Postural Changes Research Articles

Justification of the effective sequence of group fitness classes with second mature women (45-55 years old)

This article deals with issues that are aimed at the organization of strength training. First of all, it is necessary to note significant differences between women and men in terms of strength. In women, they are 15-20% lower than in men. Women have a lower tendency to gain muscle mass. This is primarily related to the hormonal background, since the male hormone testosterone is responsible for the growth of muscle mass, and its amount in the body of women is many times smaller than that of men. At the same time, women's ability to display strength indicators of leg muscles is close to men's. Experts in age-related physiology note that at the age of 40-45, reverse processes begin in a woman's body. The main metabolism slows down, the productivity of various organs and systems decreases, the possibility of various pathological processes, chronic diseases, etc. increases. In connection with the decrease in the hormonal background, negative changes are observed in all organs and systems of the body. Blood pressure often rises, a tendency to osteoporosis appears, fat metabolism is disturbed, which often leads to an increase in body fat. There are significant changes in the respiratory system, the vital capacity of the lungs decreases, the mobility of the chest decreases. After 40 years, there is a significant decrease in muscle strength in women. The elasticity of muscles, tendons, and joint performance is lost. At the same time, muscle tone decreases, which leads to negative changes in posture.

Development and evaluation of an air mattress for easy clothes changes for bedridden patients

ABSTRACT Being bed-bound means a loss of mobility and independence. Changing clothes is a challenging task for bedridden patients and caregivers due to the complicated posture changes for the patient and the physical burden on caregivers. To overcome these challenges, a novel approach aiming to minimize caregivers’ physical burden is proposed to assist in changing clothes, including pants, shirts, T-shirts, and A-line dresses, by sequentially controlling the inflation status of each chamber of multichambered air mattresses and performing a unique technique. This study compares patients’ points of movement and physical burden during this activity in the proposed and conventional methods. The experiment for changing pants using the proposed approach shows that no manual posture change of the patient is required. The caregivers only need to put on the pants using a simple movement without applying force against the patient’s body weight. Furthermore, the caregiver only needs to move the patient’s hand when changing shirts, T-shirts, and A-line dresses. The results show that the proposed approach achieves significantly better results than conventional methods. The minimum posture changes during clothes changing prove that the proposed solution can greatly improve patient comfort and reduce caregivers’ burden by 80% on average.

Post-Hatching Development of Posture and Behavior in the Barn Owl (Tyto alba): From a General Behavioral Pattern of Vertebrates to the Typical Owl Behavior.

Hatching captive barn owl chicks underwent four developmental phases. In the first 10 days (phase 1), behavior consisted of lateral movements that gradually changed to forward progression and peaked a few days before and after eye-opening. This behavior resembled a general developmental pattern that characterizes other vertebrates. Chicks also underwent a postural change, from head bent underneath the ventrum to resting on the rear end of the trunk with the head lifted in the air. Then, once their eyes were opened, chicks became more stationary and preoccupied with visual exploration, manifested in lateral head movements and peering episodes (phase 2, until day 20). The latter behavior, which is also typical of mature owls when not on the wing, characterized the chicks' behavior after post-hatching day 20 (phase 3), when their flight and contour feathers grew, along with shedding the down plumage and standing tall. Development culminated in active flight, first observed by days 50-60 (phase 4). Altogether, during post-hatching development, barn owl chicks gradually shifted from egg posture to the adult upright body posture. At the same time, their behavior consisted of speciation from the general developmental pattern to the typical stationary barn owl behavior, and, finally, flight was incorporated.

Improvement of heart rate variability after metabolic bariatric surgery in Korean subjects with obesity.

Cardiovascular autonomic neuropathy (CAN) is a chronic complication of diabetes. As obesity is a major risk factor for CAN, we hypothesized that metabolic bariatric surgery (MBS) could improve CAN indices in Korean patients with obesity. Patients who underwent bariatric surgery between February 2020 and June 2022 were prospectively recruited. CAN was conducted once before surgery and again after surgery, using the Ewing method and heart rate variability (HRV) analysis (standard deviation of the NN interval [SDNN], root mean square of successive RR interval difference [RMSSD], and spectral analysis). A total of 47 patients were included. The mean age was 39.8 ± 8.7 years, 15 (31.9%) were male, and 26 (55.3%) had diabetes. Resting HR before surgery was 81.0 ± 12.3 bpm, which decreased significantly to 68.0 ± 9.3 bpm after surgery (P < 0.001). Changes in HR and BP according to the Valsalva maneuver, postural changes, and handgrip were not significantly different before and after surgery. However, SDNN significantly increased from 25.2 [15.1, 33.5] to 38.0 [25.4, 45.0] ms (P < 0.001), and RMSSD also significantly increased from 17.0 [9.2, 31.8] to 28.2 [15.3, 45.6] ms (P = 0.001). Both low-frequency power (LF) and high-frequency power (HF) increased significantly, and the LF/HF ratio significantly decreased from 2.1 ± 1.6 to 1.3 ± 1.3 (P = 0.010). Loss of weight, fat mass, and lean body mass were independently associated with improving the HRV variables. MBS improved HRV variables, and these changes were mainly associated with postoperative weight loss.

