Background: Sensory and motor system dysfunctions have been documented in a proportion of
patients with acute whiplash associated disorders (WAD). Sensorimotor incongruence may occur and
hence, may explain pain and other sensations in the acute stage after the trauma.
Objectives: The present study aimed at 1) evaluating whether a visually mediated incongruence
between sensory feedback and motor output increases symptoms and triggers additional sensations
in patients with acute WAD, 2) investigating whether the pattern of sensations in response to
sensorimotor incongruence differs among patients suffering from acute and chronic WAD, and
healthy controls.
Study Design: Experimental study.
Setting: Patients with acute WAD were recruited within one month after whiplash injury via the
emergency department of a local Red Cross medical care unit, the Antwerp University Hospital, and
through primary care practices. Patients with chronic WAD were recruited through an advertisement
on the World Wide Web and from the medical database of a local Red Cross medical care unit.
Healthy controls were recruited from among the university college staff, family members, and
acquaintances of the researchers.
Methods: Thirty patients with acute WAD, 35 patients with chronic WAD, and 31 healthy persons
were subjected to a coordination test. They performed congruent and incongruent arm movements
while viewing a whiteboard or mirror.
Results. Twenty-eight patients with acute WAD reported sensations such as pain, tightness, feeling
of peculiarity, and tiredness at some stage of the test protocol. No significant differences in frequencies
and intensities of sensations were found between the various test stages (P > .05). Significantly more
sensations were reported during the incongruent mirror stage compared to the incongruent control
stage (P < .05). The pattern in intensity of sensations across the congruent and incongruent stages
was significantly different between the WAD groups and the control group.
Limitations: The course and prognostic value of susceptibility to sensorimotor incongruence after
an acute whiplash trauma are not yet clear from these results. A prospective longitudinal study with
an expanded study population is needed to investigate if those with a lowered threshold to visually
mediated sensorimotor incongruence in the acute stage are at risk to develop persistent pain and
disability.
Conclusion: Patients with acute WAD present an exacerbation of symptoms and additional
sensations in response to visually mediated changes during action. These results indicate an altered
perception of distorted visual feedback and suggest altered central sensorimotor nervous system
processing in patients with acute WAD.
Key words: Sensorimotor incongruence, visually mediated changes, whiplash, sensations, acute
pain, chronic pain, altered central sensorimotor processing, central nervous system.
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