Cervical Flexion Position Research Articles

Association between Occupation and Cervical Disc Degeneration in 1211 Asymptomatic Subjects.

Magnetic resonance imaging (MRI) system has frequently observed degenerative changes in the cervical discs of healthy subjects. Although there are concerns regarding the link between an individual’s occupation and intervertebral disc degeneration (IDD) in the cervical spine, whether the occupation affects IDD is still not clear. This study aimed to evaluate the occupation and IDD interplay using cervical spine MRI among a cohort of healthy individuals, and to evaluate any association between the type of labor and IDD. Using MRI, we prospectively measured at every level, the anteroposterior (AP) intervertebral disc diameter and disc height, in a cohort of 1211 healthy volunteers (606 (50%) male; mean age, 49.5 years). Using a minimum of 100 male and female each from the third to eighth decades of age (20–79 years), IDD was evaluated based on the modified Pfirrmann classification system to derive a disc degeneration score (DDS). We also measured the AP diameters of disc protrusion and of the dural sac as well as the spinal cord. The overall DDS and number of disc protrusions increased with age. Among 11 occupations, there were no significant differences in AP diameter of the dural sac as well as the spinal cord. For the four labor types (heavy object handling, same position maintenance, cervical extension position, and cervical flexion position), there were no significant differences in overall DDS and number of disc protrusions, with or without work. Also, among the four labor types, there were no significant differences in the AP diameter of the dural sac as well as the spinal cord. In this cross-sectional survey of cervical spine MRI data among healthy adult volunteers, occupation and type of labor might have no effect on IDD in the cervical spine.

Effects of Electronic Devices on Vision in Students Age Group 18-25

Purpose: To increase understanding about the damaging effects of light rays on eyesight. To investigate frequency of people affected from light rays electronic devices. Study design: Cross sectional study. Place and Duration of Study: Riphah International University Lahore and duration of study was six months from June 2020 to December 2020. Materials & Methods: A six months cross sectional study with convenient sampling method was conducted at Riphah international university Lahore from June 2020 to December 2020. The age of the individuals was between 18 years–25 years. Individuals who fulfill the inclusion criteria were chosen from University. A proforma was filled regarding detailed history of use of electronic devices other visual problems associated with it. Results: In present study 200 students were participated who has been using electronic devices. In this 100 students were male and 100 were females. 60% were emmetropic, 27.5% were myopic, 5.5% were hyperopia and 7.0% were astigmatic. 40% individuals were using smartphones from 11 years-13 years, 20.5% using from 8 years-11 years and 25% using from 4 years-7 years. The purpose of using these electronic devices in 96 individuals was using smartphone only for social networking. Most of them (130) participants were using smartphone and laptops. Usage of these electronic devices for more than 4 hours–6 hours was observed in 60 members. Among these individuals most of them were using these electronic devices by lying on the bed and some were also using in cervical flexion position. Conclusion: The overall research identified the smartphone / any electronic devices used so longer had bad effect on vision most particularly myopia occurred. This research suggests that constant and extreme utilization of smartphone and other electronic devices should be avoided.

Global sagittal spinal alignment at cervical flexion in patients with dropped head syndrome

Dropped head syndrome (DHS) is characterized by the passively correctable chin-on-chest deformity. The characteristic feature is emphasized in the cervical flexion position. The purpose of this study was to analyze the influence of cervical flexion on sagittal spinal alignment in patients with DHS. The study included 15 DHS subjects and 55 cervical spondylosis (CS) subjects as the control group. The following parameters were analyzed: cervical sagittal vertical axis (C-SVA), occipitoaxial angle (O-C2A), C2 slope (C2S), C2-C7 angle (C2-C7A), T1 slope (T1S), sagittal vertical axis, T1-T4 angle (T1-T4A), T5-T8 angle (T5-T8A), T9-T12 angle, lumbar lordosis, sacral slope, and pelvic tilt, in cervical flexion and neutral positions. The values of C-SVA, O-C2A, C2S, and T1S were significantly different between CS and DHS at cervical neutral and flexion positions. C2-C7A showed significant difference in cervical neutral position, but the difference disappeared in flexion position. T1-T4A did not present a significant difference, but T5-T8A showed a difference in neutral and flexion positions. Malalignment of DHS extended not only to cervical spine but also to cranio-cervical junction and thoracic spine, except T1-T4. It is known that global sagittal spinal alignment is correlated with adjacent parameters, although in DHS the reciprocal change was lost from cranio-cervical junction to the middle part of thoracic spine at cervical flexion.