Reverse Engineering to Design an Ergonomic Bio Briquette Packaging Machine

Briquettes are solids that are produced through the process of compression and pressure applicationand if burned will produce a small amount of smoke. Briquette production is carried out using ahammer mill where the raw material for briquettes is charcoal which is then crushed into charcoalgranules. The packaging process is still done manually using a shovel to fill the 50kg sack and thentake it to the sewing machine. The worker's posture when using a shovel has a Rapid Entire BodyAssessment (REBA) score of 12 so it has a high work risk of musculoskeletal disorders (MSDs) andrequires immediate improvement. The working environment at the company produces pollutants,meaning that there is no capture container for the fall of charcoal grains from the hammer mill. Basedon the existing problems, a redesign of the existing machine is needed. The proposed machine wasdesigned using the Reverse Engineering method because the existing condition already uses themachine then the existing machine is decomposed to find out the components and functions of theexisting machine to find alternative concepts. The ergonomic approach uses REBA and LBA todetermine changes in worker posture and the forces acting in the human spine. The DEM approachwas chosen to find out if the charcoal grains dropped from the hammer mill were successfully capturedand to find out the flow of the charcoal grains. The results of the proposed machine design have agood impact on workers in the packaging process.

Changes in Intraocular Pressure While Using Electronic Devices in Sitting and Supine Positions

Objective: This study aimed to compare intraocular pressure (IOP) measurements in sitting and supine positions while exposed to electronic devices. Material and Methods: A total of 26 participants (52 eyes) had their IOP measured by Keeler Pulairs tonometer in sitting and supine positions both before and after using a mobile phone. The IOP was initially measured while sitting, followed by 2 minutes in a supine position. The IOP was then measured again after watching the movie for 30 minutes in each position under daylight conditions. Postural IOP changes due to exposure to electronic devices were measured and compared. Results: The IOP exhibited a statistically significant increase (p-value&lt;0.05) in the supine position compared to the sitting position, both before and after exposure to the electronic device. Following a 30-minute period of exposure, the IOP was significantly reduced by 0.7 mmHg in the sitting position (from 12.7 mmHg to 12.0 mmHg, p-value&lt;0.05). However, there were no significant differences observed in the supine position (13.3 mmHg versus 13.3 mmHg, p-value&gt;0.05). Conclusion: Different postural positions have an effect on IOP, as IOP is higher in the supine position than in the seated position. There was a decline in the IOP after 30 minutes of exposure in the sitting position. However, there are no changes in IOP that occur in the supine position. These findings suggest a potential link between mobile phone usage and postural changes in IOP, which could have implications for ocular health in individuals who frequently use mobile devices.

Fusion Imaging Objectively Demonstrates Improved Pancreas Visualization through Manipulation Techniques: A Prospective Interventional Study.

Objective Abdominal ultrasonography (AUS) is used to screen for abdominal diseases owing to its low cost, safety, and accessibility. However, the detection rate of pancreatic disease using AUS is unsatisfactory. We evaluated the visualization area of the pancreas and the efficacy of manipulation techniques for AUS with fusion imaging. Methods Magnetic resonance imaging (MRI) volume data were obtained from 20 healthy volunteers in supine and right lateral positions. The MRI volume data were transferred to an ultrasound machine equipped with a fusion imaging software program. We evaluated the visualization area of the pancreas before and after postural changes using AUS with fusion imaging and assessed the liquid-filled stomach method using 500 ml of de-aerated water in 10 randomly selected volunteers. Patients This study included 20 healthy volunteers (19 men and 1 woman) with a mean age of 33.0 (21-37.5) years old. Results Fusion imaging revealed that the visualization area of the entire pancreas using AUS was 55%, which significantly improved to 75% with a postural change and 90% when using the liquid-filled stomach method (p=0.043). Gastrointestinal gas is the main obstacle for visualization of the pancreas. Conclusion Fusion imaging objectively demonstrated that manipulation techniques can improve pancreatic visualization.

