Asymmetry In Position Research Articles

Effect of Rapid Maxillary Expansion on Condyle–fossa Relationship in Growing Patients

This study tests whether rapid maxillary expansion (RME) exerts long term effects on interglenoid fossa distance and condyle fossa relationship. Consecutive growing patients aged 8 to 13 years were allocated either to the RME group or control group. Cone-beam computed tomography was performed at baseline and at 6 months. Specific software was used to determine fixed landmarks. Multivariate Analysis of Covariance (MANCOVA) models were used, with time by group interaction, using age as a covariate. Twenty-seven patients with a mean age of 11.4 ± 1.5 years were included. There was an overall significant group by time interaction (p = 0.012, effect size 0.59). Change in the lateral position of the glenoid fossa, the primary outcome, was reached (p = 0.008, effect size 0.258). Change in the laterolateral position of the center of the condyle, and the co-primary outcome was also significant (p = 0.011, effect size = 0.24). Nasal cavity width increased (p = 0.065, effect size = 0.14). There was an initial asymmetry in the horizontal position of the condyles that was carried on with no effect of RME. Rapid maxillary expansion (RME) produces a significant increase in the interglenoid fossa distance and displacement of the mandibular condyles at 6 months in growing patients compared to a control group. The current study shows that RME is effective during growth, widening the interglenoid fossa distance and the lateral positions of the condyles and eventually enlarging the nasal cavity, without causing asymmetry.

Acute effect of biomechanical foot orthotics on gross efficiency in cyclists affected by an anatomic asymmetry in time trial position

Cyclist position on his bicycle and individual anthropometric parameters are very important to optimise pedalling biomechanics (Bini et al. 2011). Postural imbalance can lead to increase joint stre...

Interaction between unilateral transverse disorders and the sagittal dimension: What measures are needed?

Dysfunctional deviations such as dysfunctional swallowing and chewing manifest as transverse arch discrepancies giving rise to positional asymmetry of the condyles and glenoid fossae with a more or less significant skeletal impact. This results almost inevitably in asymmetric occlusion in the sagittal dimension. Drawing on clinical cases, we will show which treatment strategies to adopt and which occlusal criteria to observe for finishing and stability.

Disturbance scaling in bidirectional vehicle platoons with different asymmetry in position and velocity coupling

This paper considers a string of vehicles where the local control law uses the states of the vehicle’s immediate predecessor and follower. The coupling towards the preceding vehicle can be chosen different to the coupling with the following vehicle, which is referred to as an asymmetric bidirectional string. Further, the asymmetry for the velocity coupling can be chosen differently to the asymmetry in the position coupling. It is investigated how the effect of the disturbance on the control errors in the string depends on the string length. It is shown, that in case of symmetric position coupling and asymmetric velocity coupling, linear scaling can be achieved. For symmetric interactions, the errors scale quadratically in the number of vehicles. When the coupling in position is asymmetric, exponential scaling may occur or the system might even become unstable. The paper thus gives a comprehensive overview of the achievable performance in linear, asymmetric, bidirectional platoons. The results reveal that symmetry in the position coupling and asymmetry in velocity coupling qualitatively improve the performance of the string. Extensive numerical results illustrate the theoretical findings.

Exchange bias and strain effect co-modulated magnetic symmetry in La0.6Sr0.4MnO3/orthorhombic-YMnO3 multiferroic heterostructures

The exchange bias and strain effect co-modulated magnetic symmetry in all oxide La0.6Sr0.4MnO3 (LSMO) and orthorhombic YMnO3 (YMO) multiferroic heterostructures were studied. Because of the lattice mismatch between the LSMO and YMO layers, the LSMO layer exhibits a 90° rotation growth on the YMO layer. The strain induced growth not only leads to a 90° phase shift in the anisotropic magnetoresistance (AMR) curves, but also brings a two-fold symmetric magnetoelastic coupling energy along the LSMO direction. With the incorporation of magnetoelastic coupling energy and exchange coupling energy, the exchange bias induced torque shows a phase shift and causes the asymmetry of the peak position and value in the AMR curves. This work illustrates a modulated magnetic symmetry in ferromagnetic/multiferroic systems by interfacial exchange coupling and strain effect, which will benefit the design of magnetoelectric devices.

