Neutral Head Position Research Articles

Influence of the Craniocervical Posture on Tongue Strength and Endurance.

Tongue strength has an important role in the swallowing process, and previous research has suggested that tongue position, concerning the craniomandibular region, could affect the oral function. This study aimed to evaluate the strength and endurance of three areas of the tongue in three experimentally induced craniocervical postures. A cross-sectional study with a nonprobabilistic sample of 37 participants (mean age: 3.85 ± 3.64years; 20 men, 17 women) was performed. Tongue strength and endurance were assessed using a pressure device entitled Iowa Oral Performance Instrument (IOPI), in three different craniocervical positions: neutral head position (NHP), anterior head translation-or forward head position (FHP), and posterior head translation-or retracted head position (RHP). Measurements taken using the IOPI system showed significant differences in tongue strength for the anterior (p = 0.015) and middle areas of the tongue (p = 0.01). Significant differences were observed in analysis of variance (ANOVA) in the FHP (p = 0.02) and NHP (p = 0.009). The results of tongue endurance measurements showed statistically significant differences for FHP (p = 0.001), NHP (p = 0.00), and RHP (p = 0.007). The craniocervical position influences tongue strength, especially in the anterior and middle tongue areas, concerning the posterior, and, in the anterior and neutral head posture, regarding the retracted position. No differences were found in tongue resistance between the various craniocervical positions, but differences were found in resistance between the different tongue areas.

Two head positions for orotracheal intubation with the trachway videolight intubating stylet with manual in-line stabilization: A randomized controlled trial.

Background:The Trachway Videolight Intubating Stylet is a video-assisted system with a rigid but malleable intubating stylet that facilitates endotracheal intubation. Minimizing cervical spine movement with manual in-line stabilization is essential for patients with cervical spine injuries such as multiple trauma. However, the intubation time of the Trachway Videolight Intubating Stylet and complications associated with intubation in patients with manual in-line stabilization in the neutral-head and head-lift positions remain unclear.Methods:Patients (20–80 years old) who were scheduled to undergo surgery that required general anesthesia with tracheal intubation were randomly allocated to either a neutral-head (n = 62) or a head-lift position (n = 62) group. Manual in-line stabilization was performed to limit cervical spine mobility. We aimed to evaluate orotracheal intubation time and success rate in these 2 positions with the Trachway Videolight Intubating Stylet.Results:Intubation was faster in the head-lift than in the neutral-head position (20 ± 10 and 25 ± 13 seconds, respectively, P = .000); intubation was equally successful in the 2 positions (96.8% vs 96.8%). Responses to intubation did not differ between positions (heart rate, P = .142; visual analog scale scores for throat soreness, P = .54). The only significant predictor of intubation time was the body mass index in the head-lift position group (P = .005).Conclusions:Intubation using the Trachway Videolight Intubating Stylet with manual in-line stabilization is faster in the head-lift position, and therefore preferable. However, if the head-lift position is not suitable, the neutral-head position is a sensible alternative, with comparable intubation success rate, heart rate change, and postoperative throat soreness.

Avaliação de testes à beira leito e proposta de modelo para prever laringoscopia difícil: estudo prospectivo observacional