Application and Research of Intelligent Multi-source Information Fusion Technology in Firefighting Equipment

As modern firefighting environments become increasingly complex, traditional firefighter equipment and operational methods are no longer adequate to address the high-risk challenges of fire rescue operations. Fire scenes are characterized by complex and hazardous environmental factors, with firefighters facing multiple threats such as extreme temperatures, dense smoke, and toxic gases. Therefore, ensuring the safety and efficiency of firefighters is of paramount importance. This study integrates multiple sensor technologies to enable real-time monitoring of firefighters' physiological status, posture changes, and fire scene conditions. The system incorporates ErgoLAB wireless ECG and PPG sensors, the BWT61CL posture sensor, and the MAG14mini infrared camera, which are capable of simultaneously capturing key physiological data and heat distribution in the fire scene. To ensure data accuracy and real-time performance, the study employs efficient signal preprocessing techniques, including noise reduction, baseline correction, and time synchronization. In addition, wireless transmission technology and multimodal data fusion algorithms are utilized to comprehensively analyze the firefighters' status and fire scene conditions. This approach significantly enhances the precision of firefighter safety monitoring and operational efficiency, demonstrating substantial innovation and practical value.

The impact of gravity on perceived object height

Altering posture relative to the direction of gravity, or exposure to microgravity has been shown to affect many aspects of perception, including size perception. Our aims in this study were to investigate whether changes in posture and long-term exposure to microgravity bias the visual perception of object height and to test whether any such biases are accompanied by changes in precision. We also explored the possibility of sex/gender differences. Two cohorts of participants (12 astronauts and 20 controls, 50% women) varied the size of a virtual square in a simulated corridor until it was perceived to match a reference stick held in their hands. Astronauts performed the task before, twice during, and twice after an extended stay onboard the International Space Station. On Earth, they performed the task of sitting upright and lying supine. Earth-bound controls also completed the task five times with test sessions spaced similarly to the astronauts; to simulate the microgravity sessions on the ISS they lay supine. In contrast to earlier studies, we found no immediate effect of microgravity exposure on perceived object height. However, astronauts robustly underestimated the height of the square relative to the haptic reference and these estimates were significantly smaller 60 days or more after their return to Earth. No differences were found in the precision of the astronauts’ judgments. Controls underestimated the height of the square when supine relative to sitting in their first test session (simulating Pre-Flight) but not in later sessions. While these results are largely inconsistent with previous results in the literature, a posture-dependent effect of simulated eye height might provide a unifying explanation. We were unable to make any firm statements related to sex/gender differences. We conclude that no countermeasures are required to mitigate the acute effects of microgravity exposure on object height perception. However, space travelers should be warned about late-emerging and potentially long-lasting changes in this perceptual skill.

Enhancing postural stability in musculoskeletal quadrupedal locomotion through tension feedback for CPG-based controller.

A central pattern generator (CPG)-based controller enhances the adaptability of quadrupedal locomotion, for example, by controlling the trunk posture. The conventional CPG-based controllers with attitude control often utilized the posture angle as feedback information. However, if the robot's body is as soft as a musculoskeletal structure, it can measure the over-tilting of the trunk based on proprioceptive information of the muscles. In general, proprioceptive information such as muscle tension changes more rapidly than posture angle information. Therefore, a feedback loop based on proprioceptive information has great potential to respond to sudden disturbances that occur during locomotion over uneven terrain. In this research, we proposed a CPG-based controller utilizing the tension of soft pneumatic artificial muscles (PAMs). Musculoskeletal quadruped robots driven by PAMs are so soft, which prevents over-extension of the leg and over-tilting of the trunk to some extent. In addition, tension, one of the proprioceptive information of PAMs, exhibits high sensitivity to changes in trunk posture because the soft body's motion easily changes due to over-titing of the trunk. To validate the efficacy of the proposed controller, we conducted numerical simulations with a simple quadruped model and experiments with a musculoskeletal quadruped robot. As a result, the tension feedback was effective for posture stabilization when the robot's locomotion was subjected to disturbances. Moreover, the tension feedback was effective in improving the running velocity over uneven terrain. These results will enhance the locomotion capability of musculoskeletal quadruped robots, advancing their practical application.&#xD.