Discriminative Thresholds in Facial Asymmetry: A Review of the Literature.

Facial symmetry is intimately correlated with attractiveness. Perfect facial symmetry is disconcerting and a degree of facial asymmetry is considered normal. There is a lack of data on the limits of normality across facial subunits. This systematic review aims to establish categories of facial asymmetry perception for facial aesthetic units by establishing a discriminative threshold of "deformity perception" across facial subunits and a threshold for intervention (unacceptable asymmetry). A review of the literature was performed across Medline and Embase databases using OvidSP. All prospective studies evaluating the perception of progressive facial asymmetry in laymen or clinicians using a two- or three-dimensional model were included. Studies that did not evaluate rates of perception at varying degrees of asymmetry were excluded as these did not allow for the identification of a perceptive threshold. Each facial feature possesses a unique threshold of perception defined by an abrupt, statistically significant increase in detection. Asymmetry of the eyelid position at rest is the most sensitive facial feature (perceptive threshold, 2 mm) (P < 0.02). This is followed by deviations of the oral commissure (3 mm) (P < 0.001), brow position (3.5 mm) (P < 0.001), nasal tip deviation (4 mm) (P < 0.001), and chin deviation (6 mm) (P < 0.001). Desire for surgery for worsening deformities beyond the intervention threshold is characterized by an exponential, rather than linear, correlation. Categories of facial asymmetry perception establish a framework to counsel patients with facial asymmetries, and are a valuable adjunct to clinical judgment in the management of static and dynamic facial deformities.

Asymmetries in the Coordinated Direct Investment Survey: What Lies Behind?

This paper analyzes asymmetries in direct investment positions reported in the Coordinated Direct Investment Survey (CDIS) following a top down approach. First, it examines asymmetries at global level; second, it examines asymmetries between CDIS reported and derived data for individual economies; and third, the paper analyzes data at bilateral economy level. Then, the paper explores seven main reasons for asymmetries, including those arising even when economies follow international standards. Finally, the paper includes a section on addressing bilateral asymmetries and concludes with specific planned actions to reduce asymmetries, including initiatives led by international organizations.

Effect of doping symmetry on electron spin relaxation dynamics in (110) GaAs/AlGaAs quantum wells

Considerable interest has been aroused in the study of the spin dynamics in semiconductors due to its potential applications in spintronics and quantum computation. In this paper, time-resolved circularly polarized pump-probe spectroscopy is used to study the carrier density dependences on the electron spin relaxation in approximately symmetrical and completely asymmetrical doping (110) GaAs/AlGaAs quantum wells. With the increase of the carrier density, the spin relaxation time first increases and then decrease obviously in both of the quantum wells, and the measured spin relaxation time of the approximately symmetrical doping quantum wells is always longer than that of the asymmetrical doping one. By analysis, we find that the spin relaxation is not dominated only by the Bir-Aronov-Pikus (BAP) mechanism in (110) GaAs quantum wells, that though the Dresselhaus spin-orbit coupling does not lead to any spin relaxation, the asymmetry of the doping position contributes to the asymmetry of potential energy structure, thus the built-in electric field which can induce the Rashba spin-orbit coupling to appear, and that the effective magnetic field induced by the Rashba spin-orbit coupling normal to the growth direction can lead to spin relaxation along the growth direction. Therefore, the Dyakonov-Perel (DP) mechanism plays an important role in asymmetrical doping (110) GaAs/AlGaAs quantum wells. In the approximately symmetrical and completely asymmetrical doping (110) GaAs/AlGaAs quantum wells, the DP mechanism dominates the spin relaxation at low carrier density, thus the spin relaxation time increases with carrier density increasing due to the strengthening of the electron-electron scattering and the decreasing of the momentum relaxation time. However, at high carrier density, BAP mechanism plays an important role, thus the spin relaxation time decreases obviously with carrier density increrasing, but the decay rates in both of the quantum wells are slower than that in the casethat only BAP mechanism dominates, because both the DP and BAP mechanism play an important role. The strength of the Rashba spin-orbit coupling depends on the symmetry of the quantum well. The DP mechanism in a completely asymmetrical doping quantum well is stronger than that in an approximately symmetrical doping quantum wells, thus the decay rate in a completely asymmetrical doping quantum wells is always slower than that in an approximately symmetrical doping quantum wells, and the spin relaxation time in a completely asymmetrical doping quantum wells is shorter than that in an approximately symmetrical doping quantum wells.

Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry.

ObjectiveTreating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar.MethodsCone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association.ResultsThe faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar.ConclusionsAsymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

Feasibility of vocal fold abduction and adduction assessment using cine-MRI

ObjectiveDetermine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI)MethodsCine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC).ResultsVF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44).ConclusionCine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability.Key points• Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction.• New quantitative metrics are derived from VF position and abduction potential.• Cine-MRI able to depict the difference between normal and abnormal VF mobility.• Cine-MRI derived quantitative metrics have good repeatability.

The Eye of the Beholder: Violence as a Social Process

A triangular reconstruction of the social dynamics of violence offers a means to bridge the gap between research on the micro- and meso-level dynamics of violent interaction on the one hand, and theories of power and domination on the other. The origins of this approach are found in the phenomenological programme of social science violence research formulated by German sociologists in the 1990s (Sofsky, von Trotha, Nedelmann, and others). Reconsidering their arguments in the framework of social constructivism, this article reconstructs violence as a triangular process evolving between «performer», «target» and «observer». Disentangling the dimensions of the somatic and the social shows, however, that these are not the fixed roles of agents, but changeable modes of experiencing violence. Violent interaction uses the suffering body to stage a positional asymmetry, i.e. a distinction between strength and weakness, between above and below, which can be exploited for the production and reproduction of social order.

The temporal topography of the N-Methyl- N-nitrosourea induced photoreceptor degeneration in mouse retina.

Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases characterized by the progressive photoreceptors apoptosis. The N-Methyl- N-nitrosourea (MNU) is an alkylating toxicant which could induce photoreceptor apoptosis resembling that of the hereditary RP. However, the detailed process pattern of this degeneration remains poorly characterized. We systemically explored the topography of the photoreceptor degeneration in the MNU treated mouse, and related these spatial data with the time-dependent characteristics of retinal pathology. These temporal topographic data delineated sequential scenes of the progressive photoreceptor degeneration in the MNU treated retinas: focal photoreceptors showed different vulnerabilities to the MNU toxicity and displayed a distinctive spatial- and time-dependent progression. Moreover, the positional asymmetry between the retinal quadrants firstly provided instructive information about the unique toxicology properties of the MNU. Further mechanism study suggested that the up-regulation of Bax and Calpain-2, rather than the Caspase-3, should be responsible for the asymmetry in the MNU induced photoreceptor degeneration. Together with the comparative sensitivities to the neurotoxicity of MNU between two photoreceptor populations, these topographic data would facilitate the standardization of analytic parameters related to the MNU induced RP model, and enhance its application in the therapeutic explorations of human RP.

Syllable Structure Universals and Native Language Interference in Second Language Perception and Production: Positional Asymmetry and Perceptual Links to Accentedness.

