Maximal voluntary isometric neck strength deficits in adults with whiplash associated disorders and association with pain and fear of movement.
From: J Orthop Sports Phys Ther. 2009 Mar;39(3):179-87
This was a controlled laboratory study using a cross-sectional, repeated-measures design to quantify maximal voluntary isometric neck forces in healthy subjects and individuals with whiplash associated disorder, using an objective measurement system to evaluate the test-retest properties of these strength measurements and to assess the links between neck strength, pain, kinesiophobia, and catastrophizing in patients with whiplash associated disorder.
The prognosis of whiplash associated disorder is difficult to predict due to a lack of objective measurement methods and to our limited understanding of the role of psychological factors in the development of chronic whiplash associated disorder symptoms.
Fourteen subjects with chronic whiplash associated disorder grade I or II and an age-matched, healthy group (n = 28) participated in this study. Cervical strength was measured with the Multi-Cervical Unit in 6 directions, and pain was measured with a visual analog scale. Individuals in the whiplash associated disorder group completed the Neck Disability Index, the Tampa Scale for Kinesiophobia, and the Pain Catastrophizing Scale.
Significant deficits in strength were observed for the individuals in the whiplash associated disorder group compared to the healthy group, particularly in extension, retraction, and left lateral flexion. The Multi-Cervical Unit demonstrated good intratester reliability for the healthy group and the whiplash associated disorder group, and small standard errors of measurement for both groups. No significant association was found between neck strength and Neck Disability Index, Tampa Scale for Kinesiophobia, and Pain Catastrophizing Scale.
The Multi-Cervical Unit demonstrated good test and retest properties for healthy subjects and individuals with whiplash associated disorder. Neck strength was lower in individuals with whiplash associated disorder; however, the strength deficits were not clearly linked with psychological factors.
