title: Impaired visual perception of hurtful actions in patients with chronic low back pain.
abstract: Visually presented biological motion stimuli activate regions in the brain that are also related to musculo-skeletal pain. We therefore hypothesized that chronic pain impairs the perception of visually presented actions that involve body parts that hurt. In the first experiment, chronic back pain (CLBP) patients and healthy controls judged the lifted weight from point-light biological motion displays. An actor either lifted an invisible container (5, 10, or 15 kg) from the floor, or lifted and manipulated it from the right to the left. The latter involved twisting of the lower back and would be very painful for CLBP patients. All participants recognized the displayed actions, but CLBP patients were impaired in judging the difference in handled weights, especially for the trunk rotation. The second experiment involved discrimination between forward and backward walking. Here the patients were just as good as the controls, showing that the main result of the first experiment was indeed specific to the sensory aspects of the task, and not to general impairments or attentional deficits. The results thus indicate that the judgment of sensorimotor aspects of a visually displayed movement is specifically affected by chronic low back pain.
authors.affiliation: Psychology, Westf. Wilh.-Univ. Münster, Fliednerstraße 21, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience (OCC), Münster, Germany. Electronic address: lussanet@wwu.de.
authors.forename: Marc H E
authors.initials: MH
authors.lastname: de Lussanet
authors.forename: Frank
authors.initials: F
authors.lastname: Behrendt
authors.forename: Christian
authors.initials: C
authors.lastname: Puta
authors.forename: Tobias L
authors.initials: TL
authors.lastname: Schulte
authors.forename: Markus
authors.initials: M
authors.lastname: Lappe
authors.forename: Thomas
authors.initials: T
authors.lastname: Weiss
authors.forename: Heiko
authors.initials: H
authors.lastname: Wagner
mesh_terms: D000328:Adult; D000368:Aged; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D020918:Complex Regional Pain Syndromes / Q000451:nursing / Q000503:physiopathology / Q000523:psychology; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology*; D017116:Low Back Pain / Q000503:physiopathology* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009619:Nociceptors / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010147:Pain Measurement; D016059:Range of Motion, Articular / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D055139:Sensory Gating / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D016138:Walking / Q000502:physiology; D014891:Weight Lifting / Q000502:physiology*
keywords: 2323; 2330; 2340; 3299; 3360; 4-week pain intensity; 4WPI; CLBP; CRPS; RT; VAS; Weight judgment; chronic low back pain; complex regional pain syndrome; response time; visual analog scale