Chronic neck pain is one of today’s most prevalent pathologies. The International Classification of Diseases categorizes four subgroups based on patients’ associated symptoms. However, this classification does not encompass upper cervical spine dysfunction. The aim is to compare the short- and mid-term effectiveness of adding a manual therapy approach to a cervical exercise protocol in patients with chronic neck pain and upper cervical spine dysfunction. Fifty-eight subjects with chronic neck pain and upper cervical spine dysfunction were recruited (29 = Manual therapy + Exercise; 29 = Exercise). Each group received four 20-min sessions, one per week during four consecutive weeks, and a home exercise regime. Upper flexion and flexion-rotation test range of motion, neck disability index, craniocervical flexion test, visual analogue scale, pressure pain threshold, global rating of change scale, and adherence to self-treatment were assessed at the beginning, end of the intervention and at 3- and 6-month follow-ups. The Manual therapy + Exercise group statistically improved short- and medium-term in all variables compared to the Exercise group. Four 20-min sessions of Manual therapy + Exercise along with a home-exercise program is more effective in the short- to mid-term than an exercise protocol and a home-exercise program for patients with chronic neck pain and upper cervical dysfunction.

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This study compares upper cervical spine range of motion (ROM) in the three cardinal planes before and after occiput-atlas (C0–C1) stabilization. After the dissection of the superficial structures to the alar ligament and the fixation of C2, ten cryopreserved upper cervical columns were manually mobilized in the three cardinal planes of movement without and with a screw stabilization of C0–C1. Upper cervical ROM and mobilization force were measured using the Vicon motion capture system and a load cell respectively. The ROM without C0–C1 stabilization was 19.8° ± 5.2° in flexion and 14.3° ± 7.7° in extension. With stabilization, the ROM was 11.5° ± 4.3° and 6.6° ± 3.5°, respectively. The ROM without C0–C1 stabilization was 4.7° ± 2.3° in right lateral flexion and 5.6° ± 3.2° in left lateral flexion. With stabilization, the ROM was 2.3° ± 1.4° and 2.3° ± 1.2°, respectively. The ROM without C0–C1 stabilization was 33.9° ± 6.7° in right rotation and 28.0° ± 6.9° in left rotation. With stabilization, the ROM was 28.5° ± 7.0° and 23.7° ± 8.5° respectively. Stabilization of C0–C1 reduced the upper cervical ROM by 46.9% in the sagittal plane, 55.3% in the frontal plane, and 15.6% in the transverse plane. Also, the resistance to movement during upper cervical mobilization increased following C0–C1 stabilization.

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In this study of nearside oblique impact loading, the PMHS exhibited kinematics characterized by reduced torso pitching and increased lateral head excursion as compared to previous frontal impact results. These kinematics resulted in potential cervical and thoracic spinal injuries and in complete, displaced fractures of the lateral and posterior aspects of the rib cage. Though this is a limited number of subjects, it shows the necessity of further understanding of the kinematics of occupants exposed to this loading mode.

Regulation ECE-22.05/06 does not require a helmet penetration test. Penetration testing is controversial since it has been shown that it may cause the helmet to behave in a non-desirable stiff way in real-world crashes. This study aimed to assess the effect of the penetration test in the impact performance of helmets. Twenty full-face motorcycle helmets were penetration tested at multiple locations of the helmet shell. Then, 10 helmets were selected and split into two groups (hard shell and soft shell) depending on the results of the penetration tests. These 10 helmets were then drop tested at front, lateral, and top areas at two different impact speeds (5 m/s and 8.2 m/s) to assess their impact performance against head injuries. The statistical analyses did not show any significant difference between the two groups (hard/soft shell) at 5 m/s. Similar results were observed at 8.2 m/s, except for the top area of the helmet in which the peak linear acceleration was significantly higher for the soft shell group than for the hard shell group (230 ± 12 g vs. 211 ± 11 g; p-value = 0.038). The results of this study suggest that a stiffer shell does not necessarily cause helmets to behave in a stiffer way when striking rigid flat surfaces. These experiments also showed that hard shell helmets can provide better protection at higher impact speeds without damaging helmet performance at lower impact speeds.

Study Design. Biomechanical study using cadaveric cervical spines. Objective. To evaluate joint mobility and stiffness at the craniovertebral junction. Summary of Background Data. Data on the intersegmental kinematics of the craniovertebral joints are available in the literature with a widespread range of values. The effect that alar ligament injuries have on intersegmental kinematics remains unclear and requires further biomechanical investigation. Methods. Ten occipito-atlanto-axial (C0-C1-C2) human specimens were articulated to flexion, extension, bilateral lateral bending, and bilateral axial rotation. The moment-rotation response was continuously tracked through the entire range of motion before and after unilateral alar ligament transection of the right side.Results. The intersegmental (C0-C1/C1-C2) moment-rotation response was continuously quantified in full flexion (7.2 AE 6.68/ 12.1 AE 5.88), extension (11.1 AE 6.48/3.0 AE 2.88), lateral bending to the right (3.1 AE 2.28/1.6 AE 1.28) and left sides (3.3 AE 1.68/ 2.1 AE 1.58), and axial rotation to the right (1.2 AE 3.58/32.3 AE 9.38) and left sides (2.7 AE 2.68/25.3 AE 8.38). Unilateral alar ligament transection increased the range of motion of C0-C2 in the three planes of movement; however, intersegmental motion alterations were not always observed. Conclusion. Increases in the range of extension and lateral bending at C0-C1, which had not been reported previously, were observed. Further, the range of rotation on the right and left sides increased, in conjunction with the increased ranges at C0-C1 and C1-C2.

Instability is a serious and life-threatening diagnosis in the upper cervical spine (occiput-atlas-axis), and a depth understanding of normal range of movement is required for clinical manual evaluation. To improve this knowledge, ten upper cervical spine specimens have been tested in flexion, extension, lateral bending, and axial rotation.