The cervical spine can be divided into upper and lower units, each making a different contribution to the magnitude of rotation and proprioception. However, few studies have examined the effect of the cervical-rotation positions on proprioception.
To compare cervical-spine rotation active joint-position sense (AJPS) near midrange of motion (mid-ROM; 30°) and near end-ROM (60°).
Human performance research laboratory.
53 military helicopter pilots (age 28.4 ± 6.2 y, height 175.3 ± 9.3 cm, weight 80.1 ± 11.8 kg).
Main Outcome Measures:
A motion-analysis system was used to record cervical-rotation kinematics. Subjects sat in a chair wearing a headband and blindfold. First, they actively rotated the head right or left to a target position (30°/60°), with real-time verbal cues provided by the tester. Subjects held the target position for 5 s and then returned to the start position. After this, they replicated the target position as closely as possible. Five trials were performed in both directions to both target positions (R30/R60/L30/L60). Order of direction/position was randomized. The difference between target and replicated positions was calculated and defined as absolute error (AE), and the mean of 5 trials was used for analyses. Wilcoxon signed-ranks tests were used to compare AJPS at the different target positions (P < .0125 with Bonferroni adjustments).
End-ROM AEs were significantly more accurate than mid-ROM AEs (P = .001).
Cervical-spine-rotation AJPS is more accurate near end-ROM than mid-ROM. Both target positions should be used to examine cervical-spine-rotation AJPS of both the upper and lower units.
Nagai is with the Dept of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA. Clark is with the School of Sport, Health and Applied Science, St Mary’s University, London, UK. Abt, Heebner, and Lephart are with the College of Health Sciences, University of Kentucky, Lexington, KY. Sell is with the Dept of Orthopaedic Surgery, Duke University, Durham, NC. Smalley is with US Army Aeromedical Activity, Fort Rucker, AL. Wirt is with the US Army Institute of Surgical Research, Fort Sam Houston, TX.