The Role of the Rate of Force Application in Responses to Spinal Manipulation Therapy

Neuromechanical Response to Spinal Manipulation Therapy: Effects of a Constant Rate of Force Application

The objective of the present study is to determine if spinal manipulations with a constant rate of force application but with different peak force and time to peak force lead to similar responses in healthy adults.

Although there are indirect evidences that the rate of force application modulates neuromuscular responses to spinal manipulation therapy (SMT) through peak force or thrust duration modulations, such an assumption remains to be confirmed. Therefore, the objective of the present study was to determine if different SMT force-time profiles where a constant rate of force application would be maintained (through the modulation of the peak force and the time to peak force) lead to similar neuromechanical responses. Based on the available data relative to the effect of SMT biomechanical parameters modulation, it was hypothesized that neuromuscular responses would be similar across SMT force-time profiles, while vertebral displacements would increase as SMT peak force increases.

Inclusion Criteria:

• Healthy adult

Exclusion Criteria:

• Thoracic or lumbar pain
• History of back trauma or surgery
• Severe osteoarthritis
• Inflammatory arthritis
• Vascular conditions
• Contraindication to the use of SMT