First evolutionary insights into the human otolithic system

The human otolithic system (utricle and saccule), housed within the bony vestibule of the inner ear, establishes our sense of balance in conjunction with the semicircular canals. Yet, while the morphological evolution of the semicircular canals is actively explored, comparative morphological analyses of the otolithic system are lacking. This is regrettable because functional links with head orientation suggest the otolithic system could be used to track postural change throughout human evolution and across primates more broadly. In this context, we present the first analysis of the evolution of the human otolithic system within an anthropoid primate setting. Using the vestibule as a morphological proxy for the utricle and saccule, we compare humans to 13 other extant anthropoid species, and use phylogenetically-informed methods to find correlations with body size, endocranial flexion, and head-neck posture. Our results, obtained through micro-CT of 136 inner ears, reveal two major evolutionary transitions in hominoids, leading to distinctive vestibular morphology in humans, characterized by otolithic morphology resembling squirrel monkeys (possibly due to reversal), with a pronounced supraovalic fossa. Finally, we find a positional signal embedded in the anthropoid bony vestibule, providing the foundation to further explore the evolution of human head-neck posture using inner ear morphology.

The Influence of Kinesiology Tape on Posture and Breathing Mechanics in Healthy Individuals: A Randomized Trial

Background and Purpose: Kinesiology tape (KT) has been used clinically to improve posture, mobility, and muscle strength. Limited research has investigated the effect of KT on respiratory function. The purpose of this study was to explore the effects of KT on posture and breathing in healthy individuals. Methods: Ninety-two adult participants were randomly assigned to a KT, sham tape (ST), or control group. Data collection occurred over 2 sessions. Baseline measurements included chest wall expansion (CWE) at the sternal angle (SA) and xiphoid process (Xi), maximal inspiratory pressure (MIP), and tragus (TWD) and acromion (AWD) to wall distances. Next, KT or ST was applied to the upper back and neck, or no tape was applied based on group assignment. Measurements were then repeated. Participants returned for a final round of measurements 48 hours later. Mixed-measures ANOVAs were used to determine the influence of tape at baseline (T0), immediately post-taping (T1), and 48 hours post-taping (T2). Post hoc analyses used the Tukey method. Results: Analysis showed significant differences between T0 and T1 (P = .004) and between T1 and T2 (P = .004) for AWD on the left. CWE-Xi data showed within group differences T0-T2 (P = .004) and T1-T2 (P = .004). MIP data showed within group differences between T0 and T1 (P = .001), T0 and T2 (P &lt; .001), and T1 and T2 (P &lt; .001). Discussion: KT had a limited and inconsistent impact on posture where there was a decrease in AWD on the left from T0 to T1 and then an increase from T1 to T2. No other changes in posture were found. Taping did not affect CWE at the SA. There was an evident training effect for CWE-Xi and MIP, where all groups saw increases over time. Conclusion: This method of KT application is not supported as an intervention for influencing posture and enhancing inspiratory breathing mechanics in healthy adults. Further investigation of KT in other populations is needed.

The effect of physiotherapy intervention on functional outcomes among COVID-19 patients: Clinical experimental study.

COVID-19 is a highly contagious virus that causes pneumonia, which quickly progresses to acute respiratory distress. In the case of COVID-19, physiotherapy is critical in non-invasive support management, postural changes, chest physiotherapy (CPT), and bed mobility. This study aims to look into the effects of physiotherapy intervention on functional outcome levels in COVID-19 patients in the acute stage. A total of 60 severe COVID-19 patients (54 males and 6 females) with a mean age of 50years were studied. The intervention group (n=30) had two daily physiotherapy sessions that included positioning, CPT, cardio exercises, breathing exercises, and early mobility, whereas the control group (n=30) received only standard medical care. Patients were tested twice at the baseline and discharge using peripheral oxygen saturation, respiratory rate (RR) test, dyspnea rate, two-min walk test, and spirometer scores, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). The two groups improved significantly between the baseline and discharge ratings. The intervention group, on the other hand, significantly improved all outcome indicators at discharge (p-value=0.00). This study found that physiotherapy management improved oxygen saturation, RR, dyspnea, and lung function tests in COVID-19 patients except in FVC (p-value=0.402) and FEV1(p-value=0.114). Physiotherapist interventions with COVID-19 patients increase respiratory function and treatment time.