The present study investigated how syllable structure differences between the first Language (L1) and the second language (L2) affect L2 consonant perception and production at syllable-initial and syllable-final positions. The participants were Mandarin-speaking college students who studied English as a second language. Monosyllabic English words were used in the perception test. Production was recorded from each Chinese subject and rated for accentedness by two native speakers of English. Consistent with previous studies, significant positional asymmetry effects were found across speech sound categories in terms of voicing, place of articulation, and manner of articulation. Furthermore, significant correlations between perception and accentedness ratings were found at the syllable onset position but not for the coda. Many exceptions were also found, which could not be solely accounted for by differences in L1–L2 syllabic structures. The results show a strong effect of language experience at the syllable level, which joins force with acoustic, phonetic, and phonemic properties of individual consonants in influencing positional asymmetry in both domains of L2 segmental perception and production. The complexities and exceptions call for further systematic studies on the interactions between syllable structure universals and native language interference with refined theoretical models to specify the links between perception and production in second language acquisition.

Laterality of head position at rest in mallard (&lt;em&gt;Anas platyrhynchos&lt;/em&gt;) from two distinct northern wintering groups

Motor asymmetries are wide spread among vertebrate and invertebrate animals. More frequently asymmetries in the use of paired appendages and turns of the body in space become the subject of research. Unpaired organs, positioned along the long axis of the body become the subjects of investigation of the functional asymmetries less often. Here we performed a preliminary estimation of populational characteristics of asymmetry in the turn of the head while resting in Mallards (Anas platyrynchos) from two distinct wintering groups. On tracks along the banks of rivers and channels in the center of Saint-Petersburg, Russia, and along the Buksnesfjord at the Vestvagøy island (Lofoten Islands, Norway Sea, Norway), we recorded the position of the head (under the left wing, or under the right wing) in resting birds ones for each individual. Totally we recorded head position in 151 individuals from Saint-Petersburg and in 77 individuals at Vestvagøy. Individuals keeping heads under the right wing were predominant in Saint-Petersburg, while at Vestvagøy the proportion of «left» and «right» individuals did not differ significantly from 1:1. Difference between the populations was significant, while sex differences in both populations were not found. We discuss possible reasons for the differences in population characteristics of asymmetry in the head position («head-under-wing»), particularly conditions of wintering, birds behaviour. We conclude that the study of different wintering groups of mallards can be possibly perspective for estimation of population status by assessment of relative proportion of «left» and «right» birds.

Cone-Beam Computed Tomography Assessment of Lower Facial Asymmetry in Unilateral Cleft Lip and Palate and Non-Cleft Patients with Class III Skeletal Relationship.

IntroductionTo evaluate, using cone-beam computed tomography (CBCT), both the condylar-fossa relationships and the mandibular and condylar asymmetries between unilateral cleft lip and palate (UCLP) patients and non-cleft patients with class III skeletal relationship, and to investigate the factors of asymmetry contributing to chin deviation.MethodsThe UCLP and non-cleft groups consisted of 30 and 40 subjects, respectively, in mixed dentition with class III skeletal relationships. Condylar-fossa relationships and the dimensional and positional asymmetries of the condyles and mandibles were examined using CBCT. Intra-group differences were compared between two sides in both groups using a paired t-test. Furthermore, correlations between each measurement and chin deviation were assessed.ResultsIt was observed that 90% of UCLP and 67.5% of non-cleft subjects had both condyles centered, and no significant asymmetry was found. The axial angle and the condylar center distances to the midsagittal plane were significantly greater on the cleft side than on the non-cleft side (P=0.001 and P=0.028, respectively) and were positively correlated with chin deviation in the UCLP group. Except for a larger gonial angle on the cleft side, the two groups presented with consistent asymmetries showing shorter mandibular bodies and total mandibular lengths on the cleft (deviated) side. The average chin deviation was 1.63 mm to the cleft side, and the average absolute chin deviation was significantly greater in the UCLP group than in the non-cleft group (P=0.037).ConclusionCompared with non-cleft subjects with similar class III skeletal relationships, the subjects with UCLP showed more severe lower facial asymmetry. The subjects with UCLP presented with more asymmetrical positions and rotations of the condyles on axial slices, which were positively correlated with chin deviation.