Background and objectivesThe prediction of difficult laryngoscopy is based on tests that assess anatomic characteristics of face and neck. We aimed to identify the most accurate tests and propose a multivariate predictive model. MethodsThis prospective observational study included 1134 patients. Thyromental Distance (TMD), Sternomental Distance (STMD), Ratio of Height‐to‐Thyromental Distance (R‐H/TMD), Neck Circumference (NC), Ratio of Neck Circumference‐to‐Thyromental Distance (R‐NC/TMD), Hyomental Distance with head in Neutral Position (HMD‐NP) and at Maximal Extension (HMD‐HE), Ratio of Hyomental Distance at Maximal head extension‐to‐hyomental distance in neutral position (R‐HMD), Mallampati Class (MLC), Upper Lip Bite Test (ULBT), Mouth Opening (MO) and Head Extension (HE) were assessed preoperatively. A Cormack‐Lehane Grade ≥ 3 was defined as Difficult Laryngoscopy. Sensitivity, specificity, positive and negative predictive values were assessed for all tests. Multivariate analysis with logistic regression was used to create the predictive models. ResultsA model incorporating MLC, ULBT, HE, HMD‐HE and R‐NC/TMD showed high prognostic accuracy; x2(5)=109.12, p <0.001, AUC=0.86, p <0.001). Its sensitivity, specificity and negative predictive value were 82.3%, 74.8% and 97.4%, respectively. A second model including two measurements not requiring patient's cooperation (R‐NC/TMD and HMD‐HE) exhibited good prognostic performance; x2(2)=63.5, p <0.001, AUC=0.77, p <0.001. Among single tests, HE had the highest sensitivity (78.5%) and negative predictive value (96%). ConclusionsA five‐variable model incorporating MLC, ULBT, HE, HMD‐HE and R‐NC/TMD showed satisfyingly high predictive value for difficult laryngoscopy. A model including R‐NC/TMD and HMD‐HE could be useful in incapable patients. The most accurate single predictor was HE.

Evaluation of bedside tests and proposal of a model for predicting difficult laryngoscopy: an observational prospective study☆

Background and objectivesThe prediction of difficult laryngoscopy is based on tests that assess anatomic characteristics of face and neck. We aimed to identify the most accurate tests and propose a multivariate predictive model. MethodsThis prospective observational study included 1134 patients. Thyromental Distance (TMD), Sternomental Distance (STMD), Ratio of Height-to-Thyromental Distance (R-H/TMD), Neck Circumference (NC), Ratio of Neck Circumference-to-Thyromental Distance (R-NC/TMD), Hyomental Distance with head in Neutral Position (HMD-NP) and at Maximal Extension (HMD-HE), Ratio of Hyomental Distance at Maximal head extension-to-hyomental distance in neutral position (R-HMD), Mallampati Class (MLC), Upper Lip Bite Test (ULBT), Mouth Opening (MO) and Head Extension (HE) were assessed preoperatively. A Cormack-Lehane Grade ≥ 3 was defined as Difficult Laryngoscopy. Sensitivity, specificity, positive and negative predictive values were assessed for all tests. Multivariate analysis with logistic regression was used to create the predictive models. ResultsA model incorporating MLC, ULBT, HE, HMD-HE and R-NC/TMD showed high prognostic accuracy; x2(5) = 109.12, p < 0.001, AUC = 0.86, p < 0.001). Its sensitivity, specificity and negative predictive value were 82.3%, 74.8% and 97.4%, respectively. A second model including two measurements not requiring patient’s cooperation (R-NC/TMD and HMD-HE) exhibited good prognostic performance; x2(2) = 63.5, p < 0.001, AUC = 0.77, p < 0.001. Among single tests, HE had the highest sensitivity (78.5%) and negative predictive value (96%). ConclusionsA five-variable model incorporating MLC, ULBT, HE, HMD-HE and R-NC/TMD showed satisfyingly high predictive value for difficult laryngoscopy. A model including R-NC/TMD and HMD-HE could be useful in incapable patients. The most accurate single predictor was HE.

Kyphosis and 3-year fall risk in community-dwelling older men.

Research suggests an association between hyperkyphosis and falls in community-dwelling older adults, though this has not been investigated within large, population-based studies. This study sought to determine whether two measures of kyphosis prospectively predict fall risk over 3years among older men. Within the Osteoporotic Fractures in Men Study (MrOS), we conducted two 3-year prospective studies of 2346 and 2928 men. The first group had kyphosis measured by the Cobb angle at visit 1, while the second group had kyphosis assessed with the blocks method at visit 3; both groups then self-reported falls tri-annually for 3years. Poisson regression with GEE was used to obtain relative risks (RR) of falls. The fall rates over 3years were 651/1000 person-years among the visit 1 sample (mean age 74 ± 6years) and 839/1000 person-years among the visit 3 sample (mean age 79 ± 5years). In adjusted models of the visit 3 sample, the risk of falls was increased by 12% for each standard deviation increase (1.4 blocks) in the number of blocks required to achieve a neutral head and neck position (RR = 1.12, 95% CI = 1.06, 1.18). The Cobb angle was not associated with falls in the visit 1 sample. Although the Cobb angle did not predict falls in community-dwelling older men over 3years, the blocks method of measuring kyphosis was predictive of falls in this population. This difference could be due to the Cobb angle's focus on thoracic kyphosis, whereas the blocks method may additionally capture abnormal cervical spine curvature.

