Regression-Based Machine Learning for Predicting Lifting Movement Pattern Change in People with Low Back Pain

Machine learning (ML) algorithms are crucial within the realm of healthcare applications. However, a comprehensive assessment of the effectiveness of regression algorithms in predicting alterations in lifting movement patterns has not been conducted. This research represents a pilot investigation using regression-based machine learning techniques to forecast alterations in trunk, hip, and knee movements subsequent to a 12-week strength training for people who have low back pain (LBP). The system uses a feature extraction algorithm to calculate the range of motion in the sagittal plane for the knee, trunk, and hip and 12 different regression machine learning algorithms. The results show that Ensemble Tree with LSBoost demonstrated the utmost accuracy in prognosticating trunk movement. Meanwhile, the Ensemble Tree approach, specifically LSBoost, exhibited the highest predictive precision for hip movement. The Gaussian regression with the kernel chosen as exponential returned the highest prediction accuracy for knee movement. These regression models hold the potential to significantly enhance the precision of visualisation of the treatment output for individuals afflicted with LBP.

Assessing the validity of two-dimensional video analysis for measuring lower limb joint angles during fencing lunge

Introduction

The fencing lunge (lunge), characterized by minimal body rotation, offers a movement well-suited for 2D video analysis. However, to the best of our knowledge, the validity of 2D video analysis for fencing has not been verified. This study aimed to validate 2D video analysis by comparing lower limb joints (hip, knee, and ankle joints) angles during lunge using both 2D video analysis and 3D motion analysis methods.

Methods

Twenty-two male fencers performed lunge trials that were simultaneously recorded using eight motion capture cameras (Qualisys Miqus M1) and two digital video cameras (Sony AX-450 and AX450a).

Results

The 2D video analysis results exhibited an extremely large correlation in knee joint angles of the front and rear legs in the sagittal with those from 3D motion analysis (r = 0.93-0.99). However, while a robust correlation was found between the ankle joint angles of the front and rear legs (r = 0.82-0.84), a large bias was also observed (-5.23° to -21.31°). Conversely, for the hip joints of the rear leg, a moderate correlation (r = 0.31) and a large bias (-10.89°) were identified.

Conclusions

The results of this study will contribute to the development of coaching using 2D video analysis in competition settings because such analysis can be a useful alternative to 3D motion analysis when measuring the knee joint angle of the front leg and rear leg in the sagittal plane. However, for the ankle joint angle, further research on the optimal shooting position and height of the digital video camera is needed, whereas for the hip joint angle, 3D motion analysis is recommended at this time.

Evaluating the Accuracy of Upper Limb Movement in the Sagittal Plane among Computer Users during the COVID-19 Pandemic

(1) Background: The most common musculoskeletal pathology among healthcare professionals is neck and/or shoulder pain. The aim of this study was to determine the dominant upper limb functionality concerning the ability to replicate a given movement pattern among employees reporting neck or upper limb pain while using a computer during the COVID-19 pandemic. (2) Methods: The study was conducted from March to April 2021 on a group of 45 medical employees who used a computer workstation for 4 to 6 h of their working time. In the design of this study, three study groups were created: a group of patients with pain syndrome of segment C5/C7 of the spine, a group of patients with shoulder pain syndrome, and a control group of healthy volunteers. (3) Results: The examined groups significantly differed in the correctness of performing the given movement (p = 0.001) and the minimum value of inclination during the exercise session (p = 0.026), as well as the maximum lowering (p = 0.03) in relation to the control group. (4) Conclusions: The VECTIS device can be used to assess the accuracy of reflecting the prescribed movement of the upper limb in rehabilitation programs for patients with cervical spine pain syndrome and shoulder pain syndrome.

Finite element analysis of Kirschner wire fixation for lateral condyle fracture in children in the sagittal plane

OBJECTIVE

This study aims to find the optimal arrangement of the Kirschner wire (K-wire) in the sagittal plane for fixation of a pediatric lateral condylar humeral fracture (Milch type II) by using finite element analysis (FEA).

METHODS

A model of lateral condyle fracture in a 6-year-old boy was developed, and an XYZ coordinate system was established based on this model. The YZ plane was defined as the sagittal plane to investigate the impact of the angle formed by the first and second K-wires on stability. Two configurations were studied for each angle: parallel and divergent. Evaluation indicators included the maximum displacement of the fracture fragment and the maximum von Mises stress in the pins and bone.

RESULTS

The model with a -60° angle showed the best performance in both evaluation indicators. The parallel and divergent pin configurations had different performances in each group. The displacement results for negative angles were similar, and this result was better than those for positive angles.

CONCLUSION

We successfully created a model of pediatric lateral condyle humerus fracture (Milch type II) and performed K-wire fixation with varying sagittal plane configurations, combined with FEA. Our findings demonstrate that the angle of -60° between the two pins in the sagittal plane provided the highest level of stability, with divergent configurations proving superior to parallel pinning at this angle.

