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This study aimed to measure trunk rotation angle representations from images using a single camera combined with a posture mirror and to examine its reliability and validity. We applied a trunk rotation angle model using a tripod and markers simulating trunk rotation. We compared two methods of trunk rotation angle measurement: the conventional method from the superior aspect using a manual goniometer and a novel measurement method using images from a digital camera and a posture mirror. Measurement error was calculated as the average absolute error between the angle measured by the goniometer and that calculated from the camera and mirror image. The intraclass correlation coefficient (ICC 1, 1) and ICC (2, 1) were calculated as the intra-rater reliability and agreement between the measurement angles of the two methods, respectively. Systematic errors of the angles measured by the two methods were examined by a Bland‒Altman analysis. The mean (SD) of the mean absolute error was 1.17° (0.71°). ICC (1, 1) was 0.978, and ICC (2, 1) was 0.991. The Bland‒Altman analysis showed no systematic errors. The results suggest the validity and accuracy of our novel method to measure the angle of trunk rotation, which does not require high-cost equipment or a special environment.

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BACKGROUND: Cardiac rotational parameters in primary symptomatic left ventricular noncompaction (LVNC) with preserved left ventricular ejection fraction (LVEF) are not well understood. We aimed to analyze cardiac rotation measured with cardiac magnetic resonance feature-tracking (CMR-FT) and speckle-tracking echocardiography (Echo-ST) in LVNC morphology subjects with preserved LVEF and different genotypes and healthy controls. METHODS: Our retrospective study included 54 LVNC subjects with preserved LVEF and 54 control individuals. We evaluated functional and rotational parameters with CMR in the total study population and with echocardiography in 39 LVNC and 40 C individuals. All LVNC subjects were genotyped with a 174-gene next-generation sequencing panel and grouped into the subgroups: benign (B), variant of uncertain significance (VUS), and pathogenic (P). RESULTS: In comparison with controls, LVNC subjects had reduced apical rotational degree (p = 0.004) and one-third had negative apical rotation. While the degree of apical rotation was comparable between the three genetic subgroups, they differed significantly in the direction of apical rotation (p<0.001). In contrast to control and B groups, all four studied cardiac rotational patterns were identified in the P and VUS subgroups, namely normal rotation, positive and negative rigid body rotation, and reverse rotation. When the CMR-FT and Echo-ST methods were compared, the direction and pattern of cardiac rotation had moderate to good association (p<0.001) whereas the rotational degrees showed no reasonable correlation or agreement. CONCLUSION: While measuring cardiac rotation using both CMR-FT and Echo-ST methods, subclinical mechanical differences were identified in subjects with LVNC phenotype and preserved LVEF, especially in cases with genetic involvement.

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Currently, the relationship between axial rotation of the vertebrae and bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) remains controversial. The aim of this study is to quantitatively assess the effect of vertebral rotation on volumetric bone mineral density (v-BMD) and areal bone mineral density (a-BMD), further to propose the corrected strategies. To achieve this, a phantom, which was rotated from 0° to 25° in 5° increments, was utilized. Bone mineral content (BMC), a-BMD, v-BMD, and projected area (p-AREA) were measured. The Kruskal-Wallis non-parametric test or one-way ANOVA was used to examine the differences in variables between the different groups. The Pearson and Spearman correlation was used to test the relationships between quantitative parameters and rotated angles. Linear regression analysis was used to evaluate the relationship between angles and quantitative parameters. The findings indicate that, as the angle increased, a-BMD and v-BMD decreased (P < 0.001) , and the p-AREA increased (P < 0.001), but the BMC stays constant. The rotated angle was negative correlated (r = - 0.925, P < 0.001) with a-BMD and v-BMD (r = - 0.880, P < 0.001), positive (r = 0.930, P = < 0.001) correlated with p-AREA. The linear regression analysis showed that a-BMD = 0.808-0.01 × Angle and v-BMD = 151.808-1.588 × Angle. This study showed that, axial rotation might lead to a lower measured for a-BMD and v-BMD, it should be modified. This gives clinicians some insights into how to deal with osteoporosis in scoliosis patients. It's essential for clinicians to incorporate these findings into their diagnostic processes to prevent potential misdiagnosis and over-treatment of osteoporosis.