The evaluation on neural status of cervical spinal cord in normal and Hirayama disease using diffusion tensor imaging.

To explore the changes in diffusion tensor imaging (DTI) parameters in cervical spinal cord in Hirayama disease (HD) patients and healthy volunteers and to compare these parameters between cervical flexion and neutral positions in HD patients. Seventeen male patients with HD and eleven healthy young males were included to receive DTI scans in cervical flexion and neutral positions. The FA and ADC values of different levels were measured based on the region of interest drawn on the mid-sagittal plane. The dynamic compressed level's parameters were defined as the lowest and the second lowest FA and the highest and the second highest ADC, respectively. The clinical assessment of patients was obtained using their disabilities of the arm, shoulder and hand (DASH) scores. For the HD patients, the FA values in the cervical flexion position were lower and the ADC values were much higher than those in the cervical neutral position. Compared with the controls, the ADC values were significantly higher in the lower levels (C5/6-C7/T1) and the FA values obviously lower at C7/T1 in HD patients in cervical neutral position. The FA and ADC values of the dynamic compressed level in HD patients deviated significantly from the average of the lower levels in controls. Both the FA and ADC values of the dynamic compressed level correlated with the DASH scores (FA, R2 = 0.520, P = 0.001; ADC, R2 = 0.421, P = 0.005). DTI parameters can support a hypothesis of dynamic cervical flexion compression and noninvasively reveal the neural status of HD patients. These slides can be retrieved under Electronic Supplementary Material.

Progress in clinical related research of Hirayama disease

Hirayama disease (HD), also known as juvenile muscular atrophy of the distal upper extremity, is featured by concealed onset clinically and often occurs in male adolescence. In most cases, one or both of the asymmetrical distal muscles of the upper extremities are weak and atrophied without objective sensory abnormalities and this disease naturally stops developing after several years. Early Hirayama disease is similar to motor neuron diseases in clinical symptoms like amyotrophic lateral sclerosis. The limitation of medical diagnostic techniques and the lack of understanding by clinicians lead to a higher rate of misdiagnosis of Hirayama disease, making their treatment plan and prognosis completely different. Therefore, a timely and accurate diagnosis of Hirayama disease is essential. In recent years, domestic and foreign scholars conducted researches in the diagnosis of Hirayama disease mainly through clinical manifestation combined with the magnetic resonance imaging of the cervical flexion position and the application of various neurophysiological detection techniques. As the number of clinical cases gradually increases, Hirayama disease draws more attention of clinicians and there are more and more reports and researches on related cases. With the development of research and application of imaging and neuroelectrophysiological techniques, the importance and effectiveness of early diagnosis and treatment of the disease have been affirmed and emphasized, thus people acquire a better understanding of its pathogenesis, clinical diagnosis and treatment. Especially for those suspected patients with juvenile muscular atrophy of the distal upper extremity, it is more important to be vigilant against the possibility of Hirayama disease. Based on this reality, this paper will discuss the new understanding and research progress of pathogenesis, clinical diagnosis and treatment of Hirayama disease, which is very important for clinicians to better understand and pay more attention to this disease.

Changes in muscular strength based on full cervical flexion

We present our study of influence full cervical flexion position on the changes in muscle strength of the upper extremities. This position is typical for a person working on mobile phone or iPad. The purpose of the study was determination of the connection between change of the head flexed position and changes in upper extremity muscles strength. The present study involved 80 healthy volunteers and was performed at the Department of Morphology in Riga Stradins University, Riga, Latvia. For measurements we have used the MicroFET2 Hand Held Digital Muscle Tester to determine the strength of the muscles of the hand and arm (M. abductor pollicis longus, M. biceps brachii, M. triceps brachii, M. deltoideus). The results of measurements were then used to analyze the difference in the strength of the muscles innervated by the spinal cord cervical region (C5–C8 nerves) for the same person sitting in the vertical position and sitting with the head flexed maximally. The results of our study support the hypothesis that the changes in the strength of measured muscles are related to the mechanical distension of the spinal cord, which leads to changes in spinal cord's blood supply. The kyphotic position of the cervical spine during head flexion shows that in the spinal cord segments C5 and C7 are formed mechanical distension. Using our statistical study, we can conclude that there is strong relationship in the strength change in some of the observed muscles between vertical position and full flexion of head