Creation and Evaluation of a Severity Classification of Hyperkyphosis and Hypolordosis for Exercise Therapy

The rise in the occurrence of musculoskeletal disorders, such as thoracic hyperkyphosis (THK) or lumbar hypolordosis (LHL), is a result of demographic changes. Exercise therapy is an effective approach that can reduce related disabilities and costs. To ensure successful therapy, an individualized exercise program adapted to the severity of the disorder is expedient. Nevertheless, appropriate classification systems are scarce. This project aimed to develop and evaluate a severity classification focused on exercise therapy for patients with THK or LHL. A multilevel severity classification was developed and evaluated by means of an online survey. Reference limits of spinal shape angles were established by data from video rasterstereography of 201 healthy participants. A mean kyphosis angle of 50.03° and an average lordosis angle of 40.72° were calculated as healthy references. The strength of the multilevel classification consisting of the combination of subjective pain and objective spinal shape factors was confirmed by the survey (70% agreement). In particular, the included pain parameters were considered relevant by 78% of the experts. Even though the results of the survey provide important evidence for further analyses and optimization options of the classification system, the current version is still acceptable as therapeutic support.

Mechanical complications and patient-reported outcome measures associated with high pelvic incidence and persistent pelvic retroversion: the Roussouly "false type 2" profile

OBJECTIVE

The objective of this paper was to report mechanical complications and patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) patients with a Roussouly "false type 2" (FT2) profile.

METHODS

ASD patients treated from 2004 to 2014 at a single center were identified. Inclusion criteria were pelvic incidence ≥ 60° and a minimum 2-year follow-up. FT2 was defined as a high postoperative pelvic tilt (PT), as defined by the Global Alignment and Proportion target, and thoracic kyphosis < 30°. Mechanical complications, defined as proximal junctional kyphosis (PJK) and/or instrumentation failure, were determined and compared. Scoliosis Research Society-22r (SRS-22r) scores were compared between groups.

RESULTS

Ninety-five patients (normal PT [NPT] group 49, FT2 group 46) who met the inclusion criteria were identified and studied. Most surgeries were revisions (NPT group 30 [61%], FT2 group 30 [65%]), and most were performed via a posterior-only approach (86%) (mean ± SD 9.6 ± 5 levels). Proximal junctional angles increased after surgery in both groups, without differences between groups. Neither rates of radiographic PJK (p = 0.10), revision for PJK (p = 0.45), nor revision for pseudarthrosis (p = 0.66) were different between groups. There were no differences between groups for SRS-22r domain scores or subscores.

CONCLUSIONS

In this single-center experience, patients with high pelvic incidence fixed with persistent lumbopelvic parameter mismatch and engaged compensatory mechanisms (Roussouly FT2) had mechanical complications and PROMs not different from those with normalized alignment parameters. Compensatory PT may be acceptable in some cases of ASD surgery.

Radiographic patterns and characteristics of sagittal profiles in normal spinopelvic curvatures: An explicit depiction of the distribution of lumbar vertebral bodies and discs

The current study aimed to investigate the sagittal morphology of the spinopelvic complex and the components of the lumbar spine in the normal population. In total, 132 adult volunteers were retrospectively evaluated and divided into four groups according to the Roussouly classification. Statistical analysis of radiological parameters, including lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL, LL-TK, lumbar vertebral lordosis from L1 to L5 (L1L-L5L), the intervertebral angle from L1-L2 to L5-S1 (IVA1-2-IVA5-1), segmental lordosis from L1 to L5 (S1L-S5L), the proportion of L1-L5 (L1%-L5%), the proportion of the intervertebral angle from L1-L2 to L5-S1 (IVA1-2%-IVA5-1%), and proportion of segmental lordosis from L1 to L5 (S1L%-S5L%), was performed. Based on the classification, type II (n = 46) was the most common, followed by type I (n = 39), type III (n = 36), and type IV (n = 11). The quantitative values of the sagittal parameters of the four groups were obtained. Results showed a significant difference in terms of LL, PI, SS, and LL-TK. Further, L1%, L2%, L3%, IVA1-2%, IVA2-3%, S1L%, S2L%, and S3L% had an increasing trend. PI was positively correlated with LL, S1L, S2L, S3L, S4L, S1L%, and S2L%, but not with S5L%. In conclusion, pelvic parameters had a significant effect on lumbar curvature and lordosis distribution. Further, the abovementioned results were beneficial for individual surgical decision-making regarding targeted intervertebral angle, screw-insertion dimension, and rod contouring.