Abstract TP92: Dynamic Digital Subtraction Angiography With Rotation of Head and Neck May Serve as Critical Imaging Modality and Temporary Use of Cervical Collar in Addition to Anti-Platelet Therapy May Prevent Stroke in Cases of Acute Cervical Vertebral Artery Dissection (CVAD)

Introduction: The AHA/ASA have published a statement on the CVAD in 2014 in which a variety of imaging modalities that are performed with the head in neutral position are discussed and pharmacological and endovascular treatment of CVAD is reviewed. The authors have performed a prospective study of 12 patients with acute spontaneous CVAD from 2012 to 2019 who developed angiographic worsening stenosis or occlusion of the dissected VA associated with rotation of the head and cervical collar was added to the anti-platelet therapy. Methods: From 2012 to 2019, we performed a prospective study of 12 consecutive patients with spontaneous acute CVAD. We reviewed initial and follow-up clinical data and dynamic catheter cerebral angiogram with the patient’s head and neck in the straight neutral position and the head turned to the right and left beyond 60 degrees. Results: A total of 12 patients (Age 41.8 +/- 9.8; M=8, F=4) presented with acute stroke or TIA due to a total of 12 CVAD at the level of V1 (N=1), V2 (N=2), V3 (N=5), V4 (N= 2), V2-3 (N=2) segments diagnosed by cerebral angiogram. Initial mRS and NIHSS scores on admission were 3 +/-0.5 and 1.5 +/- 1.9, respectively. Dynamic cerebral angiogram performed with the patient’s head in neutral position showed average stenosis of 71.6 % +/- 18.9. Symptomatic occlusion or worsening stenosis of the dissected VA was observed on dynamic cerebral angiogram with rotation of the head to the contra-lateral side in 10 of 12 patients (83%). All patients were treated with daily Aspirin and Plavix for at least 3 months and placed on a cervical collar for 1 month. A follow-up dynamic cerebral angiogram at 1.8 +/- 1.4 months showed resolution of rotational occlusion or worsening stenosis of the VA. Clinical follow-up evaluation at 13.1+/- 10.9 months showed mRS score of 0.9+/- 1.0 and NIHSS score of 0.4 +/- 0.7 with no recurrent stroke. Conclusion: Dynamic cerebral angiogram may be critical in diagnosing rotational occlusion or stenosis of the dissected VA in patients with acute CVAD. Traditional imaging of the head and neck in neutral position may fail to diagnose adverse effect of rotation of the head and neck in these patients. Temporary use of cervical collar to prevent rotation of the head in the acute period of CVAD should be considered.

Development and feasibility test of a capacitive belt sensor for noninvasive respiration monitoring in different postures

Abstract The purpose of this study was to develop an easy-wear capacitive belt sensor, examine its performance, and test the feasibility for differentiating posture-dependent respiration changes, consequently for monitoring of variable respiration patterns during real life activities. Seven healthy adult males participated in this study. Respiration (at rest) data were collected simultaneously from capacitive belt sensor and commercial sensor (BIOPAC MP150) for 3 min in each of the 6 different static postures representative of real-life activity postures: supine with neutral head position, standing, sitting, side lying, supine with 45° cervical flexion, and supine with 45° cervical extension. From the collected data, 3 respiratory parameters including total respiration count (RC), peak to peak interval time (PPI), and respiratory rate (RR) were analyzed. Correlation analysis was conducted for all three of the parameters collected by the two sensors. The highest PPI values were found in cervical extension supine posture and the lowest in side lying. RC and PPI patterns were inversely related. The results of RR showed to have exactly the same pattern with RC; the highest rate was during standing and the lowest in cervical extension supine. The RRs detected by our sensor were within the normal range, confirming the performance and feasibility of our sensor. As our sensor was able to detect posture-dependent respiration pattern differences, potential application in sleep apnea monitoring, respiratory disease prevention, and early detection of diagnostic symptoms has been confirmed.