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As a critical sensor protein, NLRP3 detects cellular perturbation caused by diverse exogenous and endogenous stimuli. NLRP3 activation requires domain rotation within the NEK7-bound NLRP3 monomer and assembly. However, a detailed molecular mechanism for NLRP3 assembly and activation remains elusive, particularly in terms of dynamics and energetics. In this work, all-atom molecular dynamics (MD) simulations are executed to describe large-amplitude closed-to-open conformational transitions along the rotational pathway. From the MD trajectories, the computed potential of mean force (PMF) shows that NLRP3 activation through monomeric domain rotation is an uphill process, during which the active conformation of the NLRP3-NEK7 monomer cannot be stabilized. Further binding free-energy calculations for two neighboring NLRP3-NEK7 subunits in a disc assembly with the C10 symmetry reveal that the protein self-assembly starts approximately at the 86.5° position on the rotary pathway, along which the NLRP3 activation becomes a downhill process to the active state at 90.5°. The active NLRP3-NEK7 monomeric conformation in the disc assembly is stabilized because of the interactions between the neighboring subunits, involving mainly FISNA loop 1 in one subunit and a "crocodile-clip" structure formed by the NBD helix-loop-strand motif (residues 351-373) and the WHD ß-hairpin loop (residues 501-521) in the other. Our simulations also demonstrate that NEK7 plays an important role in the NLRP3 cage dissociation in the centrosome, which is consistent with biological experiments. The computational results provide kinetic, energetic, and structural insights into the molecular mechanisms of the activation of NLRP3 and the NEK7-driven dissociation of inactive NLRP3 cages. The activation mechanism of NLRP3 proposed in this work is significantly different from those of previous structural studies.

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BACKGROUND: Individual maximum joint and segment angular velocities have shown positive associations with throwing arm kinetics and ball velocity in baseball pitchers. PURPOSE: To observe how cumulative maximum joint and segment angular velocities, irrespective of sequence, affect ball velocity and throwing arm kinetics in high school pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: High school (n = 55) pitchers threw 8 to 12 fastball pitches while being evaluated with 3-dimensional motion capture (480 Hz). Maximum joint and segment angular velocities (lead knee extension, pelvis rotation, trunk rotation, shoulder internal rotation, and forearm pronation) were calculated for each pitcher. Pitchers were classified as overall fast, overall slow, or high velocity for each joint or segment velocity subcategory, or as population, with any pitcher eligible to be included in multiple subcategories. Kinematic and kinetic parameters were compared among the various subgroups using t tests with post hoc regressions and multivariable regression models created to predict throwing arm kinetics and ball velocity, respectively. RESULTS: The lead knee extension and pelvis rotation velocity subgroups achieved significantly higher normalized elbow varus torque (P = .016) and elbow flexion torque (P = .018) compared with population, with equivalent ball velocity (P = .118). For every 1-SD increase in maximum pelvis rotation velocity (87 deg/s), the normalized elbow distractive force increased by 4.7% body weight (BW) (B = 0.054; ß = 0.290; P = .013). The overall fast group was older (mean ± standard deviation, 16.9 ± 1.4 vs 15.4 ± 0.9 years; P = .007), had 8.9-mph faster ball velocity (32.7 ± 3.1 vs 28.7 ± 2.3 m/s; P = .002), and had significantly higher shoulder internal rotation torque (63.1 ± 17.4 vs 43.6 ± 12.0 Nm; P = .005), elbow varus torque (61.8 ± 16.4 vs 41.6 ± 11.4 Nm; P = .002), and elbow flexion torque (46.4 ± 12.0 vs 29.5 ± 6.8 Nm; P < .001) compared with the overall slow group. A multiregression model for ball velocity based on maximum joint and segment angular velocities and anthropometrics predicted 53.0% of variance. CONCLUSION: High school pitchers with higher maximum joint and segment velocities, irrespective of sequence, demonstrated older age and faster ball velocity at the cost of increased throwing shoulder and elbow kinetics. CLINICAL RELEVANCE: Pitchers and coaching staff should consider this trade-off between faster ball velocity and increasing throwing arm kinetics, an established risk factor for elbow injury.