Generating High-Resolution CT Slices from Two Image Series Using Deep-Learning-Based Resolution Enhancement Methods

Medical image super-resolution (SR) has mainly been developed for a single image in the literature. However, there is a growing demand for high-resolution, thin-slice medical images. We hypothesized that fusing the two planes of a computed tomography (CT) study and applying the SR model to the third plane could yield high-quality thin-slice SR images. From the same CT study, we collected axial planes of 1 mm and 5 mm in thickness and coronal planes of 5 mm in thickness. Four SR algorithms were then used for SR reconstruction. Quantitative measurements were performed for image quality testing. We also tested the effects of different regions of interest (ROIs). Based on quantitative comparisons, the image quality obtained when the SR models were applied to the sagittal plane was better than that when applying the models to the other planes. The results were statistically significant according to the Wilcoxon signed-rank test. The overall effect of the enhanced deep residual network (EDSR) model was superior to those of the other three resolution-enhancement methods. A maximal ROI containing minimal blank areas was the most appropriate for quantitative measurements. Fusing two series of thick-slice CT images and applying SR models to the third plane can yield high-resolution thin-slice CT images. EDSR provides superior SR performance across all ROI conditions.

Neglected problem: Influence of school bag on lumbar segment in children

BACKGROUND AND OBJECTIVES

School bag (SB) load causes significant changes in the height and symmetry of the intervertebral discs at each level of the spine from T12-L1 to L5-S1. This study aims to determine the change in the size of the lumbar segment angle at a particularly critical point L3-L4 of the spine in relation to the load of the average weight of SB in healthy male children (students) at standing and after 2-minute gait.

METHODS

47 boys, aged 12.2 ± 0.92 years, underwent photogrammetric measurements in the sagittal plane in statics and dynamics, walking on a laboratory treadmill. Measurements were repeated with the weight of SB with a constant load of 6,251 kg, which represents 13.78% of the average body weight of our sample. The lumbar angle (LA) connecting the point of the big toe, the lumbar point L3-L4 and the processus spinosus C7 was measured. In gait, LA was measured in the phases of the middle support and the initial contact of the heel.

RESULTS

T-test of paired samples was used to estimate the change in LA at standing from 4.953° and walking phases from 6.295° to 7.332° in relation to the unloaded state, and the value of the effect size (ES) indicates that the impact of SB load is significant.

CONCLUSIONS

Cumulatively, microtraumas caused by SB load significantly affect the increase in intervertebral pressure at the L3-L4 point, which is susceptible to degenerative processes and which can be the cause of lumbar syndrome (LS). Preventive measures are needed in order to lighten SB in this population and introduce up to 10% of students' body weight into the safe zone.

Feasibility of Double Anterior Odontoid Screw: A CT-Based Morphometric Analysis of the Axis in Adult Indian Population

Background

The fractures of the odontoid process constitute 10% of all cervical spine injuries. Odontoid screw placement, although technically challenging, in indicated cases is the ideal treatment. Hence, a thorough knowledge of the odontoid dimensions is necessary prior to the surgical endeavor, more so for planning double odontoid screws.

Materials and Methods

A prospective morphometric analysis of retrospective data of 250 patients was acquired at our institute using Somatom Definition edge 128 slice 64-row detector Siemens CT scanner. The dimensions of the odontoid process were measured at the waist (narrowest portion), widest diameter both in anteroposterior and transverse diameters. The dimensions of the C2 vertebra were measured at the level of the superior and inferior endplate in both the planes.

Results

A total of 250 patients were evaluated with age ranging from 1 to 80 years. Males constituted 174 (69.6%) and 76 (30.4%) were females. The mean transverse diameter (TD) at the odontoid waist (narrowest diameter) was 8.66 mm. The mean TD at the widest point of odontoid was 9.68 mm. Mean anteroposterior (AP) diameter 2.5 mm away from the midline on the left side at the level of the waist was 9.51 mm and 2.5 mm on the right of midline was 9.01 mm. The mean AP diameter at the C2 base was 15.824 mm in males and 14.833 mm in females (P < 0.001).

Conclusion

Double odontoid screw insertion is feasible in only 36% of Indians in the transverse plane, whereas 98.4% of the odontoids can accommodate double screws in the sagittal plane.

Sagittal plane alignment affects the strength of pin fixation in supracondylar humerus fractures

Closed reduction with percutaneous pin fixation is commonly used to treat pediatric supracondylar humerus fractures. Various pin configurations of varying biomechanical strength have been described. However, to our knowledge, no biomechanical study has focused on pin alignment in the sagittal plane. Our goal was to compare the stability of fixation using 3 different pin constructs: 3 lateral pins diverging in the coronal plane but parallel in the sagittal plane (3LDP), 3 lateral pins diverging in the coronal and sagittal planes (3LDD), and 2 crossed pins (1 medial and 1 lateral).Transverse fractures were made through the olecranon fossa of 48 synthetic humeri, which were then reduced and pinned in the 3LDP, 3LDD, and crossed-pin configurations (16 specimens per group) using 1.6-mm Kirschner wires. The sagittal plane pin spread was significantly greater in the 3LDD group than in the 3LDP group, whereas we found no difference in the coronal plane. Sagittal extension testing was performed from 0° to 20° at 1°/s for 10 cycles using a mechanical torque stand. The torque required to extend the distal fragment 20° from neutral was compared between groups using one-way analysis of variance with multiple comparison post-hoc analysis. P values ≤.05 were considered significant.The 3LDD configuration was more stable than the 3LDP and crossed-pin configurations. The mean torque required to displace the pinned fractures was 5.7 Nm in the 3LDD group versus 4.1 Nm in the 3LDP group and 3.7 Nm in the crossed-pin group (both, P < .01). We found no difference in stability between the 3LDP and crossed-pin groups (P = .45).In a synthetic biomechanical model of supracondylar humerus fracture, sagittal alignment influenced pin construct stability, and greater pin spread in the sagittal plane increased construct stability when using 3 lateral pins. The lateral pin configurations were superior in stability to the crossed-pin configuration.Level of Evidence: Level V.

