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Published on: March 12, 2021
Cervical flexion and extension includes anti-directional cervical joint motion in healthy adults
Xu Wang1, René Lindstroem2, Maciej Plocharski3
1Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health and Science Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark; Department of Orthopedics, The Second Hospital of Jilin University, Changchun 130021, People's Republic of China.
Background Context:
Anti-directional cervical joint motion has previously been demonstrated. However, quantitative studies of anti-directional and pro-directional cervical flexion and extension motions have not been published.
Purpose:
This study aimed for a quantitative assessment of directional and anti-directional cervical joint motion in healthy subjects.
Study Design:
An observational study was carried out.
Patients Sample:
Eighteen healthy subjects comprised the study sample.
Outcome Measures:
Anti-directional and pro-directional cervical flexion and extension motion from each cervical joint in degrees were the outcome measures.
Methods:
Fluoroscopy videos of cervical flexion and extension motions (from neutral to end-range) were acquired from 18 healthy subjects. The videos were divided into 10% epochs of C0/C7 range of motion (ROM). The pro-directional and anti-directional motions in each 10% epoch were extracted, and the ratios of anti-directional motions with respect to the pro-directional motions (0%=no anti-directional movement) were calculated for joints and 10% epochs.
Results:
The flexion and extension ROM for C0/C7 were 51.9°±9.3° and 57.2°±12.2°. The anti-directional motions of flexion and extension ROM constituted 42.8%±9.7% and 41.2%±8.2% of the respective pro-directional movements. For flexion, the first three joints (C0/C1, C1/C2, C2/C3) demonstrated larger ratios compared with the last three joints (C4/C5, C5/C6, C6/C7) (p<.03). For extension, C1/C2 and C2/C3 ratios were larger compared with C0/C1, C4/C5, and C5/C6 (p<.03). Comparisons between flexion and extension motions showed larger C0/C1 ratio but smaller C5/C6 and C6/C7 ratios in extension (p<.05).
Conclusions:
This is the first report of quantified anti-directional cervical flexion and extension motion. The anti-directional motion is approximately 40% of the pro-directional motion. The results document that large proportions of anti-directional cervical flexion and extension motions were normal.
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