Determination of Fermi contour and spin polarization ofν=32composite fermions via ballistic commensurability measurements

We report ballistic transport commensurability minima in the magnetoresistance of $\nu =3/2$ composite fermions (CFs). The CFs are formed in high-quality two-dimensional electron systems confined to wide GaAs quantum wells and subjected to an in-plane, unidirectional periodic potential modulation. We observe a slight asymmetry of the CF commensurability positions with respect to $\nu=3/2$, which we explain quantitatively by comparing three CF density models and concluding that the $\nu=3/2$ CFs are likely formed by the minority carriers in the upper energy spin state of the lowest Landau level. Our data also allow us to probe the shape and size of the CF Fermi contour. At a fixed electron density of $\simeq 1.8 \times 10^{11}$ cm$^{-2}$, as the quantum well width increases from 30 to 60 nm, the CFs show increasing spin-polarization. We attribute this to the enhancement of the Zeeman energy relative to the Coulomb energy in wider wells where the latter is softened because of the larger electron layer thickness. The application of an additional parallel magnetic field ($B_{||}$) leads to a significant distortion of the CF Fermi contour as $B_{||}$ couples to the CFs' out-of-plane orbital motion. The distortion is much more severe compared to the $\nu=1/2$ CF case at comparable $B_{||}$. Moreover, the applied $B_{||}$ further spin-polarizes the $\nu=3/2$ CFs as deduced from the positions of the commensurability minima.

Achieving Symmetry in Unilateral DIEP Flap Breast Reconstruction: An Analysis of 126 Cases over 3 Years.

Many patients who prefer breast reconstruction by a deep inferior epigastric artery perforator (DIEP) flap often lack skin laxity at the lower abdomen. Recreating a symmetrical breast with various degrees of ptosis is one of the most difficult procedures. In this report, varied DIEP flap shapes were precisely designed on the basis of normal breast ptosis. The reconstructive outcomes were quantitatively evaluated for asymmetry of footprint, volume, breast projection, and nipple position by a 3-dimensional scanning system. One hundred twenty-six cases of unilateral DIEP flap breast reconstruction were successfully performed from January 2009 to July 2012. The maximal flap width ranged from 7.5 to 10.5 cm (mean, 9.0 cm), and the flap length ranged from 28 to 38 cm (mean, 32.5 cm). The discrepancy of the footprint and nipple position did not differ significantly between the reconstructed and normal breasts. However, the reconstructed side had significantly higher breast volume and projection. For patients with a relatively tight abdomen, the flap design and shaping approach we propose achieves a maximal symmetrical outcome and should be considered as a good and reliable option.

Flap failure and aircraft controllability: Developments in asymmetry monitoring techniques

The asymmetry limitation between left and right wing flap surfaces is one of the most severe requirements for the design of the actuation and control system. When the position asymmetry exceeds a defined value, it must be detected and limited by appropriate monitoring devices equipped with a suitable software. In the design of a new flap control system the development of the asymmetry monitoring subsystem plays a very important role and, together with the flap system layout selection, it was and still is a debated matter in the industry. The currently used monitoring technique is based on differential position detection between left and right surfaces. Their use generally slightly reduces the asymmetry, but in some cases it may have an unreliable behavior. To overcome the shortcomings of the previous models, we propose new and different monitoring strategies and assess their positive effects on the maximum asymmetry following a torque tube failure; in particular, the asymmetry reduction coming from the employment of the proposed techniques in the considered operative conditions (typical deployment / retraction flap actuations), with respect to a previous type of technique, can be evaluated in the order of 30%.

Association between cervical and thoracic somatic dysfunction among second-year osteopathic medical students.

