The effect of neck torsion on postural stability in subjects with persistent whiplash
Dysfunction of cervical receptors in neck disorders has been shown to lead to disturbances in postural
stability. The neck torsion manoeuvre used in the smooth pursuit neck torsion (SPNT) test is thought to
be a specific measure of neck afferent dysfunction on eye movement in those with neck pain. This study
aimed to determine whether neck torsion could change balance responses in those with persistent
whiplash-associated disorders (WADs). Twenty subjects with persistent WAD and 20 healthy controls
aged between 18 and 50 years stood on a computerised force plate with eyes closed in comfortable
stance under 5 conditions: neutral head, head turned to left and right and neck torsion to left and right.
Root mean square (rms) amplitude of sway was measured in the anterioreposterior (AP) and medial
elateral (ML) directions. The whiplash group had significantly greater rms amplitude in the AP direction
following neck torsion compared to the control group (p < 0.03). The results show that the neck torsion
manoeuvre may lead to greater postural deficits in individuals with persistentWAD and provides further
evidence of neck torsion to identify abnormal cervical afferent input, as an underlying cause of balance
disturbances in WAD. Further research is warranted.
The results of this study suggest that the neck torsion manoeuvre may adversely change balance responses in some subjects with persistent WAD and that deficits in standing balance exist particu-larly in the anterioreposterior direction when compared to asymptomatic control subjects. The results also indicate that somatosensory impairment is the most likely cause of the balance disturbances following whiplash. The disturbances are probably related to a combination of proprioceptive and nociceptive factors. Overall, these findings have implications for future studies and for the clinical assessment and management of balance disturbances in persistent whiplash-associated disorders, although, further research with greater subject numbers is required.
Yu L-J, Stokell R, Treleaven J. The effect of neck torsion on postural stability in subjects with persistent whiplash. Manual Therapy. 2011 Aug;16(4):339-43. PubMed PMID: WOS:000293245000006.