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Cells depend on a continuous supply of adenosine triphosphate (ATP), the universal energy currency. In mitochondria, ATP is produced by a series of redox reactions, whereby an electrochemical gradient is established across the inner mitochondrial membrane. The ATP synthase harnesses the energy of the gradient to generate ATP from adenosine diphosphate (ADP) and inorganic phosphate. We determined the structure of ATP synthase within mitochondria of the unicellular flagellate Polytomella by electron cryo-tomography and subtomogram averaging at up to 4.2-angstrom resolution, revealing six rotary positions of the central stalk, subclassified into 21 substates of the F1 head. The Polytomella ATP synthase forms helical arrays with multiple adjacent rows defining the cristae ridges. The structure of ATP synthase under native operating conditions in the presence of a membrane potential represents a pivotal step toward the analysis of membrane protein complexes in situ.

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Purpose: Previous studies have proven that modifications in the natural walking technique alter muscle activation and energy consumption. This research aimed to determine the differences in muscle activation, energy consumption, kinematic characteristics, perceived muscular exertion and perceived cardio-respiratory fatigue between natural and modified walking techniques with altered pelvic height and rotation. Methods: Nine physically active, non-injured males walked on a treadmill. Modified walking techniques assumed maintenance of constant pelvic height and application of maximal pelvic rotation. Walking speed was subtransit - 0.4 km/h less than the transit. Sampled variables were: average normalized maximal activation during contact and swing phase relativized to maximal voluntary activation, average submaximal oxygen consumption relativized to body mass and subtransit speed, average step length and frequency, rating of perceived muscular exertion and perceived cardio-respiratory fatigue. Muscle activation, energy consumption and kinematic characteristics were assessed throughout each walking session. Perceived muscular exertion and perceived cardio-respiratory fatigue were evaluated post-session. Electromyographic activity was assessed for rectus femoris, gluteus maximus, vastus medialis, biceps femoris, tibialis anterior and gastrocnemius lateralis. Results: The most significant changes in muscle activation were observed during the contact phase. A decrease in pelvic height increased muscle activation of rectus femoris, vastus medialis and gastrocnemius lateralis. An increase in pelvic rotation increased muscle activation of all monitored muscles except for gluteus maximus. Both modifications increased energy consumption, perceived muscular exertion and perceived cardio-respiratory fatigue, and altered kinematic characteristics. Conclusions: Modifications in pelvic height and rotation at the same walking speed alter muscle activation, energy consumption, kinematic characteristics, perceived exertion and fatigue.

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Recent biomechanical evidence suggests that shoulder impingement syndrome (SIS) is closely linked with altered core-shoulder kinetic chain, resulting pain, altered external shoulder muscle activation, and external muscle weakness. We aimed to compare the effects of conventional isolated shoulder exercise (ISE) and core-shoulder chain exercises (CCE) during isokinetic shoulder rotation in baseball pitchers with SIS. Forty male college baseball pitchers with SIS were randomly allocated to ISE and CCE groups and they performed the exercises 3 times a week for 6 weeks. The standardised numerical pain rating scale (NPRS), shoulder pain and disability index (SPADI), electromyography (EMG) amplitude, and concentric (CON) and eccentric (ECC) torques were measured. Substantial improvements in NPRS and SPADI scores were observed after CCE compared to ISE (p ≤ 0.046). Internal oblique/transversus abdominis, rectus abdominis, external oblique, serratus anterior, and infraspinatus muscle activation were significantly higher after CCE than ISE (p ≤ 0.033). CON and ECC torques were higher after CCE than ISE (p ≤ 0.002). The present findings demonstrated superior therapeutic effects of CCE in improving pain, disability level, shoulder muscle activation, and torque (muscle strength) in baseball pitchers with SIS compared to the conventional ISE, highlighting the importance of the chain exercise concept.

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Accurately estimating whole-body angular momentum (WBAM) during daily activities may benefit from choosing a locally-defined reference frame aligned with anatomical axes, particularly during activities involving body turns. Local reference frames, potentially defined by pelvis heading angles, horizontal center of mass velocity (vCoM), or average angular velocity ( Aω ), can be utilized. To minimize the impact of inherent mediolateral oscillations of these frames, such as those caused by pelvis or vCoM rotation in the transverse plane, a low-pass filter is recommended. This study investigates how differences among global, local reference frames pre- and post-filtering affect WBAM component distribution across anatomical axes during straight-line walking and various turning tasks, which is lacking in the literature. Results highlighted significant effects of reference frame choice on WBAM distribution in the anteroposterior (AP) and mediolateral (ML) axes in all tasks. Specifically, expressing WBAM in the vCoM-oriented local reference frame yielded significantly lower (or higher) WBAM in the AP (or ML) axes compared to pelvis-oriented and Aω -oriented frames. However, these significant differences disappeared after employing a low-pass filter to local reference frames. Therefore, employing low-pass filtered local reference frames is crucial to enhance their applicability in both straight-line and turning tasks, ensuring more precise WBAM estimates. In applications that require expressing anatomical axes-dependent biomechanical parameters in a local reference frame, pelvis- and vCoM-oriented frames are more practical compared to the A ω -oriented frame, as they can be determined by a reduced optical marker set or inertial sensors in future applications when the whole-body kinematics is not available.

