Modifying Lumbar Flexion Pain Thresholds in Chronic LBP Using Virtual Reality and Visual-Proprioceptive Manipulation

This study investigates the potential to modify movement-evoked pain in individuals with chronic low back pain (LBP) by manipulating visual proprioceptive feedback through virtual reality (VR). The research aims to explore how altering the perception of movement through VR can influence pain experiences and motor behavior. A total of 50 patients with non-specific chronic LBP are planned to participate.

Participants will perform lumbar spine flexion movements until the onset of pain under three experimental conditions: (1) accurate visual feedback, without virtual reality (control); (2) underestimated movement feedback (F-), where the VR displays 20% less movement than performed; and (3) overestimated movement feedback (F+), where the VR shows 20% more movement than actually executed. These conditions are designed to evaluate how changes in visual feedback impact pain perception and range of motion (ROM).

Lumbar ROM will be objectively measured using a 3-space Fastrack motion analysis system to ensure precise tracking of movement. The study also seeks to identify whether individuals with higher levels of pain, kinesiophobia (fear of movement), or catastrophising (an exaggerated negative mindset about pain) are more susceptible to VR feedback manipulation.

Various psychological and physical metrics will be assessed using validated tools, including pain thresholds, pain intensity, kinesiophobia, and catastrophising levels. This comprehensive approach aims to identify patient subgroups who may benefit most from VR-based interventions and to shed light on the mechanisms by which altered visual feedback modifies pain perception and motor behavior in chronic LBP.

Inclusion criteria

• Participants of both sexes.
• Aged between 18 and 65 years.
• Diagnosed with non-specific chronic low back pain (according to the European COST B13 guidelines).
• Presence of lumbar extension limitation.

Exclusion criteria

• Diagnosis of a spinal tumor.
• Presence of a spinal infection or fracture.
• Diagnosed systemic diseases.
• Diagnosis of fibromyalgia.
• Presence of cauda equina syndrome.
• History of prior spinal surgery.
• Musculoskeletal injuries of the lower extremities (including: sciatica; radiating pain in the lower extremities; symptoms of numbness or weakness in the lower extremities)