Scoliosis and Gastroesophageal Reflux Disease in Adults

Introduction

Degenerative scoliosis most commonly presents with lower back pain. Literature suggests that adults who have degenerative scoliosis are at greater risk of both hiatal hernia and gastroesophageal reflux disease (GERD). The objective of this study was to evaluate scoliosis as being the risk factor of GERD in adults.

Materials and methods

This prospective study was conducted at Dow University of Health Sciences over a period of two years (May 2018 to April 2020). The investigation included 210 participants with spinal disorders. The mean age was 71.6±9.6 years. The X-rays of the participants’ whole spine were taken in a standing position, in the sagittal and coronal planes. Symptoms of GERD were measured through the quality of life and utility evaluation survey technology (QUEST) score, taking six points as cutoff values. The evaluation was done using radiographs to determine any relationship between spinal disorders and GERD. Negative values were analyzed in a right-sided convex curve while positive values in the left-sided convex curve were viewed in the coronal plane. Degenerative scoliosis was explained as a lumbar/thoracolumbar Cobb angle of more than 10 degrees. Univariate and multivariate logistic regression analyses were done to assess the risk factors related to GERD.

Results

Out of 210 patients, 146 were found to have degenerative scoliosis at the level of the lumbar and thoracolumbar spine. Fifty-two patients had a right convex curve, and 94 had a left convex curve. Sixty-nine patients had GERD. According to the analysis of the multivariate logistic regression, the Cobb angle was highly related to GERD (p-value <0.05 and odds ratio of 1.031). The participants were grouped according to the Cobb angle of curve at the lumbar spine (less than 30 degrees with a large right-sided convex curve, 30 and more with a small curve, and more than 30+ degrees with a large left-sided convex curve). The study revealed that a large left-sided convex curve was highly related to GERD, with a p-value <0.05 and odds ratio of 10.935.

Conclusions

The left-sided large convex curve at the thoracolumbar or lumbar spine, especially when the Cobb angle was more than 30 degrees, was highly associated with GERD. Therefore, the symptoms of GERD should be monitored in the elderly population with degenerative scoliosis.

Progressive Tibial Bearing Sagittal Plane Conformity in Cruciate-Retaining Total Knee Arthroplasty

BACKGROUND

We hypothesized that when the posterior cruciate ligament (PCL) is found deficient at total knee arthroplasty (TKA), using an anterior-stabilized (AS) tibial insert would provide similar function and survivorship when compared to using a more traditional cruciate-retaining (CR) bearing when the (PCL) is balanced.

METHODS

A total of 1731 TKAs were performed using the same TKA design. Of them, 868 TKAs had a standard CR insert implanted (CR-S), 480 TKAs used a lipped CR insert (CR-L), and 383 TKAs used an AS insert. If the PCL was considered nonfunctional or absent, an AS bearing was placed. When the PCL was balanced, a CR-S or CR-L bearing was used. Follow-up was performed using the Knee Society scoring system. Kaplan-Meier survivorship was used with failure defined as aseptic loosening.

RESULTS

At final follow-up, there were no significant differences in knee flexion, pain, function, or stair scores. Walking scores were significantly lower in the AS group. Posterior instability was higher in the CR-S group, whereas the manipulation rate was highest in the CR-L group (1.7%, 1.3%, and 0% for CR-L, CR-S, and AS groups, respectively). Kaplan-Meier survivorship at 5 years demonstrated no significant difference between the 3 groups (99% 100%, and 99% for CR-S, CR-L, and AS groups, respectively).

CONCLUSION

Using an AS insert provided similar function and 5-year survivorship as compared to using a CR-S and CR-L tibial insert when the PCL was balanced. Using an ultracongruent AS dished tibial component appears to be a reasonable option when the PCL is completely released or found deficient at operation.

The reliability and reproducibility of sagittal spinal curvature measurement using the Microsoft Kinect V2

BACKGROUND

Abnormal sagittal spinal curvature is associated with pain, decreased mobility, respiratory problems and increased mortality. Time-of-flight technology of the Microsoft Kinect sensor can reconstruct a three-dimensional image of the back quickly and inexpensively.

OBJECTIVE

To estimate the extent of the reproducibility of sagittal spine curvature measurement using the Microsoft Kinect sensor.

