Mediolateral Research Articles

Effects of visual disruption on static and dynamic postural control in people with and without chronic ankle instability

IntroductionChronic Ankle Instability (CAI) is a chronic syndrome resulting from repeated ankle sprains that lead to persistent dysfunction.the purpose of this study is to determine whether visual disruption could influence static and dynamic postural control in people with and without chronic ankle instability (CAI), with the objective of gaining a comprehensive understanding of the interactions between visual inputs and postural control.MethodsThirty people with CAI (21 males and 9 females, age = 22.0 ± 1.8 years, height = 174.4 ± 10.2 cm, body mass = 72.5 ± 15.4 kg; Cumberland Ankle Instability Tool (CAIT) score = 19.7 ± 1.8) and twenty-nine without CAI (24 males and 5 females, age = 22.9 ± 1.6 years, height = 172.8 ± 8.0 cm, body mass = 69.0 ± 11.3 kg; CAIT score = 29.0 ± 0.7) were recruited. Their static and dynamic postural control was measured in two conditions with or without visual disruption, simulated using stroboscopic glasses. Static postural control was measured during single-limb standing and represented by root mean square (RMS) of the plantar center of pressure (CoP), dynamic postural control was measured during a Y-balance test and represented by the relative reach distance. Two-way mixed ANOVA (between group: CAI vs non-CAI, within group: normal vision vs visual disruption) was used to analyze data.Results and discussionSignificant interactions were detected in the CoP-RMS in the anteroposterior (AP) (p = 0.021, η2p = 0.090) and mediolateral (ML) (p < 0.001, η2p = 0.208) directions, and the relative reach distances in the posteromedial (PM) p = 0.023, η2p = 0.088) and posterolateral (PL) (p = 0.009, η2p = 0.113) directions, from normal vision to visual disruption. The CoP-RMS in the AP and ML directions significantly increased and the relative reach distances in the PM and PL directions significantly decreased in people with CAI while remaining unchanged in those without CAI. People with CAI are susceptible to visual disruption on postural control, highlighting the importance of visual input in maintaining stable posture in this population.

The Tibial Tunnel Size Relative to the Proximal Tibia Affects the Tibial Tunnel Widening in Anatomical Anterior Cruciate Ligament Reconstruction.

The impact of the bone tunnel size relative to body size on clinical results in anterior cruciate ligament (ACL) reconstruction remains unclear. This study aimed to assess the morphological alteration of the tibial tunnel aperture and relationship between the tibial tunnel size relative to the proximal tibia among the tibial tunnel widening (TW) and clinical results following ACL reconstruction. This study comprised 131 patients who had undergone anatomical ACL reconstruction utilizing bone-patellar tendon-bone autografts. The morphology and enlargement of the tibial tunnel were examined via three-dimensional computed tomography 1 week and 1 year postoperatively. The anteroposterior (AP) and mediolateral (ML) positions were determined as a percentage relative to the proximal AP and ML tibial dimensions, respectively. Clinical assessment was conducted 2 years postoperatively. The association between the primary tibial tunnel size among TW and clinical outcomes was examined. The tibial tunnel significantly migrated posterolaterally. The ML diameter significantly widened; however, the AP diameter did not exhibit widening. AP widening was associated with the AP diameter of the primary tibial tunnel (r = -0.482, p < 0.01), and ML widening correlated with the ML diameter of that tunnel (r = -0.478, p < 0.01). However, there was no significant correlation observed between the primary tibial tunnel size and clinical outcomes. The tibial tunnel migrated and enlarged laterally in the ML plane, but did not enlarge in the AP plane. The primary tibial tunnel diameter relative to the proximal tibia negatively correlated with the tibial TW in the AP and ML planes. Level of evidence: level IV.

Implications for fall efficacy strategies on center of pressure and center of gravity sway distances in adults with chronic low back pain.

Although chronic low back pain (LBP) is a complex condition often associated with altered motor control and compensatory postural adjustments, existing literature provides inconsistent reports on the underlying control mechanisms for maintaining balance. This study aimed to compare differences in sway distances between the center of pressure (COP) and the center of gravity (COG), while considering limb dominance, in adults with and without LBP. There were 26 subjects with LBP and 39 control subjects who performed three repeated unilateral standing tasks on a force platform. Outcome measures included the sway distances between COP and COG in the anteroposterior (AP) and mediolateral (ML) directions, as well as the results of the fall efficacy scale (FES). A significant group interaction was demonstrated on limb dominance and direction for the sway distance (F = 5.46, p = 0.02). Specifically, the third trial in the ML direction while standing on the dominant limb indicated a significant difference in COP-COG sway distance (t = -2.30, p = 0.01). When FES scores were used as a covariate, a significant three-way interaction (dominance x direction x trial) was found (F = 4.06, p = 0.04). Although no significant group interaction was observed for dominance, direction, and trial, the LBP group demonstrated an ability to leverage fall efficacy following repeated trials to reduce ML balance deficits. Clinicians should consider neuromuscular control and limb dominance when developing fall efficacy strategies for postural adaptations in adults with LBP.