Assessment of head and neck position for optimal ultrasonographic visualisation of the internal jugular vein and its relation to the common carotid artery: A prospective observational study.

Background and Aims:There is a wide variation in the anatomical relationship of the Internal Jugular Vein (IJV) to the Common Carotid Artery (CCA). This makes landmark based techniques of IJV cannulation and head rotation questionable and may lead to accidental arterial puncture. We conducted this study to determine the anatomical relation of the IJV to the CCA using (USG) in patients undergoing IJV cannulation for central venous access, and to analyse the effect of head rotation on this relationship.Material and Methods:A prospective observational study was conducted on 100 patients requiring central venous access, in the operation theatre or the intensive care unit. Anatomical relationship of the IJV to CCA at the level of the cricoid cartilage was analysed by noting the segment position (1-12) around the CCA using a high frequency linear USG probe on patients in neutral head position, on both sides and also with the head rotated to the contra lateral side by 15° and 45°.Results:Antero-lateral segments 1 and 2 were the most common positions (50% on the right and 73% on the left side). Change in segment causing increase in overlap of IJV and CCA with 15° head rotation was seen in 44% subjects on the right and 39% on the left. Statistically, a higher number of subjects showed overlap with 45° rotation (99% on right and 97% on left, P < 0.05).Conclusion:There is a wide variation in anatomical location of the IJV in relation to the CCA as seen by USG. Excessive head rotation causes overlap of IJV over CCA which may cause inadvertent arterial puncture, even under USG guidance. Thus, it is preferable to cannulate the IJV in neutral or near neutral head and neck position.

Lateral head flexion as a noncoplanar solution for ring gantry stereotactic radiosurgery.

Ring gantry radiotherapy devices are often limited to deliver beams in the axial plane, severely limiting beam entrance angles and rendering noncoplanar beam delivery impossible. However, a ring gantry geometry greatly simplifies delivery machines and increases the efficiency of treatment with the potential to decrease the overall costs of radiotherapy. This study explores the use of lateral head flexion in order to increase beam entrance angles and extend the available solid angle space for a ring gantry stereotactic radiosurgery (SRS) application. A 1.5T magnetic resonance imaging scanner was used to scan seven healthy volunteers at three different head positions: a neutral position, a left lateral flexion position and a right lateral flexion position. The lateral flexion scans were co-registered to the neutral head position scan using rigid registration and extracting the rotational transformation. The head pitch, roll, and yaw were computed for each registration to evaluate the natural range of motion for all volunteers. A ring gantry plan geometry was used to generate two sets of single fraction SRS plans (21Gy): one coplanar set for head neutral scans, and a three-arc plan set using the head neutral and lateral head flexion scans. The conformity index (CI), intermediate dose fall-off (R50), low dose spillage (R10), and gradient measure (GM) were used to evaluate both sets of plans. The treatment plans were generated for a ring-gantry linear accelerator (linac) (Varian Halcyon 2.0) as well as radiosurgery linac (Varian Edge) for comparison. The average pitch, yaw, and roll for the lateral head flexion scans were 4.1°±4.7°, 16.9°±3.7°, and 2.5°±4.9° for the right flexion and 4.9°±4.3°, 14.0°±3.7° and 2.8°±5.4° for left flexion. When comparing the head flexion technique with a fully coplanar geometry, the ring gantry plans showed an average improvement in CI of 7.3% (1.46±0.25 vs 1.36±0.28), a decrease of 13% in R50 (5.46±1.14 vs 4.78±1.12), a decrease of 32% in R10 (85.7±20.3 vs 58.2±15.1), and a decrease of 7.8% in GM (0.53±0.05 vs 0.49±0.04). The Edge plans showed an average improvement in CI of 3.0% (1.49±0.26 vs 1.45±0.25), a decrease of 6.8% in R50 (5.19±1.03 vs 4.82±0.83), a decrease of 29% in R10 (84.1±16.3 vs 59.9±12.5), and a decrease of 5.0% in GM (0.50±0.04 vs 0.47±0.03). Lateral head flexion was shown to increase beam entrance angles considerably improving plan conformity and normal tissue sparing in this pilot study of seven sets of plans. Rigid registrations demonstrated each lateral flexion to be analogous to a 15° couch kick. The head flexion technique outlined here was shown to be a feasible solution for SRS treatments being delivered on ring gantry devices.