Cervical flexion F-waves in the patients with Hirayama diseases

To identify whether there is significant changes between the cervical neutral F-waves and cervical flexion F-waves in the patients with Hirayama disease. This study was performed on 25 normal subjects and 22 male patients with identified Hirayama disease (age: 15 to 44 years; height: 165 to 183 cm; duration: 6 to 240 months) between May 2010 and March 2014. Both cervical flexion F-wave (cervical flexion 45 °, 30 minutes) and conventional F-waves to median nerve stimulation and to ulnar nerve stimulation were performed in all subjects bilaterally. were analyzed by t-test or Fisher exact probability. In the normal subjects, all measurements of the bilateral F-waves didn't have any difference between the cervical flexion position and the cervical neutral position. On the cervical neutral position, the persistence (t = 5.209, P = 0.000), average latencies (t = 4.731, P = 0.022) and minimal latencies (t = 23.843, P = 0.006) of ulnar F-wave on the symptomatic heavier side from the patients with identified Hirayama disease were significantly lower or longer than those from the normal subjects, and the repeat F-waves were found in 3 patients (13.6%). On the symptomatic lighter side, the ulnar F-waves only had lower persistence (t = 22.306, P = 0.001) along with 5 repeat F-waves. Only lower persistence were found in the median F-wave on the both side (higher side t = 23.696, P = 0.000; lighter side t = 23.998, P = 0.000), along with 5 (22.7%) repeat F-waves on the symptomatic heavier side and 6 (27.3%) ones on the symptomatic lighter side. After cervical flexion maintaining 30 minutes, the increased maximal amplitudes (t = -2.552, P = 0.019), average amplitudes (t = -3.322, P = 0.003), duration (t = -3.323, P = 0.00), persistence (t = -2.604, P = 0.017) and frequency of repeat F-waves (9/22, 41%) (P = 0.044) were found on the symptomatic heavier side of ulnar F-wave, and 5 of 10 absent ulnar F-wave on the cervical neutral position were also recover. The median F-wave on the symptomatic heavier side mainly had increased maximal amplitude (t = -3.847, P = 0.001), average amplitudes (t = -2.188, P = 0.040) and persistence (t = -2.421, P = 0.025), and 1 of 6 absent median F-wave on the cervical neutral position were also recover after cervical flexion. The cervical flexion F-waves have significant regular changes compared to the cervical neutral F-waves in patients with Hirayama diseases, especially maximal and average amplitudes of F-waves.

The Quantitative Assessment of Imaging Features for the Study of Hirayama Disease Progression.

Objective. To evaluate the forward shifting of cervical spinal cords in different segments of patients with Hirayama disease to determine whether the disease is self-limiting. Methods. This study was performed on 11 healthy subjects and 64 patients. According to the duration, the patients were divided into 5 groups (≤1 year, 1-2 years, 2-3 years, 3-4 years, and ≥4 years). Cervical magnetic resonance imaging (MRI) of flexion and conventional position was performed. The distances between the posterior edge of the spinal cord and the cervical spinal canal (X), the anterior and posterior wall of the cervical spinal canal (Y), and the anterior-posterior (A) and the transverse diameter (B) of spinal cord cross sections were measured at different cervical spinal segments (C4 to T1). Results. In cervical flexion position, a significant increase in X/Y of C4-5 segments was found in groups 2–5, the C5-6 and C6-7 segments in groups 1–5, and the C7-T1 segments in group 5 (P < 0.05). The degree of the increased X/Y and cervical flexion X/Y of C5-6 segments were different among the 5 groups (P < 0.05), which was likely due to rapid increases in X/Y during the course of Hirayama's disease. Conclusion. The X/Y change progression indicates that Hirayama disease may not be self-limiting.

Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain

BackgroundIndividuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre.MethodsThis study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and internal obliques (IO) of 11 individuals with CLBP and evident PR to 9 healthy controls during the hollowing manoeuvre in seven positions of the upper quarter.ResultsUsing magnitude based inferences it was likely (>75%) that controls had a higher ratio of left IO:RA activation with supine (cervical neutral), asymmetrical tonic neck reflex (ATNR) left and right, right cervical rotation and cervical extension positions. A higher ratio of right IO:RA was detected in the cervical neutral and ATNR left position for the control group. The CLBP group were more likely to show higher activation of the left RA in the cervical neutral, ATNR left and right, right cervical rotation and cervical flexion positions as well as in the cervical neutral and cervical flexion position for the right RA.ConclusionsIndividuals with CLBP and PR manifested altered activation patterns during the hollowing maneuver compared to healthy controls and that altering cervical and upper extremity position can diminish the group differences. Altered cervical and limb positions can change the activation levels of the IO and EO in both groups.