Identification of Essential Features in Developing a Novel Femoral Stem Reflecting Anatomical Features of East Asian Population: A Morphological Study.

Background: Recent advancements in hip arthroplasty aim to enhance the stability, longevity, and functionality of femoral implants. However, the distal fitting of femoral stems, often caused by metaphyseal-diaphyseal mismatch, remains a significant issue, particularly in patients with Dorr type A femora. Such mismatches can result in suboptimal implant performance, leading to potential complications. This study focuses on evaluating the anatomical compatibility of five representative single-tapered wedge mid-short stems with the mediolateral (ML) anatomy of the proximal femur in an East Asian population, where these mismatches are often more pronounced. Methods: A total of 742 patients from two hospitals, all of whom underwent unilateral primary total hip arthroplasty, were included in the study. The contralateral proximal femur was confirmed to have normal anatomy in each patient. Hip anteroposterior radiographs were used for measurements, which were standardized in conjunction with CT images. Key anatomical parameters were measured, including proximal and distal medial-lateral canal dimensions, vertical offset, and medial offset. Five femoral stem designs-Tri-lock®, Taperloc®, Anthology®, Accolade II®, and Fit®-were evaluated. R programming was employed for a detailed fit analysis to match stem sizes with patient anatomy, categorizing the fit as proximal, simultaneous proximal-distal, or distal engagement. Results: Among the femoral stems analyzed, the Fit® stem demonstrated the closest alignment with the regression line for ML widths in the study population (slope = 0.69; population ML slope = 0.38). This was followed by Accolade II®, which had a slope of 0.83. In terms of offset options, the Accolade II® offered the largest offset coverage, making it particularly suitable for this population. The fit analysis revealed that the Fit® stem had the highest suitable fit rate (90.56%), followed by Accolade II® (73.04%). Taperloc®, Anthology®, and Tri-lock® had similar fit rates of approximately 59%. Overall, optimal results were obtained for 92.05% of the population in the automated fitting trial, regardless of the product type. Conclusions: When designing modern cementless femoral stems intended for press-fit fixation, it is crucial to account for the anatomical variations specific to the target population. In this study, Fit® and Accolade II® femoral components demonstrated superior compatibility with the femoral anatomy of the East Asian population, particularly in those with a higher incidence of Dorr type A femora. These stems, characterized by slimmer distal dimensions and high-offset options, appear to minimize metaphyseal-diaphyseal mismatch and associated complications.

Shoulder-assist exoskeleton effects on balance and muscle activity during a block-laying task on a simulated mast climber

Interest in utilizing exoskeletons to mitigate the risks of musculoskeletal disorders (MSDs) among construction workers is growing, spurred by encouraging results in other industries. However, it is crucial to carefully examine their impact on workers' stability and balance before implementation. In this study, seven male participants lifted a 35-lb cinder block from a production table to a simulated wall at two heights—elbow and shoulder levels—using three different exoskeleton models on an unstable platform, where their balance and shoulder muscle activity were assessed. Balance-related parameters, included mean distance (MDIST), total excursion (EXCUR), and mean velocity (VEL) of the center of pressure, were derived from force plate data. Muscle activity in six shoulder and upper arm muscles was estimated using electromyography (EMG) data. The results indicated that wearing two of the exoskeletons significantly increased both total and medio-lateral (ML) MDIST compared to not wearing an exoskeleton. Wearing one of the exoskeletons significantly increased total and ML VEL and ML EXCUR. Although lifting level did not have a significant impact on the balance parameters, it did affect the muscle activity in most of the measured muscles. Moreover, only one exoskeleton significantly reduced the activity in a particular shoulder muscle compared to no exoskeleton use. In conclusion, the evaluated shoulder-assist exoskeletons showed limited benefits for preventing upper extremity MSDs and may negatively affect whole-body balance during a block-laying task on an unstable platform. These findings underscore the importance of comprehensive evaluations of balance and effectiveness prior to adopting exoskeletons in construction.

