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.

Objective: The objective of this article is to analyze the kinematics and dynamics of restrained postmortem human surrogates (PMHS) exposed to a nearside oblique impact and the injuries that were found after the tests. Methods: Three male PMHS of similar age (64 ± 4 years) and anthropometry (weight: 61 ± 9.6 kg; stature: 172 ± 2.7 cm) were exposed to a 30° nearside oblique impact at 34 km/h. The test fixture approximated the seating position of a front seat occupant. A rigid seat was designed to match the pelvic displacement in a vehicle seat. Surrogates were restrained by a 3-point seat belt consisting of a 2 kN pretensioner (PT), 4.5 kN force-limiting shoulder belt, and a 3.5 kN PT lap belt. The shoulder belt PT was not fired in one of the tests. Trajectories of the head, shoulder, and hip joint (bilaterally) were recorded at 1,000 Hz by a 3D motion capture system. The 3D acceleration and angular rate of the head, T1, and pelvis, and the 3D acceleration of selected spinal locations was measured at 10,000 Hz. Seat belt load cells measured the belt tension at 4 locations. PMHS donation and handling were performed with the approval of the relevant regional ethics review board. Results: Activation of the shoulder PT reduced substantially the peak forward excursion of the head but did not influence the lateral displacement of the head center of gravity (CG). In all 3 subjects, the lateral excursion of the head CG (291.1, 290, 292.1 mm) was greater than the forward displacement (271.4, 216.7, 171.5 mm). The hip joint excursion of the PMHS that was not exposed to the shoulder PT seat belt was twice the magnitude observed for the other 2 subjects. The 3 PMHS sustained clavicle fractures on the shoulder loaded by the seat belt and 2 of them were diagnosed atlantoaxial subluxation in the radiologist examination. Avulsion fractures of the right lamina of T1, T2, T3, and T4 were found when the PT was not used. The 3 PMHS received multiple fractures spread over both aspects of the rib cage and involving the posterior aspect of it. Conclusion: 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.

Previous studies indicate that maximum upper cervical axial rotation occurs only through a combination of transverse, frontal, and sagittal plane motions. This study explores the relationship between transection of the alar ligament and combined upper cervical axial rotation movements. Ten cryopreserved upper cervical spines were manually mobilized in bilateral axial rotation and two different motion combinations with simultaneous motion in the three anatomical planes: rotation in extension (extension + axial rotation + contralateral lateral bending) and rotation in flexion (flexion + axial rotation + ipsilateral lateral bending). These three motions were performed before and after right alar ligament transection. The occiput-axis axial rotation was measured using an optical motion capture system while measuring the applied load. With intact alar ligament, the axial rotation in flexion showed the lowest range of motion (right, R: 9.81 ± 3.89°; left, L: 15.54 ± 5.89°). Similar results were found between the other two mobilizations: axial rotation (R: 33.87 ± 6.64°; L: 27.99 ± 6.90°) and rotation in extension (R: 35.15 ± 5.97°; L: 28.96 ± 6.47°). After right alar ligament transection, rotation in flexion (particularly in left rotation) showed the largest increase in motion: rotation in flexion (R: 13.78 ± 9.63°; L: 23.04 ± 5.59°), rotation in extension (R: 36.39 ± 7.10°; L: 31.71 ± 7.67°), and axial rotation (R: 38.50 ± 9.47°; L: 31.59 ± 6.55°). Different combinations of movements should be evaluated when analyzing the maximum axial rotation of the upper cervical spine, as axial rotation alone and rotation in extension showed a larger range of motion than rotation in flexion. After unilateral alar ligament injury, rotation to the non-injured side in flexion demonstrates the most movement increase.

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.

Head trauma is frequently related to the misuse of drinking vessels as weapons. Forensic reports usually evaluate these blunt injuries as having occurred in scenarios where the alcohol intake is high. Fatal consequences are seen in blows with glass bottles aiming at the head. To prove the outcome that a glass bottle thrown to the head could cause, three intact human cadaver heads were impacted with 1-liter glass bottles at 9.5 m/s using a drop-tower. The impact location covered the left temporal bone, sphenoid bone, and zygomatic arch. The contact between the head and the bottle was produced at an angle of 90° with (1) the valve of the bottle, (2) the bottom of the bottle, and (3) with the head rotated 20° in the frontal plane touching again with the bottom of the bottle. The three bottles remained intact after the impact, and the injury outcomes were determined by computed tomography (CT). The alterations were highly dependent on the impact orientation. The outcome varied from no injury to severe bone fractures. In the most injurious case (#3), fractures were identified in the cranial base, sphenoid bone, and zygomatic bone. These testing conditions were selected to replicate one specific legal case, as required by the plaintiff. Physical disputes with bar glassware can lead to complex combinations of blunt and sharp-force injuries. Controlled biomechanical studies can benefit forensic analyses of violence involving glassware by providing a better understanding of the underlying injury mechanisms.

Current body armor design evaluation is based on legacy backface deformation criteria for protection despite limited medical basis. This uniform protection approach, which does not account for anatomical and physiological variability within the torso, may result in heavy armors that limit Warfighter mobility. To optimize armor design, anatomical and physiological regional injury tolerances must be assessed through live animal experimentation. Prior to this, the animal and human must first be compared to determine the animal model's viability as a surrogate for thoracoabdominal behind armor blunt trauma (BABT) response. Here, 74 BABT impacts were conducted using ten midsized male postmortem human subjects (PMHS) and ten 40-kg porcine cadavers in matched testing conditions over the lungs, liver, and sternum. Injury risk functions were generated from experimental data and compared across surrogates at each body region. The PMHS and 40-kg porcine cadaver correlated well for chest wall injuries in the lung region, and similarities were noted in high-severity impacts to the liver. Further, assessment of the backface intrusion injury risk function showed regional tolerance differences between anatomical regions, highlighting the need for separate region-specific design criteria. These results indicate that the 40-kg porcine cadaver was an appropriate torso surrogate for certain PMHS regions, such as the ribcage overlaying the lungs and the liver, in BABT conditions. As this study used cadaveric tissue, future studies should investigate the physiological components of BABT-induced injury in a live animal model, focusing on quantifying regional injury tolerances toward armor design optimization.