Lumbar spine; Pain sensitivity; Pinprick sensitivity; Pressure pain threshold; Spinal manipulative therapy