• Fear Avoidance Beliefs Questionnaire, physical subscale [ Time Frame: 6 weeks, 3 months, 6 months ] [ Designated as safety issue: No ]
• Visual Analogue Scale for Pain [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• Postural Sway [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• SF-36, v1, Physical Function subscale [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• Posteroanterior Spinal Stiffness [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• Sit-to-Stand Maneuver [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• Spinal Manipulation [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]

The purpose of this study is to compare the clinical effectiveness of two types of chiropractic spinal manipulation to conservative medical care for patients at least 55 years old with sub-acute or chronic low back pain (LBP).

Despite the high prevalence of LBP and the associated economic costs, disability, and lost productivity, and despite the development of several treatment guidelines, one of which recommends chiropractic spinal manipulation for some subgroups of patients with pack pain, the management of LBP remains controversial and highly variable across professions and geographic regions. Although one recent publication describes the design of chiropractic and exercise for seniors with low back or neck pain, no published studies to our knowledge, have assessed the effectiveness of chiropractic manipulation compared to medical care for older adults with sub-acute or chronic low back pain.

• Subacute Low Back Pain
• Chronic Low Back Pain

• Other: Spinal manipulation
  High-velocity low amplitude spinal manipulation (HVLA-SM)
• Other: Spinal manipulation
  Low-velocity variable amplitude spinal manipulation (LVVA-SM)
• Drug: Usual medical care (Celebrex, Aleve, Bextra, Naproxen)
  Celebrex: po, 200mg, qd, six weeks; Aleve: po, 220mg, bid, six weeks; Bextra: po, 10mg, qd, six weeks; Naproxen: po, 500mg, bid, six weeks.

• 1: Experimental
  High-velocity low amplitude spinal manipulation (HVLA-SM)
  Intervention: Other: Spinal manipulation
• 2: Experimental
  Low-velocity variable amplitude spinal manipulation (LVVA-SM)
  Intervention: Other: Spinal manipulation
• 3: Active Comparator
  Usual medical care
  Intervention: Drug: Usual medical care (Celebrex, Aleve, Bextra, Naproxen)

Inclusion Criteria:

• Age 55 or older
• Idiopathic low back pain (LBP) of at least four weeks duration
• Meet the diagnostic classification of 1, 2, or 3 according to the Quebec Task Force on Spinal Disorders

Exclusion Criteria:

• Low back pain (LBP) not meeting Quebec Task Force Diagnostic Classifications 1, 2 or 3, especially LBP associated with: frank radiculopathy, altered lower extremity reflex, dermatomal sensory deficit, progressive unilateral muscle weakness or motor loss, symptoms of cauda equina compression, and CT or MRI evidence of anatomical pathology (e.g. abnormal disc, lateral or central stenosis.
• Co-morbid conditions or general poor health that could significantly complicate the prognosis of LBP, including pregnancy, bleeding disorders, extreme obesity, and clear evidence of narcotic or other drug abuse.
• Major clinical depression defined as scores greater that 29 on the Beck Depression Inventory - Second Edition
• Bone or joint pathology that contraindicate spinal manipulative therapy of joint pathology that contraindicate spinal maniuplative therapy of the arthropathies and significant osteoporosis
• Pacemaker, because there are safety issues with equipment used to collect data in the biomechanical testing laboratory
• Current or pending litigation related to current episode of LBP.
• Receiving disability for any health-related condition
• Spinal Manipulative care for any reason within the past month
• Unwilling to postpone use of manual therapies for LBP except those provided in the study for the duration of the study period.
• Unable to read or verbally comprehend English.