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This article introduces an innovative approach for creating a circular polarization (CP) antenna-based rotation-insensitive implantable wireless power transfer (WPT) system for medical devices. The system is constructed to work in the industrial, scientific, and medical (ISM) frequency band of 902-928 MHz. Initially, a flexible, wide-band, and bio-compatible open-ended CP slot antenna is designed within a single-layer human skin tissue model to serve as the receiving (Rx) element. To form the implantable WPT link, a circular patch antenna is also constructed in the free-space to use as a transmitting (Tx) source. Further, a new metamaterial-polarization converter (MTM-PC) structure is developed and incorporated into the proposed system to enhance the power transfer efficiency (PTE). Furthermore, the rotational phenomenon of the Rx implant has been studied to show how the rotation affects the system's performance. Moreover, a numerical analysis of the specific absorption rate (SAR) is conducted to confirm compliance with safety regulations and prioritize human safety from electromagnetic exposure. Finally, to validate the introduced concept, prototypes of the different elements of the proposed WPT system were fabricated and tested using skin-mimicking gel and porcine tissue. The measured results confirm the feasibility of the introduced approach, exhibiting improved efficiency due to use of the MTM-PC. The amplitude of the transmission coefficient ( | S 21 | ) has improved by 6.94 dB in the simulation, whereas the enhancement of 7.04 dB and 6.76 dB is obtained from the experimental study due to the integration of MTM-PC. As a result, the PTE of the proposed MTM-PC integrated implantable WPT system is increased significantly compared to the system without MTM-PC.

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PURPOSE: To explore the use of autologous astigmatic lenticule reshaping and rotation surgery to correct high astigmatism in conjunction with excimer laser technology to correct residual refractive error. METHODS: Six patients with high astigmatism (8 eyes, all with astigmatism from -5.50 to -11.00 diopters [D]) seeking refractive error correction were enrolled. The following methods were used to correct refractive errors that could not be corrected by a single conventional surgery: (1) cutting of a customized lens using FLEx technology, (2) lifting of the corneal flap and reshaping the autologous astigmatic lenticule in situ using an excimer laser, and (3) rotation of the autologous astigmatic lenticule by 90°. Uncorrected distance visual acuity, subjective refraction, corneal topography, and anterior segment optical coherence tomography were performed preoperatively and postoperatively. RESULTS: The efficacy and safety indices at 6 months postoperatively were 0.93 ± 0.18 and 1.06 ± 0.11, respectively, the spherical equivalent remained stable and close to emmetropia (-0.13 ± 0.70 D) from 1 to 6 months postoperatively, postoperative astigmatism was generally mildly undercorrected (-1.22 ± 0.43 D), and the difference in corneal curvatures at 2 mm from the apex of the cornea was significantly reduced compared to preoperatively (P < .05); however, the corresponding values at 1 and 3 mm showed no difference. CONCLUSIONS: Correction of high astigmatism with autologous astigmatic lenticule reshaping and rotation surgery is tissue-sparing, predictable, and significantly improves postoperative visual acuity and quality. This method is feasible and safe, with predictability requiring further study. This novel surgical approach has potential for patients with high astigmatism that cannot be corrected by conventional refractive surgery. [J Refract Surg. 2024;40(8):e554-e561.].

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BACKGROUND: Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction. RESEARCH QUESTION: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike? METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson's correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles. RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint's positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80). CONCLUSION: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.

