Quantitative posturography in altered sensory conditions: a way to assess balance instability in patients with chronic whiplash injury.
OBJECTIVE
To quantify neck mobility and posture with and without various postural perturbations.


METHODS
A multivariable 2-group study with repeated measures and treatments.


METHODS
A human performance laboratory.


METHODS
Eleven patients with chronic whiplash injury (mean age, 33.3+/-6.7 y; weight, 73.4+/-11.4 kg; height, 173.3+/-7.2 cm) with a sex- and age-matched control group (mean age, 33.1+/-6.8 y; weight, 68+/-12.5 kg; height, 171.5+/-6.3 cm).


METHODS
Neck mobility and the effects of postural perturbations affecting the visual, vestibular, cutaneous, proprioceptive, and nociceptive systems were measured.


METHODS
Active range of motion, neck position sense, and postural activity.


RESULTS
We found significantly reduced neck mobility and increased postural activity in the patient group compared with the control group. In patients, there was significantly greater postural activity with eyes closed, eyes open and speaking, and eyes closed with Achilles' tendons vibrations compared with eyes open with no vibrations. In the controls, there was no significant effect of experimental muscle pain on postural activity.


CONCLUSIONS
Patients with chronic whiplash injury had a protective response to neck movement and different tuning, sequencing, and execution of the postural synergies probably because of excessive reliance on visual input despite a possible deficit and altered vestibular and/or proprioceptive activity. In healthy volunteers, the pain induced by a single bolus injection of hypertonic saline was probably too limited in intensity and spreading to decrease postural stability.
Madeleine
Pascal
P
Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark. pm@smi.auc.dk
Prietzel
Hanne
H
Svarrer
Heine
H
Arendt-Nielsen
Lars
L
D000328:Adult; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009333:Neck / Q000503:physiopathology*; D019547:Neck Pain / Q000139:chemically induced / Q000503:physiopathology; D004856:Postural Balance / Q000502:physiology*; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage / Q000009:adverse effects; D012683:Sensory Deprivation / Q000502:physiology*; D020069:Shoulder Pain / Q000139:chemically induced / Q000503:physiopathology; D014911:Whiplash Injuries / Q000503:physiopathology*
D012462:Saline Solution, Hypertonic