Background / Purpose:

There is an ongoing debate regarding the ability of physical therapists to manually sense intervertebral motion. Physical therapists use intervertebral hypomobility as a clinical indicator for spinal manipulation. Also in question is the mechanism of improvement observed after spinal manipulation. Some argue that the improvement is purely neurophysiologic and unrelated to changes in intervertebral motion. This study aimed to determine the diagnostic accuracy of a physical therapist's manual assessment of lumbar intervertebral motion compared to ultrasound imaging and the effect of lumbar manipulation on intervertebral motion, pain, and disability,

Methods:

Subjects will complete a Numeric Pain Rating Scale (NPR),Oswestry Disability Index (ODI), and a Central Sensitization Inventory before arriving for the study via Qualtrics survey tool. They will be screened for contraindications to manipulation and neurological signs and symptoms. Active forward bending will be quantified by measuring the distance of the subject's fingertips to the floor. Two experienced physical therapists will evaluate the subject's lumbar intervertebral mobility. They will identify the lumbar segment with the least motion or hypomobility. The subjects will be imaged from L1 to S1 with a 5 MHz curvilinear transducer (Edge II MSK ultrasound unit, SonoSite, Inc, Bothell, WA) in the sidlying position with their trunk and hips flexed to end-range. The examiner will save the sagittal image and then place a digital caliper to measure the distance between the spinous processes from the peak of the hyperechoic curvature of the caudal spinous process to the peak of the hyperechoic curvature of the cranial spinous process of each lumbar segment (L5-S1, L4-L5, L3-L2,L2-L1). Subjects will then be randomized to receive a high-velocity low amplitude thrust manipulation or a sham manipulation. The lumbar spine will be reimaged. The ultrasound examiner will be blinded to the manipulation and the caliper measurements. Finally, subjects will be asked for their Global Rating of Change (GROC) and to actively bend forward to remeasure the distance of their fingertips to the floor. One week later, patients will receive an e-mail containing links to repeat the NPR, GROC, and ODI.

Inclusion Criteria:

• 18 years old to 60 years old
• Individuals with mechanical low back pain who have limited spine mobility without signs of nerve root involvement.

Exclusion Criteria:

Subjects cannot participate in this study if they:

• ever had any type of spinal surgery
• ever had a spinal infection
• ever had a fracture in your spine
• recently had an episode of acute physical trauma ie a motor vehicle accident or a fall and - were not evaluated by a medical practitioner.
• are apprehensive about their spine being manipulated
• have osteoporosis or have been on corticosteroids for an extended period of time
• have Rheumatoid Arthritis
• have Marfans Syndrome or Ehlers-Danlos Syndrome
• currently have cancer or any other illness
• have a bleeding disorder or are now on blood thinning medications
• have symptoms of tingling, numbness, or weakness below the knee
• are unable to remain in a sidelying position for at least 30 minutes
• are currently pregnant

Participant: the participants will not know whether they received the lumbar manipulation or sham lumbar manipulation.

Care Provider: the care providers (those who perform the lumbar manipulation and sham lumbar manipulation) will not be involved in collecting any outcome data.

Investigator: all investigators collecting outcome measures will not know which subjects received the lumbar manipulation or sham lumbar manipulation.

Outcome assessor: the outcome assessors will not be involved in collecting data.