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Mental rotation has emerged as an important predictor for success in science, technology, engineering, and math fields. Previous studies have shown that males and females perform mental rotation tasks differently. However, how the brain functions to support this difference remains poorly understood. Recent advancements in neuroimaging techniques have enabled the identification of sex differences in large-scale brain network connectivity. Using a classic mental rotation task with functional magnetic resonance imaging, the present study investigated whether there are any sex differences in large-scale brain network connectivity for mental rotation performance. Our results revealed that, relative to females, males exhibited less cross-network interaction (i.e. lower inter-network connectivity and participation coefficient) of the visual network but more intra-network integration (i.e. higher intra-network connectivity and local efficiency) and cross-network interaction (i.e. higher inter-network connectivity and participation coefficient) of the salience network. Across all participants, mental rotation performance was negatively correlated with cross-network interaction (i.e. participation coefficient) of the visual network, was positively correlated with cross-network interaction (i.e. inter-network connectivity) of the salience network, and was positively correlated with intra-network integration (i.e. local efficiency) of the somato-motor network. Interestingly, the cross-network integration indexes of both the visual and salience networks significantly mediated sex difference in mental rotation performance. The present findings suggest that large-scale brain network connectivity may constitute an essential neural basis for sex difference in mental rotation, and highlight the importance of considering sex as a research variable in investigating the complex network underpinnings of spatial cognition.

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BACKGROUND: In walking in healthy adults, rotation of the hip joint affects stride length and shifts the center of gravity, but these are not seen in hip osteoarthritis which affects gait. In gait of total hip arthroplasty, there are few reports on changes in the horizontal plane. This study clarified the preoperative and early postoperative gait characteristics of patients undergoing total hip arthroplasty. METHODS: The analysis included 12 females who underwent initial total hip arthroplasty using a posterolateral approach. Gait was measured pre and postoperatively using a three-dimensional motion analysis device. Statistics were compared pre and postoperative range of motion, muscle strength, walking speed, stride length, gravity movement distance, trunk angle, hip joint angle, and joint moment. FINDINGS: The maximum hip abduction moment and trunk flexion angle to the surgical side were lower than in healthy subjects. The angle of internal rotation during the stance phase was significantly higher in the postoperative period. The distance of the center of gravity shift in the left and right directions was significantly decreased postoperatively. INTERPRETATION: Gait disturbance was seen preoperatively and remained after surgery. Walking after total hip arthroplasty provides the hip joint rotates inward which is closer to normal walking. However, no change was observed in the external rotation moment of the hip joint during walking. We suspect that the invasiveness of the posterolateral approach of total hip arthroplasty affects the muscles for external rotation of the hip joint. This can also cause in gait disturbances.

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Although foot mobility tends to be greater in females, sex-based differences in foot torsional stiffness have not been investigated. It is also unclear whether assessing the medial longitudinal arch (MLA) height reflects foot torsional stiffness. This study included 52 healthy adults (26 females and 26 males) with an average age of 24.6 years. The arch height index was used to assess MLA height. To calculate foot torsional stiffness, a custom-built torque meter and a three-dimensional motion analysis system were employed. The forefoot was passively rotated from the maximum eversion to the maximum inversion at a rate of 2.5°/s. The forefoot's resistance torque and rotation angle relative to the rearfoot were recorded. Foot torsional stiffness was defined by establishing the slope of the regression line from 10° eversion to 10° inversion of the torque-angle curve, with the slope subsequently normalized by body weight. Gender differences in foot torsional stiffness and the correlation between MLA height and foot torsional stiffness were investigated. Foot torsional stiffness was significantly lower in females than in males (0.00237 ± 0.00061Nm/°ï½¥kg vs 0.00368 ± 0.00136 Nm/°ï½¥kg, p < 0.001, effect size: r = 0.65, statistical power = 0.99). MLA height was not significantly different between sexes. No significant correlations were found between foot torsional stiffness and MLA height in either sex. Foot torsional stiffness and MLA height reflect different mechanical properties of the foot, emphasizing the need for individual assessment and consideration of sex differences.