The ubiquitous nature of cervical and thoracic somatic dysfunction requires osteopathic physicians to have a strong working knowledge of regional spinal mechanics and their functional and dysfunctional interrelationships. To determine whether cervical and thoracic somatic dysfunction occur concomitantly, particularly somatic dysfunction of the occipitoatlantal (OA) and upper thoracic (T1-T4) region of the spine. A retrospective analysis of cervical and thoracic somatic dysfunction prevalence diagnosed by faculty in second-year osteopathic medical students was conducted. Somatic dysfunction was defined as a vertebral unit possessing any of the following palpatory characteristics: tissue texture changes, asymmetry of motion and relative position, restriction of motion, or tenderness (ie, TART criteria). For each instance of somatic dysfunction diagnosed, the segmental level identifying the superior segment of the involved vertebral unit was recorded, as well as the spinal region (ie, cervical [OA, atlantoaxial (AA), and C2-C7] or thoracic [T1-T12]). Descriptive analyses, a Pearson χ(2) test, and a regression model using an analysis of variance were performed on the data. Among 338 students included in the study, the following 5 vertebral segments were found to have the highest prevalence of somatic dysfunction: OA (257 [76.0%]), C3 (257 [76.0%]), T3 (247 [73.1%]), T5 (226 [66.9%]), and T4 (223 [66.0%]). A Pearson χ(2) test of association between the OA vertebral segment and the following segments were found to be statistically significant: AA (P=.024), C2 (P=.032), and T4 (P=.045). An analysis of variance revealed statistical significance between the prevalence of upper cervical (OA, AA, C2) somatic dysfunction and the prevalence of upper thoracic (P<.001) and midthoracic (T5-T8) (P<.001) somatic dysfunction; the prevalence of lower cervical (C3-C7) (P=.74) and lower thoracic (T9-T12) (P=.085) somatic dysfunction was not found to be significant. A statistically significant association between cervical somatic dysfunction and thoracic somatic dysfunction was confirmed. In addition, there was a statistically significant association between dysfunction of the OA and the AA, C2, and T4 vertebral segments. These results suggest that the number of dysfunctional vertebral segments in the upper thoracic and midthoracic spinal regions is directly proportional to the number of dysfunctional segments found in the upper cervical spinal region.

Assessing Palpation Thresholds of Osteopathic Medical Students Using Static Models of the Lumbar Spine

Although spinal somatic dysfunction diagnosis is taught at all colleges of osteopathic medicine, few objective measures have been used to evaluate student accuracy. To assess the palpatory skills of osteopathic medical students in evaluating positional asymmetry in the transverse plane using static block transverse process and lumbar spine models. For this observational study, first-year osteopathic medical students completed 3 palpatory assessments using uncovered and covered block transverse process and lumbar spine models to simulate a range of positional asymmetries of the transverse processes. With use of logistic regression, 80%, 90%, and 95% thresholds were defined as the magnitude of asymmetry for which the predicted probability of students correctly determining the direction of asymmetry exceeded a specified amount (.80, .90, or .95). A total of 346 students completed the assessments. For the uncovered block transverse process model (assessment 1), students correctly identified the direction of asymmetry with .89 probability at 1 mm of asymmetry (80% threshold), .94 probability at 2 mm (90% threshold), and .95 probability at 3 mm (95% threshold). For the covered block transverse process model, students correctly identified the direction of asymmetry with .80 probability at 1 mm (80% threshold), .92 probability at 2 mm (90% threshold), and .98 probability at 3 mm (95% threshold) by the third assessment. For the uncovered lumbar spine model (assessment 2), students correctly identified the direction of asymmetry with .93 probability at 2 mm (80% and 90% thresholds) and .95 probability at 3 mm (95% threshold). For the covered lumbar spine model (assessments 2 and 3), students correctly identified the direction of asymmetry with .87 probability at 4 mm (80% threshold); 90% and 95% thresholds were not reached with the range of asymmetries tested. Most first-year osteopathic medical students were able to discern the direction of positional asymmetry of transverse processes on static models. Depending on the model type, student performance improved (block transverse process models) or declined (lumbar spine models) over time. Future studies should evaluate whether accuracy of palpating lumbar spine models translates to accuracy of palpating human lumbar spines.