Ergonomics in Dermatologic Surgery: Lessons Learned Across Related Specialties and Opportunities for Improvement.

As the practice of dermatology becomes increasingly procedurally based, there is a concordant rise in musculoskeletal injury (MSI) risk. Dermatologic surgeons are most susceptible and, although the majority suffer from MSI, few have received any formal ergonomics training. This stems from a lack of awareness of this troubling trend and a paucity of research and education on the ergonomics of dermatologic surgery. To highlight pertinent ergonomics principles and strategies from other specialties that could be translated into dermatology, and to synthesize general recommendations aimed at reducing MSI among dermatologic surgeons. A comprehensive search of the PubMed and Cochrane Reviews databases from 1975 to 2019 was conducted, using a combination of ergonomics-related search terms, generating 6 publications from the dermatology literature and 58 from the fields of dentistry, medicine, and select surgical subspecialties. This multidisciplinary approach yielded multiple interventions that could be applied directly (i.e., adequate lighting, adjustable operating tables, and surgical seat heights) or indirectly pending further investigation into their feasibility (i.e., video displays of the surgical field to allow neutral head and neck postures). Although much can be learned from decades of prior ergonomics research from other specialties, considerations that are unique to dermatology remain and must be addressed with specialty-specific research.

The effect of voluntary head movements on postural kinetics in the standing cat.

BackgroundAlthough the postural instability accompanying bilateral vestibular loss in human and quadrupeds during lateral head movements are well-known, it is still unclear whether or not lateral head turns would indeed activate the postural control system to maintain balance. This study aimed to examine the kinetic parameters in freely standing intact cats during head movements in order to further answer the above question.MethodsSix intact cats were trained to stand, unrestrained on a force plate and perform voluntary head movements to the left and right positions in response to visual cues. Each trial was divided into two phases, quiet standing with the cat’s head maintaining a straight forward and lateral head position after voluntary head movements. Kinetic parameters including peak pressure and contact area under each limb as well as center of pressure (COP) displacements of the whole body were measured.ResultsCompared to the neutral head position, peak pressure and contact area of the left head position were significantly smaller for the left forelimb while greatly larger for the right forelimb. An exact opposite case of peak pressure and contact area in the forelimbs was found between the right and neutral head positions. In addition, the COP displacements altered oppositely to the head movements, and presented a significantly right shift in the left position and a significantly left shift in the right position.ConclusionThese results demonstrate that the lateral displacement of the head in standing intact cats does activate the postural adjustment to maintain balance, which is consistent with the concept that vestibular input can contribute to postural balance during voluntary head turns.

The effect of altered head and tongue posture on upper airway volume based on a validated upper airway analysis-An MRI pilot study.

To determine the influence of altered head or tongue posture on upper airway (UA) volumes using MRI imaging based on a new objective and validated UA evaluation protocol. One supine CBCT and five sagittal MRI scans were obtained from ten subjects in different head and tongue positions: (a) supine neutral head position (NHP) with the tongue in a natural resting position with the tip of the tongue in contact with the lingual aspect of the lower incisors (TRP); (b) head extension with TRP; (c) head flexion with TRP; (d) NHP with the tip of the tongue in contact with the posterior edge of the hard palate (THP); and (e) NHP with the tip of the tongue in contact with the floor of the mouth in contact with the caruncula sublingualis. Based on a validated CBCT UA analysis, the retropalatal, oropharyngeal and the corresponding total volumes were measured from each MRI scan. Wilcoxon signed-rank test was applied to determine the statistically significant difference in mean volume between the baseline head and tongue posture (NHP with TRP) and the other postures. Five females and five males with a mean age of 46.5±13.7years volunteered for this pilot study. UA volumes, particularly the oropharyngeal volume, increased significantly with head extension and NHP with THP and decreased significantly with head flexion. Altered head and tongue posture proved to affect UA volumes, thus representing confounding variables during three-dimensional radiographic image acquisition.