METHODS

Simultaneous measurement of thoracic and lumbar spine using the Microsoft Kinect sensor in 37 participants. Two investigators gave standardised instructions and each captured 3 images. Thoracic kyphosis and lumbar lordosis angle indexes were calculated using maximum height divided by the length.

RESULTS

Adult participants (mean age in years (SD) = 51.7 (20.6); 57% female; BMI in kg/m2 (SD) = 24.9 (3.3)) kyphosis and lordosis indexes showed high intra-rater and inter-rater ICC values (0.960-0.973). The means of the first images from both raters had significantly larger kyphosis indexes compared to the second and third images, yet no difference between means in lordosis data.

CONCLUSIONS

The results indicate that the Microsoft Kinect sensor has a reproducible method with high intra-rater and inter-rater reliability. The difference between the means over repeated measures suggest the second image capture is more consistent. It is a reproducible and quick method in clinical and research settings.

Arthroscopic Assessment of Syndesmotic Instability in the Sagittal Plane in a Cadaveric Model

BACKGROUND

Syndesmotic instability is multidirectional, occurring in the coronal, sagittal, and rotational planes. Despite the multitude of studies examining such instability in the coronal plane, other studies have highlighted that syndesmotic instability may instead be more evident in the sagittal plane. The aim of this study was to arthroscopically assess the degree of syndesmotic ligamentous injury necessary to precipitate fibular translation in the sagittal plane.

METHODS

Twenty-one above-knee cadaveric specimens underwent arthroscopic evaluation of the syndesmosis, first with all syndesmotic and ankle ligaments intact and subsequently with sequential sectioning of the anterior inferior tibiofibular ligament (AITFL), the interosseous ligament (IOL), the posterior inferior tibiofibular ligament (PITFL), and deltoid ligament (DL). In all scenarios, an anterior to posterior (AP) and a posterior to anterior (PA) fibular translation test were performed under a 100-N applied force. AP and PA sagittal plane translation of the distal fibula relative to the fixed tibial incisura was arthroscopically measured.

RESULTS

Compared with the intact ligamentous state, there was no difference in sagittal fibular translation when only 1 or 2 ligaments were transected. After transection of all the syndesmotic ligaments (AITFL, IOL, and PITFL) or after partial transection of the syndesmotic ligaments (AITFL, IOL) alongside the DL, fibular translation in the sagittal plane significantly increased as compared with the intact state (P values ranging from .041 to <.001). The optimal cutoff point to distinguish stable from unstable injuries was equal to 2 mm of fibular translation for the total sum of AP and PA translation (sensitivity 77.5%; specificity 88.9%).

CONCLUSION

Syndesmotic instability appears in the sagittal plane after injury to all 3 syndesmotic ligaments or after partial syndesmotic injury with concomitant deltoid ligament injury in this cadaveric model. The optimal cutoff point to arthroscopically distinguish stable from unstable injuries was 2 mm of total fibular translation.

CLINICAL RELEVANCE

These data can help surgeons arthroscopically distinguish between stable syndesmotic injuries and unstable ones that require syndesmotic stabilization.

Definition of a Novel Proximal Femur Classification in the Sagittal Plane According to the Femur Morphometric Analysis

BACKGROUND

Studies on prosthesis positioning and implant design in total hip arthroplasty (THA) have generally focused on the anatomy of the proximal femur in the coronal plane. The aim of this study was to investigate the proximal femur morphology in the sagittal plane to provide better positioning of the femoral component in THA and contribute to the determination of proximal femur morphology through possible outcomes that can be shown also by considering the sagittal plane in the selection and design of the femoral component.

METHODS

Computerized tomography scans were obtained from 270 femoral bones belonging to adult skeletons, followed by 3D reconstruction using Leonardo Dr/Dsa Va30a software (Siemens, Erlangen, Germany) and measurements. Canal widths were measured in the coronal and sagittal planes at the lesser trochanter (LT) level, at 20 millimeters proximal to the LT(LT+20) and at various levels distal to the lesser trochanter in 25 mm jumps up to 200 mm from the lesser trochanter.

RESULTS

The average width was wider at the level of the lesser trochanter and all points distal to it in the sagittal plane compared to the coronal plane except LT-200 mm. At each levels from LT-25 to LT-175, the differences were statistically significant (P < .05). The ratio of the femoral width at the lesser trochanter level to the width 50 mm distal to the LT was stated as the most prevalent one, and a novel classification in the sagittal plane was developed in accordance with these findings.

CONCLUSION

A novel and simple classification in the sagittal plane was developed based on the findings of this study, and this classification may improve the accuracy, validity, and reliability of femoral stem fixation in total hip arthroplasty.