Risk Factors for High Repair Tension During Rotator Cuff Repair

Background: Excessively high repair tension, especially tension ≥10 N, can lead to unsuccessful rotator cuff repair. Purpose/Hypothesis: The purpose of this study was to identify the preoperative risk factors for high repair tension in rotator cuff repair. It was hypothesized was that older age, longer symptom duration, nontraumatic (ie, degenerative) tear onset, progressive fatty degeneration, and larger tear size would be among the risk factors. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This retrospective study involved 80 patients (80 shoulders) diagnosed with rotator cuff tears by magnetic resonance imaging between July 2018 and August 2020. Repair tension was measured intraoperatively using a digital tension meter. Risk factors for high repair tension (≥10 N) were evaluated. The t test was used to assess the relationship of repair tension with patient characteristics and surgical parameters. Parameters with a P value of &lt;.05 in the univariate analysis were entered into a multivariate logistic regression model to determine their relationship with repair tension ≥10 N. Results: Symptom duration of ≥4 months, nontraumatic tear onset, large/massive tears, mediolateral (ML) tear length of ≥20 mm, and anteroposterior (AP) tear length of ≥18 mm were associated with high odds of repair tension ≥10 N ( P≤ .013 for all). Multivariate analysis showed that nontraumatic onset, ML tear length of ≥20 mm, and AP tear length of ≥18 mm were independent risk factors for repair tension ≥10 N ( P≤ .035 for all). Conclusion: The independent risk factors for high repair tension (≥10 N) during rotator cuff repair were nontraumatic tear onset, ML tear length of ≥20 mm, and AP tear length of ≥18 mm. Symptom duration of ≥4 months and large/massive tears were associated with high odds of repair tension ≥10 N, although they were not considered independent risk factors. Prospective cohort studies with larger sample sizes are needed to confirm the clinical value of the risk factors identified in this study.

Morphological CBCT parameters for an accurate differentiation between nasopalatine duct cyst and the normal nasopalatine canal

BackgroundThe incisive foramen width was a traditional imaging criterion for diagnosing nasopalatine duct (NPD) cysts. Recent CBCT studies demonstrated significant dimensional variations of the nasopalatine canal, which raised questions about the accuracy of this criterion. This study investigated whether nasopalatine canal diameters assessed on CBCT images can accurately differentiate NPD cysts from normal nasopalatine canals.MethodsThe study included 19 patients with NPD cysts (12 (63.2%) males, 7 (36.8%) females, mean age 44.7 ± 13.3), and a control group of 164 patients (72 (43.9%) males, 92 (56.1%) females, mean age 47.25 ± 17.74). CBCT images were retrospectively evaluated. The following nasopalatine canal diameters were measured on reference sagittal, coronal, and axial reformation images: nasal opening anteroposterior (AP) and mediolateral (ML) diameter, oral opening AP (APOO) and ML (MLOO) diameter, nasopalatine canal length, minimum ML (minML) diameter, anterior wall expansion (AWE), nasopalatine canal angle, and the mid-level AP diameter (midAP). All parameters were compared between groups. Discriminant functional analysis (DFA) was applied to detect CBCT parameters that best differentiate the NPD cyst from the normal canal.ResultsPatients with NPD cyst had significantly greater values of APOO (7.06 ± 2.09 vs. 5.61 ± 1.70), MLOO (6.89 ± 2.95 vs. 3.48 ± 1.24), minML (2.88 ± 1.53 vs. 2.25 ± 1.09), AWE (2.15 ± 0.65 vs. 0.41 ± 0.67), and midAP (4.58 ± 1.61 vs. 2.48 ± 0.96). DFA showed MLOO, AWE, and midAP as the most accurate in distinguishing NPD cyst from the normal canal. When combined in the discriminant function equation X = 0.390·MLOO + 1.010·AWE + 0.288·midAP (cut score 1.669), the differentiation can be performed with a sensitivity and specificity of 98.8% and 76.9%, respectively.ConclusionNPD cysts can be accurately distinguished from the normal nasopalatine canal by measuring MLOO, AWE, and midAP diameter on CBCT images.

Strategies for unplanned gait termination at comfortable and fast walking speeds in children with cerebral palsy

Collision avoidance while walking is necessary for safe living, and faster walking speeds tend to increase collision risk. However, gait termination strategies for patients with cerebral palsy (CP), from comfortable to faster speed, remain unexplored. This study aimed to analyze these strategies in children with CP compared to typically developing (TD) children at two different speeds. Study participants included 10 children with CP (mean age, 12.5; five females; mean height, 147.8 cm; mean weight, 41.7 kg) and 10 TD children (mean age, 11.4; nine females; mean height, 142.0 cm; mean weight, 38.1 kg). Effects of walking speed on spatial, force, and temporal parameters were assessed at 100 % (WS1) and 125 % (WS2) speeds of comfortable walking. The TD group exerted a more pronounced braking force at the first step after the stop line appeared on the floor until the contralateral step at both WS1 (P = 0.006) and WS2 (P = 0.019); however, the CP group exerted a more potent force after the second step (WS1: P = 0.026, WS2: P = 0.023) in the anterior-posterior (AP) direction. Additionally, an increase in the center of mass (COM)-center of pressure (COP) divergence in the AP direction (P = 0.032), which decreased in the mediolateral (ML) direction (P = 0.036) at faster walking speeds, influenced the kinetic characteristics of the CP group from WS1 to WS2. The complex adaptations, such as unique braking forces and changes in the COM-COP divergence, suggest that gait interventions should consider the distinctive forces and adopt dynamic balancing strategies to avoid collisions during walking.