Age-related Changes in Cervical Sagittal Alignment

Retrospective cohort study. To identify age-related changes in cervical sagittal parameters using standard radiographs. Cervical sagittal balance is important for the maintenance of neutral head posture and horizontal gaze. Degenerative changes in the cervical spine that occur with aging may alter cervical sagittal balance, which can lead to chronic neck pain and predispose to various cervical spine pathologies. We performed a retrospective cohort study of 151 patients with lateral cervical spine radiographs taken at our institution between December 2017 and June 2018. Cervical sagittal parameters were measured, including C1 inclination, C2 slope, C2-C7 Cobb angle, cervical sagittal vertical axis (cSVA), cervical tilt, upper and lower C7 slopes, T1 slope, and T1 slope minus cervical lordosis (TS-CL). The association between age and cervical sagittal parameters was assessed using the Pearson correlation coefficient and a linear regression analysis. An analysis of variance (ANOVA) with Tukey adjustments was then performed to identify differences in cervical sagittal parameters among patients aged 18 to 39 years, 40 to 64 years, and >64 years of age. There were positive correlations between age and C2-C7 Cobb angle (r = 0.231, P = 0.004), upper C7 slope (r = 0.280, P < 0.001), lower C7 slope (r = 0.283, P < 0.001), and T1 slope (r = 0.189, P = 0.020). Upper C7 slope (R = 0.079) and lower C7 slope (R = 0.074) had the strongest correlation with age in the linear regression analysis. The ANOVA found significant differences among the age subgroups in terms of C2-C7 Cobb angle (P = 0.002), upper C7 slope (P < 0.001), lower C7 slope (P < 0.001), and T1 slope (P = 0.031). Patients >64 years old had significantly higher C2-C7 Cobb angle, upper C7 slope, lower C7 slope, and T1 slope. Changes in cervical sagittal alignment with age are characterized by increased cervical lordosis and increased thoracic kyphosis. 3.

An equine cadaver study investigating the relationship between cervical flexion, nuchal ligament elongation and pressure at the first and second cervical vertebra

Pressure in the atlanto-axial region due to hyperflexion (‘rollkur’) may influence the development of a nuchal bursa, as adventitious bursae may be caused by pressure. Investigating the pressure between the nuchal ligament and atlas/axis in a flexed position may provide information on the pathogenesis of nuchal bursitis. In this study, ten equine head and neck specimens with one side of the soft tissues over the cervical vertebral spine removed were placed in lateral recumbency on a table in neutral, mildly flexed, and hyperflexed head and neck positions. Angulations of the neck were measured using markers placed on the nuchal ligament and drilled into the skull, vertebrae and withers. In six specimens, the pressure between the nuchal ligament and the atlas and the axis was measured using an inflatable air pouch.Hyperflexion was associated with the highest nuchal ligament length and with the highest pressure values at the site of the nuchal bursa over the atlas (99±24mmHg, more than four times the pressure in the neutral position) and over the axis (77±30mmHg, more than twice the pressure values of the neutral position). Also, over the three head and neck positions, neck flexion angles were highly correlated with pressure values and with nuchal ligament length. This marked increase in pressure at the level of atlas and axis caused by head and neck hyperflexion should be considered during training of horses at risk of, or diagnosed with, nuchal bursitis.

Does Sensorimotor Dysfunction Exist in Asymptomatic Individuals with Forward Head Posture? A Case-Control Study