Analysis of Radiographic Parameters of Sagittal Spinopelvic Alignment: Polish Nomenclature and Clinical Implications

Over the last 30 years, many authors have suggested that the shape of the human spine in the sagittal plane is helpful in understanding its physiology and pathology. This paper presents the current views and Polish no-men-clature used for the assessment of the morphology and position of the pelvis in the sagittal plane. The va-lues of particular radiographic parameters are presented for healthy individuals and for patients with selected spinal pathologies. Moreover, the paper discusses the practical application of the radiographic parameters that describe the shape and position of the pelvis in the sagittal plane.

Energy dissipation differs between females with and without chronic ankle instability

Chronic ankle instability (CAI) is associated with altered energy dissipation patterns, but comparisons to lateral ankle sprain (LAS) copers have not been explored. The purpose of this study was to examine differences in relative sagittal plane energy dissipation during a single-leg landing between female CAI and LAS coper participants. We separated 33 females (23.6 ± 4.6 years, 164.3 ± 6.2 cm, 69.4 ± 13.7 kg) into CAI (n = 17) and LAS coper (n = 16) groups. Participants completed 5 single-leg landings followed by a 5-second stabilization. We collected sagittal plane kinematics and joint moments at the ankle, knee, hip, and proximal joints (knee and hip) combined then calculated each joint's energy dissipation at 50, 100, 150, and 200 ms post-landing. We compared the percentage of total energy dissipated by the ankle, knee, hip, and proximal joints during each interval utilizing independent t tests and Cohen's d effect sizes. Statistical significance was set a priori at P < .05. The CAI group had lower relative energy dissipation from the ankle at 50 (24.7 ± 11.5% vs 39.2 ± 11.8%, P < .01, d = 1.25 [0.47, 1.95]), 100 (66.9 ± 19.4% vs 77.7 ± 6.5%, P = .04, d = 0.74 [0.01, 1.42]), and 150 ms (70.7 ± 17.8% vs 81.0 ± 5.7%, P = .03, d = 0.77 [0.04, 1.46]) compared to LAS copers. The CAI group had a greater hip contribution through 150 ms (17.9 ± 10.7% vs 11.7 ± 4.4%, P = .04, d =-0.75 [-1.44, -0.03]) and the proximal joints at 50 (75.3 ± 11.5% vs 60.8 ± 11.8%, P < .01, d = -1.25 [-1.96, -0.47]), 100 (33.1 ± 19.4% vs 22.3 ± 6.5%, P = .04, d = -0.74 [-1.42, -0.01]), and 150 ms (29.3 ± 17.8 vs 19.0 ± 5.7%, P = .03, d =-0.77 [-1.46, -0.04]) compared to LAS copers. Females with CAI may benefit from therapeutic exercises designed to correct a single-leg energy dissipation strategy that relies less on the ankle joint.

Changes in mandibular border movements in adult patients after correction of functional anterior crossbite

Background/purpose

An effective approach for assessing masticatory function is necessary. The goal of this study was to establish an efficient method for evaluating mandibular border movements in patients after functional anterior crossbite was corrected.

Materials and methods

Five patients with functional anterior crossbite were included in this study. They were treated with edgewise appliance and improved super-elastic nickel–titanium archwire. The digital images were collected before and after anterior crossbite was corrected. The trajectory paths of mandibular border movement were evaluated on both the frontal and sagittal planes.

Results

When the mandibular border movement paths were analyzed on the frontal plane for the vertical displacement, significant increases in the maximum left- and right-lateral movements were observed. For the horizontal displacement, although decreasing trends were observed in the maximum mouth opening and protrusive movements, no significant difference was detected. However, horizontal displacements were generally greater in men than in women. When the mandibular border movement paths were analyzed on the sagittal plane, significant increases in all the vertical and horizontal displacements were observed at all border movements, except the maximum mouth opening. However, if the data were compared between men and women, significant difference was shown only in the horizontal displacement of the maximum protrusion.

Conclusion

On both the frontal and sagittal planes, after correction of the anterior crossbite there are increases in vertical and horizontal displacements at all kinds of mandibular border movements except for the horizontal displacements at the maximum mouth opening and the maximum protrusion.

The Impact of Total Hip Arthroplasty on Pelvic Motion and Functional Component Position is Highly Variable

BACKGROUND

This study's purpose was to determine the impact of THA implantation on pelvic motion, and to assess motion in patients with a history of lumbar fusion or prosthetic dislocation.

METHODS

This was an IRB-approved, prospective investigation of 3 cohorts: (1) patients without a history of lumbar surgery undergoing THA (group A), (2) patients with a lumbar fusion (group B), and (3) patients with a THA prosthetic dislocation (group C). All patients received both standing and sitting lateral pelvis images to measure sacral slope and pelvic tilt in the sagittal plane.

RESULTS

Fifty-eight patients were enrolled (24 group A, 27 group B, and 7 group C), with no differences in age, gender, or body mass index (P = .1-.7). In group A, the mean change in sacral slope from standing to sitting was 22.1° ± 15.2° preoperatively and 19.5° ± 14.8° postoperatively. However, in 13 patients, the difference in pelvic motion from the standing to seated position, from preoperatively to postoperatively, was >5° and in 10 patients, this difference was >10°. The change in standing to sitting sacral slope was significantly less in patients with a lumbar fusion (9.8° ± 8.2°) and history of prosthetic dislocation (12.5° ± 4.7°) vs group A (P < .001 and P = .008).