Postural Change Assists Surgical Maneuverability During Endoscopic Transsphenoidal Surgery for Pituitary Macroadenoma

In endoscopic transsphenoidal surgery for pituitary adenoma with suprasellar extension, the prolapse of the stretched floppy diaphragma sellae can obstruct the surgical corridor, posing challenges during pituitary surgery. We have introduced a simple postural change technique to mitigate this issue and are sharing our clinical experience. Pituitary surgery is performed on an operating bed where the patient's position can be adjusted. During transsphenoidal pituitary surgery, raising the patient's head to a Fowler's position causes the diaphragma sellae to move upward, while lowering the head to a supine position causes it to descend. This simple adjustment minimizes hindrance from the floppy diaphragm sellae during surgery. We illustrate this technique in pituitary surgery, where diaphragm sellae relocation is necessary. A simple postural change technique effectively manages prolapsed floppy diaphragma sellae, enhancing visualization and surgical accessibility during endoscopic transsphenoidal pituitary surgery.

Unveiling the dynamics of intraoperative contamination in total hip arthroplasty: the discrepancy between particulate and microbial contamination in surgical site infection risk

BackgroundSurgical site infection (SSI) is a major problem following total hip arthroplasty (THA). This study investigated the impact of a standard intraoperative routine where the surgical team wears full-body exhaust suits (space suits) within a laminar airflow (LAF)-ventilated operating room (OR) on environmental contamination. Our primary objective was to identify potential modifiable intraoperative factors that could be better controlled to minimize SSI risk.MethodsWe implemented an approach involving simultaneous and continuous air sampling throughout actual primary cementless THA procedures. This method concurrently monitored both airborne particle and microbial contamination levels from the time the patient entered the OR for surgery until extubation.ResultsAirborne particulate and microbial contamination significantly increased during the first and second patient repositionings (postural changes) when the surgical team was not wearing space suits. However, their concentration exhibited inconsistent changes during the core surgical procedures, between incision and suturing, when the surgeons wore space suits. The microbial biosensor detected zero median microbes from draping to suturing. In contrast, the particle counter indicated a significant level of airborne particles during head resection and cup press-fitting, suggesting these procedures might generate more non-viable particles.ConclusionsThis study identified a significant portion of airborne particles during the core surgical procedures as non-viable, suggesting that monitoring solely for particle counts might not suffice to estimate SSI risk. Our findings strongly support the use of space suits for surgeons to minimize intraoperative microbial contamination within LAF-ventilated ORs. Therefore, minimizing unnecessary traffic and movement of unsterile personnel is crucial. Additionally, since our data suggest increased contamination during patient repositioning, effectively controlling contamination during the first postural change plays a key role in maintaining low microbial contamination levels throughout the surgery. The use of sterile gowns during this initial maneuver might further reduce SSIs. Further research is warranted to investigate the impact of sterile attire on SSIs.

Evaluation of craniocervical posture after myofascial pain treatment in adults with bruxism: A randomized clinical trial

BackgroundDespite numerous clinical studies on bruxism management, critical evaluation parameters, including the impact of bruxism pain on quality of life and secondary issues like changes in craniocervical posture, are often disregarded. Research questionEvaluate the effect of two treatments on the craniocervical posture of adult patients with myofascial pain. MethodsThis parallel randomized clinical trial included 60 patients with myofascial pain due to probable bruxism that fulfilled the study requirements. A computer-generated random sequence was used to allocate treatments: botulinum toxin-A or occlusal appliance. Follow-up time was 3 and 6 months. Kyphosis angle (α) and head posture measurement by cervical radiograph were assessed using two-way repeated measures ANOVA (alpha = 0.05). ResultsSixty patients were randomized (mean age 30 ± 7.6) and 6 were excluded from the analysis (did not attend follow-up). No statistically significant difference was observed for the head posture measure (p = 0.98) and kyphosis angle (p = 0.74). Mild pain was reported by one patient after botulinum toxin-A application. SignificanceResults indicate that craniofacial posture does not seem to be influenced by the treatment of pain in bruxers. If a better posture is desired, this should probably be targeted with other therapies. Trial registrationClinical Trials NCT03456154.