Background: Forward head posture (FHP), an anterior deviation of the cervical spine, is a common postural malalignment and contributor to neck pain. Impaired muscle activity and continuous excessive loading are commonly seen in individuals with FHP. Centrally, the postural impairment alters incoming sensory information, it's processing in the brain, and consequent output to muscles, causing sensorimotor dysfunction. This study aimed to find whether sensorimotor dysfunction exists in asymptomatic individuals with Forward Head Posture. Our secondary objective was to study whether sensorimotor tests could discriminate between persons with FHP and persons with neutral posture.Case Summary: A case-control study of 31 individuals with FHP and 58 controls with neutral head posture was conducted. We assessed all participants on outcome measures. In addition, a between-group comparison withappropriate statistical analytic tests and AUC plotting of outcome measures was done.Outcome measures: The following outcome measure was used for this study. 1. Cervical joint position error (JPE). 2. Craniocervical flexion test (CCFT). 3. Laterality judgement accuracy. 4. Movement control tests (MCT). 5. Fear Avoidance Behavioral Questionnaire (FABQ)Results: The results of the study indicate that there were significant differences in performance cervical joint position error test (p value&lt;0.05), movement control tests (Total score of 13 MCT &lt;0.05), CCFT activation scores, and performance index scores (p value=0.00) between the two groups. Values of areas under the curve (AUC) indicate that tests for JPE (0.993), CCFT AS (0.841), CCFT PI (0.941), and MCT (0.996) could discriminate well between the two groups. Amongst the 13 movement control tests 3 most discriminative tests are rotation (AUC=0.988), lateral flexion (AUC=0.988) and protraction-retraction (AUC=1.0).Conclusion: We conclude that asymptomatic individuals with forward head posture alter sensorimotor functions. This study gives an insight into the sensorimotor deficits present in asymptomatic individuals with FHP. Emphasis on early correction of FHP should be done to limit these sensorimotor deficits.

Does Sensorimotor Dysfunction Exist in Asymptomatic Individuals with Forward Head Posture? A Case-Control Study

Background: Forward head posture (FHP), an anterior deviation of the cervical spine, is a common postural malalignment and contributor to neck pain. Impaired muscle activity and continuous excessive loading are commonly seen in individuals with FHP. Centrally, the postural impairment alters incoming sensory information, it's processing in the brain, and consequent output to muscles, causing sensorimotor dysfunction. This study aimed to find whether sensorimotor dysfunction exists in asymptomatic individuals with Forward Head Posture. Our secondary objective was to study whether sensorimotor tests could discriminate between persons with FHP and persons with neutral posture.Case Summary: A case-control study of 31 individuals with FHP and 58 controls with neutral head posture was conducted. We assessed all participants on outcome measures. In addition, a between-group comparison withappropriate statistical analytic tests and AUC plotting of outcome measures was done.Outcome measures: The following outcome measure was used for this study. 1. Cervical joint position error (JPE). 2. Craniocervical flexion test (CCFT). 3. Laterality judgement accuracy. 4. Movement control tests (MCT). 5. Fear Avoidance Behavioral Questionnaire (FABQ)Results: The results of the study indicate that there were significant differences in performance cervical joint position error test (p value&lt;0.05), movement control tests (Total score of 13 MCT &lt;0.05), CCFT activation scores, and performance index scores (p value=0.00) between the two groups. Values of areas under the curve (AUC) indicate that tests for JPE (0.993), CCFT AS (0.841), CCFT PI (0.941), and MCT (0.996) could discriminate well between the two groups. Amongst the 13 movement control tests 3 most discriminative tests are rotation (AUC=0.988), lateral flexion (AUC=0.988) and protraction-retraction (AUC=1.0).Conclusion: We conclude that asymptomatic individuals with forward head posture alter sensorimotor functions. This study gives an insight into the sensorimotor deficits present in asymptomatic individuals with FHP. Emphasis on early correction of FHP should be done to limit these sensorimotor deficits.

Effects of rotational head position on the minimum alveolar concentration for tracheal intubation in children under inhalation anesthesia induction during tonsillectomy and adenoidectomy