CONCLUSION

Implantation of a THA can increase or decrease sagittal plane pelvic motion from the standing to seated position with a high degree of variability. Thus, the ability to predict ideal component positioning from preoperative images may be challenging.

TWO-DIMENSIONAL VIDEO ANALYSIS IS COMPARABLE TO 3D MOTION CAPTURE IN LOWER EXTREMITY MOVEMENT ASSESSMENT

BACKGROUND

Although 3D motion capture is considered the "gold standard" for recording and analyzing kinematics, 2D video analysis may be a more reasonable, inexpensive, and portable option for kinematic assessment during pre-participation screenings. Few studies have compared quantitative measurements of lower extremity functional tasks between 2D and 3D.

PURPOSE

To compare kinematic measurements of the trunk and lower extremity in the frontal and sagittal planes between 2D video camera and 3D motion capture analyses obtained concurrently during a SLS.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twenty-six healthy, recreationally active adults volunteered to participate. Participants performed three trials of the single leg squat on each limb, which were recorded simultaneously by three 2D video cameras and a 3D motion capture system. Dependent variables analyzed were joint displacement at the trunk, hip, knee, and ankle in the frontal and sagittal planes during the task compared to single leg quiet standing.

RESULTS

Dependent variables exhibited moderate to strong correlations between the two measures in the sagittal plane (r = 0.51-.093), and a poor correlation at the knee in the frontal plane (r = 0.308) at (p ≤ 0.05) All other dependent variables revealed non-significant results between the two measures. Bland-Altman plots revealed strong agreement in the average mean difference in the amount of joint displacement between 2D and 3D in the sagittal plane (trunk = 1.68 º, hip = 2.60 º, knee = 0.74 º, and ankle = 3.12 º). Agreement in the frontal plane was good (trunk = 7.92 °, hip = -8.72 º, knee = -6.62 º, and ankle = 3.03 °).

CONCLUSION

Moderate to strong relationships were observed between 2D video camera and 3D motion capture analyses at all joints in the sagittal plane, and the average mean difference was comparable to the standard error of measure with goniometry. The results suggest that despite the lack of precision and ability to capture rotations, 2D measurements may provide a pragmatic method of evaluating sagittal plane joint displacement for assessing gross movement displacement and therein risk of lower extremity injury.

LEVEL OF EVIDENCE

3.

Analysis of the Pelvic Functional Orientation in the Sagittal Plane: A Radiographic Study With EOS 2D/3D Technology

BACKGROUND

We investigated the relationship between pelvic incidence (PI) with anterior pelvic plane angle (APPA), pelvic tilt (PT) angle, and sacral slope (SS) in standing and sitting positions to identify the best parameter expressing the pelvic functional orientation in the sagittal plane.

METHODS

We enrolled 109 consecutive patients (M:F = 43:66) eligible for a primary total hip arthroplasty (THA) with an average age of 63.4 years (15-85). EOS 2D/3D radiography was performed in standing and sitting positions before THA to evaluate the functional pelvic orientation. 3D images took into account the patient-specific sagittal balance measuring APPA, PT, SS, and PI.

RESULTS

In standing position, functional parameters measured 5° ± 7.1 for APPA, 11° ± 8.3 for PT, 43° ± 8.5 for SS, and 53° ± 10.9 for PI. In sitting position, they were -18° ± 10.4 for APPA, 34° ± 11.8 for PT, 20° ± 12.6 for SS, and 54° ± 10.9 for PI. There was no significant difference between men and women in terms of the functional parameters in both positions. No relationship was found between APPA and PI in both positions. SS correlated with PI in standing (r = 0.66; P < .0001; R² = 0.44) and sitting (r = 0.51; P < .0001; R² = 0.26). PT correlated with PI in standing (r = 0.65; P < .0001; R² = 0.42) and sitting (r = 0.38; P < .0001; R² = 0.14).

CONCLUSION

SS shows the highest correlation with functional pelvic tilt. The study suggests that adjustments in acetabular anteversion during primary THA should be based on SS.

Anatomical Calibration through Post-Processing of Standard Motion Tests Data

The inertial measurement unit is popularly used as a wearable and flexible tool for human motion tracking. Sensor-to-body alignment, or anatomical calibration (AC), is fundamental to improve accuracy and reliability. Current AC methods either require extra movements or are limited to specific joints. In this research, the authors propose a novel method to achieve AC from standard motion tests (such as walking, or sit-to-stand), and compare the results with the AC obtained from specially designed movements. The proposed method uses the limited acceleration range on medial-lateral direction, and applies principal component analysis to estimate the sagittal plane, while the vertical direction is estimated from acceleration during quiet stance. The results show a good correlation between the two sets of IMUs placed on frontal/back and lateral sides of head, trunk and lower limbs. Moreover, repeatability and convergence were verified. The AC obtained from sit-to-stand and walking achieved similar results as the movements specifically designed for upper and lower body AC, respectively, except for the feet. Therefore, the experiments without AC performed can be recovered through post-processing on the walking and sit-to-stand data. Moreover, extra movements for AC can be avoided during the experiment and instead achieved through the proposed method.