Chronic Wireless Communication Between Dual-Chamber Leadless Pacemaker Devices

BackgroundAveir™ DR (Abbott) is a dual-chamber leadless pacemaker (LP) system with distinct atrial and ventricular LPs (ALP, VLP) that communicate wirelessly to deliver atrioventricular synchronous pacing. Success rates of these implant-to-implant (i2i™) transmissions have not been systematically evaluated. ObjectiveTo evaluate chronic i2i success rates in a clinical setting. MethodsPatients meeting standard dual-chamber pacing indications were enrolled and implanted with dual-chamber LP systems as part of a prospective, international clinical trial (“Aveir DR i2i Study”). The percent of successful i2i transmissions from ALP-to-VLP (A-to-V) and VLP-to-ALP (V-to-A) were interrogated from LPs in de novo patients using the device programmer at implant, discharge, and at 1-, 3-, and 6-months post-implant (1M, 3M, 6M). Results399 patients completed device implant and i2i diagnostic interrogation (62% male; age 69 years; 65% sinus node dysfunction, 32% AV block). Median A-to-V and V-to-A i2i success rates exceeded 90% of beats at all time-points from implant to 6M. The minority of patients with A-to-V or V-to-A i2i success in <70% of beats at implant (A-to-V: 19% of patients, V-to-A: 31% of patients) showed roughly 40% improvement by 1M, with this minority dropping to roughly 5% of patients by 6M. Improvement in i2i communication success may be attributed to reprogramming of i2i setting levels, natural changes in dominant posture, and device stabilization. ConclusionWireless implant-to-implant communication in the new dual-chamber leadless pacemaker system demonstrated successful transmissions in >90% of beats throughout the 6-month evaluation period. Communication success improved significantly over time post-implant for specific subgroups.

Postural Control Changes When Performing Explosive Ordnance Disposal (eod) Operational Tasks With Eod Personal Protection Equipment (PPE): Bending Over At The Waist

Postural Control Changes When Performing Explosive Ordnance Disposal (eod) Operational Tasks With Eod Personal Protection Equipment (PPE): Bending Over At The Waist

Self‐Propelled Morphing Matter for Small‐Scale Swimming Soft Robots

AbstractAquatic insects have developed versatile locomotion mechanisms that have served as a source of inspiration for decades in the development of small‐scale swimming robots. However, despite recent advances in the field, efficient, untethered, and integrated powering, actuation, and control of small‐scale robots remains a challenge due to the out‐of‐equilibrium and dissipative nature of the driving physical and chemical phenomena. Here, we have designed small‐scale, bioinspired aquatic locomotors with programmable deterministic trajectories that integrate self‐propelled chemical motors and photoresponsive shape‐morphing structures. A Marangoni motor system is developed integrating structural protein networks that self‐regulate the release of chemical fuel with photochemical liquid crystal network (LCN) actuators that change their shape and deform in and out of the surface of water. While the diffusion of fuel from the motor system regulates the propulsion, the dissipative photochemical deformation of LCNs provides locomotors with control over the directionality of motion at the air‐water interface. This approach gives access to five different but interchangeable modes of locomotion within a single swimming robot via morphing of the soft structure. The proposed design, which mimics the mechanisms of surface gliding and posture change of semiaquatic insects such as water treaders, offers solutions for autonomous swimming soft robots via untethered and orthogonal power and control.

New results in stereopsis and Listing's law.

Human eyes' optical components are misaligned. This study presents comprehensive geometric constructions in the binocular system, with the eye model incorporating the fovea that is displaced from the posterior pole and the lens that is tilted away from the eye's optical axis. It extends their previously considered horizontal misalignment with the vertical components. When the eyes' binocular posture changes, 3D spatial coordinates of the retinal disparity (iso-disparity curves), the subjective vertical horopter, and the eye's torsional orientation transformations are visualized in GeoGebra's simulations. The consequences and functional roles of vertical misalignment of the eye's optical components are explained in the following findings: (1) The classic Helmholtz theory, which states that the subjective vertical retinal meridian inclination to the retinal horizon explains the backward tilt of the perceived vertical horopter, is less relevant when the eye's optical components are misaligned. Instead, the lens vertical tilt provides the retinal vertical criterion that explains the experimentally measured vertical horopter inclination. (2) Listing's law, which originally restricts single-eye torsional positions and has imprecise binocular extensions, is formulated for binocular fixations using Euler's rotation theorem. It, however, replaces Listing's plane, which is defined for eyes looking at infinity, with the eyes muscles' natural tonus resting position corresponding to the abathic distance fixation of empirical straight frontal horopter. This new meaning of Listing's plane provides neurophysiological significance that has remained elusive.