Objective To investigate the minimum alveolar concentration of sevoflurane for endotracheal intubation in children who underwent tonsillectomy and adenoidectomy under inhalation anesthesia induction without the use of muscle relaxants. Methods A total of sixty-three patients [American Society of Anesthesiologists(ASA) Ⅰ or Ⅱ] undergoing tonsillectomy and adenoidectomy were divided into two groups: a neutral head position group (n=27) and a rotary head position group (n=36) according to the random number table. General anesthesia was induced with 8% sevoflurane. After the loss of the eyelash reflex, the vapourizer was adjusted, so that the end-tidal sevoflurane concentration reached the preset concentration, and maintain for 10 min, followed by endotracheal intubation. The intubation score was assessed using Helbo-Hansen score scale. For each group, the concentration of sevoflurane used for each consecutive patient was increased or decreased using the Dixon′s up-and-down method based on the success or failure to achieve adequate conditions for intubation in the previous patient. The adjacent concentration gradient was 0.5%. Results In the neutral head position group, the minimum alveolar concentration (MAC) of sevoflurane for endotracheal intubation was (4.30±0.44)%, where the median effective dose (ED50) was 4.30%, and the 95% effective dose (ED95) was 4.99%. In the rotary head position group, the MAC of sevoflurane for endotracheal intubation was (3.45±0.54)%, where the ED50 was 3.45%, and the ED95 was 4.62%. Conclusions The head position of rotating 45° was superior to the neutral head position, which can significantly reduce the MAC of sevoflurane for endotracheal intubation in children undergoing tonsillectomy and adenoidectomy. Key words: Children; Sevoflurane; Anesthesia induction; Endotracheal intubation; Minimum alveolar concentration; Tonsillectomy and adenoidectomy

Neuroprotection from acute brain injury in preterm infants.

Infants born at ≤32+6 weeks gestation are at higher risk for intracranial ischemic and hemorrhagic injuries, which often occur in the first 72 hours postbirth. Antenatal strategies to reduce the incidence of acute brain injuries include administering maternal corticosteroids and prompt antibiotic treatment for chorioamnionitis. Perinatal strategies include delivery within a tertiary centre, delayed cord clamping, and preventing hypothermia. Postnatal strategies include empiric treatment with antibiotics when chorioamnionitis is suspected, the cautious use of inotropes, the avoidance of blood PCO2 fluctuation, and neutral head positioning. Clinicians should be aware of the policies and procedures that, especially when combined, can provide neuroprotection for preterm infants.

Differences in palpebral fissure height depending on patient's intraoperative head position

SummaryBackgroundBlepharoptosis operations are performed under local anaesthesia, and it is necessary to determine the location where the levator aponeurosis is fixed to the tarsus by checking opening and closing of the eyelids during surgery. Changes in posture during the operation affect the facial condition in various ways. This study was performed to clarify the differences in palpebral fissure height according to intraoperative head position.MethodsSixty subjects (48 women and 12 men aged 20–76 years) were enrolled in the study. The palpebral fissure height of the dominant eye was measured in the head-neutral position and 30° head-down position.ResultsThe total fissure height in the 30° head-down position was lower than that in the head-neutral position.ConclusionsThe head-down position affects the patient's fissure height and may mislead the operator. Blepharoptosis operation under local anaesthesia should be performed with the patient in the head-neutral position.

Comparison of proprioceptive acuity of the cervical spine in healthy adults and adults with chronic non-specific low back pain: A cross-sectional study.

BackgroundIt has been suggested that patients with chronic non-specific low back pain (CNSLBP) perform poorly in postural tasks when compared to healthy individuals. Despite its importance in posture and alignment of the trunk in relation to the head, neck proprioception has not been examined in patients with low back pain. The purpose of this study was to compare neck proprioception in patients with CNSLBP with healthy individuals.MethodsCervical joint reposition error was measured five times consecutively in the neutral head position, 30° and 60° left and right head rotation. The main outcome measure was the mean cervical joint repositioning error of the head.ResultsForty-six participants with (n = 24, 54 ± 16yrs SD, 14 females) and without (n = 22, 36 ± 13yrs SD, 13 females) CNSLBP were included in the study. Comparison of mean cervical joint repositioning error between patients and healthy controls showed no statistically significant group difference in any of the applied positions. The range of deviation in CNSLBP patients was between 1.57° and 3.27° compared to 1.46° to 2.26° in healthy controls. An overshooting tendency for both groups was found in the neutral head position.ConclusionThe ability to accurately position the head does not seem to be impaired in patients with CNSLBP. This may suggest that sensorimotor control is affected on other levels of the movement system and future research should focus on methods to identify the source of these aberrations.