Failure to restore sagittal tibiotalar alignment in total ankle arthroplasty: Its relationship to the axis of the tibia and the positioning of the talar component

The purpose of this study was to evaluate the change in sagittal tibiotalar alignment after total ankle arthroplasty (TAA) for osteoarthritis and to investigate factors affecting the restoration of alignment. This retrospective study included 119 patients (120 ankles) who underwent three component TAA using the Hintegra prosthesis. A total of 63 ankles had anterior displacement of the talus before surgery (group A), 49 had alignment in the normal range (group B), and eight had posterior displacement of the talus (group C). Ankles in group A were further sub-divided into those in whom normal alignment was restored following TAA (41 ankles) and those with persistent displacement (22 ankles). Radiographic and clinical results were assessed. Pre-operatively, the alignment in group A was significantly more varus than that in group B, and the posterior slope of the tibial plafond was greater (p < 0.01 in both cases). The posterior slope of the tibial component was strongly associated with restoration of alignment: ankles in which the alignment was restored had significantly less posterior slope (p < 0.001). An anteriorly translated talus was restored to a normal position after TAA in most patients. We suggest that surgeons performing TAA using the Hintegra prosthesis should aim to insert the tibial component at close to 90° relative to the axis of the tibia, hence reducing posterior soft-tissue tension and allowing restoration of normal tibiotalar alignment following surgery.

Transabdominal Insonation of Fetal Basilar Artery: A Feasibility Study

BACKGROUND

Fetal anterior, middle, and posterior cerebral arteries have been studied using transabdominal Doppler ultrasound. We performed a feasibility study to determine whether basilar artery can be identified and blood flow velocities measured using transabdominal fetal Doppler ultrasound.

METHODS

The basilar artery was identified in sagittal plane behind the clivus bone using directional color Doppler with 6-2 and 7-4 MHz curved array probes. The clivus was identified by hyperechoic linear signal anterior to junction of vertebral processes and occipital bone and superior to first vertebral body. The flow direction was away from the probe in the basilar artery consistent with caudo cephalic orientation. The Doppler ultrasound probe was placed at insonation angles of less than 30° at the visualized segment of the basilar artery. Peak systolic and end diastolic velocities were measured.

RESULTS

We attempted insonation of the basilar artery in 20 fetuses. The basilar artery was adequately insonated in 18 fetuses with a mean gestational age of 27 weeks (range 19 to 38 weeks). The mean value (±SD) of peak systolic velocity of the basilar artery was 22.1 ± 8.5 cm/second (range 10.4-36.7 cm/second). The mean value (±SD) of end diastolic velocity was 6.8 ± 2.8 cm/second (range 3.5-13.5 cm/second). There was an increase in peak systolic velocity values according to gestational age of fetus.

CONCLUSIONS

We demonstrate the feasibility of fetal basilar artery insonation using directional color Doppler ultrasound via transabdominal approach.

Acoustic and non-acoustic factors in modeling listener-specific performance of sagittal-plane sound localization

The ability of sound-source localization in sagittal planes (along the top-down and front-back dimension) varies considerably across listeners. The directional acoustic spectral features, described by head-related transfer functions (HRTFs), also vary considerably across listeners, a consequence of the listener-specific shape of the ears. It is not clear whether the differences in localization ability result from differences in the encoding of directional information provided by the HRTFs, i.e., an acoustic factor, or from differences in auditory processing of those cues (e.g., spectral-shape sensitivity), i.e., non-acoustic factors. We addressed this issue by analyzing the listener-specific localization ability in terms of localization performance. Directional responses to spatially distributed broadband stimuli from 18 listeners were used. A model of sagittal-plane localization was fit individually for each listener by considering the actual localization performance, the listener-specific HRTFs representing the acoustic factor, and an uncertainty parameter representing the non-acoustic factors. The model was configured to simulate the condition of complete calibration of the listener to the tested HRTFs. Listener-specifically calibrated model predictions yielded correlations of, on average, 0.93 with the actual localization performance. Then, the model parameters representing the acoustic and non-acoustic factors were systematically permuted across the listener group. While the permutation of HRTFs affected the localization performance, the permutation of listener-specific uncertainty had a substantially larger impact. Our findings suggest that across-listener variability in sagittal-plane localization ability is only marginally determined by the acoustic factor, i.e., the quality of directional cues found in typical human HRTFs. Rather, the non-acoustic factors, supposed to represent the listeners' efficiency in processing directional cues, appear to be important.