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The route to chaos and the phase dynamics of the large scales in a rotating shallow-water model have been rigorously examined through the construction of an autonomous five-mode Galerkin truncated system employing complex variables, useful in investigating how large/meso-scales are destabilized and how their dynamics evolves and transits to chaos. This investigation revealed two distinct transitions into chaotic behaviour as the level of energy introduced into the system was incrementally increased. The initial transition manifests through a succession of bifurcations that adhere to the established Feigenbaum sequence. Conversely, the subsequent transition, which emerges at elevated levels of injected energy, is marked by a pronounced shift from quasi-periodic states to chaotic regimes. The genesis of the first chaotic state is predominantly attributed to the preeminence of inertial forces in governing nonlinear interactions. The second chaotic state, however, arises from the augmented significance of free surface elevation in the dynamical process. A novel reformulation of the system, employing phase and amplitude representations for each truncated variable, elucidated that the phase components present a temporal piece-wise locking behaviour by maintaining a constant value for a protracted interval, preceding an abrupt transition characterised by a simple rotation of ±π, even as the amplitudes display chaotic behaviour. It was observed that the duration of phase stability diminishes with an increase in injected energy, culminating in the onset of chaos within the phase components at high energy levels. This phenomenon is attributed to the nonlinear term of the equations, wherein the phase components are introduced through linear combinations of triads encompassing disparate modes. When the locking durations vary across modes, the resultant dynamics is a stochastic interplay of multiple π phase shifts, generating a stochastic dynamic within the coupled phase triads, observable even at minimal energy injections.

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For the purpose of testing shoulder joint proprioception while controlling for axioscapular muscle recruitment, a novel shoulder thoracohumeral (TH) rotation joint position sense (JPS) measurement device was designed. This device was intended to measure shoulder TH rotation, while also implicitly constraining other upper limb degrees of freedom (DOF) and minimizing cutaneous sensation. The purpose of this study was to determine whether joint motion aside from shoulder TH rotation is being captured by the shoulder JPS measurement device. Upper limb kinematics were collected from 32 participants during joint angle matching trials using the shoulder JPS measurement device. Step wise multiple regression revealed that shoulder TH rotation (ß-Humeral Rotation = 0.409, p < 0.001), and wrist deviation (ß-Wrist Deviation = 0.104, p = 0.008) both contributed a significant unique variance in the prediction of shoulder JPS measurement device rotation. Findings suggest that seated, unconstrained shoulder TH rotation JPS testing protocols in literature may be confounded by contributions from joints both proximal and distal to the shoulder. Researchers should be aware of the limitations of both constrained and unconstrained shoulder TH rotation JPS testing protocols.

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Plants are a paradigm for active shape control in response to stimuli. For instance, it is well known that a tilted plant will eventually straighten vertically, demonstrating the influence of both an external stimulus, gravity, and an internal stimulus, proprioception. These effects can be modulated when a potted plant is additionally rotated along the plant's axis, as in a rotating clinostat, leading to intricate shapes. We use a previously derived rod model to study the response of a growing plant and the joint effects of both stimuli at all rotation speeds. In the absence of rotation, we identify a universal planar shape towards which all shoots eventually converge. With rotation, we demonstrate the existence of a stable family of three-dimensional dynamic equilibria where the plant axis is fixed in space. Further, the effect of axial growth is to induce steady behaviors, such as solitary waves. Overall, this study offers insight into the complex out-of-equilibrium dynamics of a plant in three dimensions and further establishes that internal stimuli in active materials are key for robust shape control.

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PURPOSE: We investigated the vertical implantation of a toric implantable collamer lens (ICL) and compared the rotational stability with that of horizontal implantation. METHODS: This matched comparative study retrospectively reviewed and analyzed data from patients who underwent ICL implantation from 2003-2022 by 1:1 matching vertical and horizontal (V and H toric groups, respectively) implantation patients according to preoperative astigmatism, spherical equivalent, sulcus-to-sulcus, anterior chamber depth, and ICL size. Visual acuity, manifest refraction, vaulting, and rotation were measured 3 months postoperatively. RESULTS: We included 646 eyes (323 each in the V and H toric groups). No statistically significant difference was observed between groups in postoperative visual acuity, refractive error, and astigmatism. Vaulting was lower in the V toric group. (P < 0.001). The mean lens rotation in the V toric group was less than that in the H toric group (1.11 ± 2.84° versus 3.02 ± 10.34°, P = 0.001). The proportion of eyes in the V and H toric groups showing ≥10° of rotation was 2.5% (8 eyes) and 6.5% (21 eyes), respectively (P = 0.014). Despite repositioning from rotation, three (0.9%) and eight (2.5%) eyes required removal owing to lens re-rotation in the V and H toric groups, respectively. CONCLUSION: Toric ICL vertical implantation showed good rotational stability, and appropriate visual acuity correction results with relatively low vaulting. This procedure therefore presents an effective novel method that could replace horizontal toric ICL implantation.

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