Assessment of postural sway with accelerometers: A comparison with force plate measures

Introduction &amp; Purpose Postural control is essential for maintaining balance during static and dynamic tasks. It is typically measured by centre of pressure (CoP) deviations using a ground reaction force plate (FP). Alternatively, more affordable and accessible accelerometer-based measures have been proposed. However, no consensus on the best protocol exists (Pinho et al., 2019). This study investigates the feasibility of assessing postural sway using linear acceleration data, considering sensor placement, task difficulty and analysed parameters. Methods The University of Vienna Ethics Committee approved this study (Ref. Nr. 01108). Ten healthy adults (6 M/4 F; 37.9 ± 14.8 years; BMI = 23.3 ± 2.3) performed eleven balance tasks, seven easy tasks from the Berg Balance Scale and four harder tasks with eyes closed, each lasting 20 seconds. Postural sway was assessed using a FP and five inertial measurement units (IMUs) attached to the upper spine (C7), lower spine (L1), sacrum and both thighs. Data were synchronously collected at 1500 Hz, zeroed, band pass filtered (3rd order Butterworth, 0.3-10 Hz; Martinez-Mendez et al., 2012), and cropped to 19 s. Outcomes included CoP path length, root mean square of sway amplitude in the anteroposterior (AP) and mediolateral (ML) directions for the FP, and RMS of the linear acceleration in AP and ML directions, along with their sum, for the ACC. Combinations of the two AP, two ML and two overall parameters were analysed by winsorised Pearson correlations and Bland Altman limits of agreement of z-scores for each task and for each sensor site. Fisher's Z-transformed correlation coefficients and limits of agreement were compared across task difficulty, parameter combinations, and sensor placement sites using a 3-way ANOVA. Results Pearson coefficients correlating the ACC parameters with the FP parameters averaged 0.60 (95% CI [0.54, 0.66]) for the easy tasks and 0.78 (95% CI [0.726, 0.84]) for the hard tasks, with no significant differences between sensor sites. A significant interaction (p &lt; 0.001) was found between task difficulty and parameter combination. Simple main effect analysis showed no difference between correlations of AP, ML and overall parameters for hard tasks but for easy tasks, where overall parameters showed the highest correlation, followed by ML and then AP parameters, all differing significantly from each other. The Bland Altman mean difference of z-scores between FP and ACC parameters was on average -0.002 (95% CI [-0.027, 0.024]). The lower and upper limits of agreement were on average -0.72 (95% CI [-0.84, -0.62]) and 0.73 (95% CI [0.62, 0.83]) respectively. Discussion The correlations between FP and ACC were higher during more challenging tasks, while the limits of agreement were broader and less precise in these tasks (data not shown). No optimal sensor placement site was identified as correlation and agreement between the two methods did not differ significantly between sites. The broad limits of agreement suggest relatively low precision of ACC measures compared to FP. Overall parameters often outperformed ML and AP parameters in terms of correlation and precision. Conclusion Accelerometer-based measures of postural sway showed high correlations with force plate measures but low precision when tasks where difficult enough to challenge participants’ balance. Sensor placement site did not influence correlation and precision. References Pinho, A. S., Salazar, A. P., Hennig, E. M., Spessato, B. C., Domingo, A., &amp; Pagnussat, A. S. (2019). Can we rely on mobile devices and other gadgets to assess the postural balance of healthy individuals? A systematic review. Sensors, 19(13), Article 13. https://doi.org/10.3390/s19132972 Martinez-Mendez, R., Sekine, M., &amp; Tamura, T. (2012). Postural sway parameters using a triaxial accelerometer: Comparing elderly and young healthy adults. Computer Methods in Biomechanics and Biomedical Engineering, 15(9), 899–910. https://doi.org/10.1080/10255842.2011.565753

Physiological complexity of body sway during dual-task gait in faller older adults

Background: The impact of simultaneous cognitive demand on gait’s physiological complexity in community-dwelling older adults with and without self-reported falls is yet unknown. Objective: To analyze whether the physiological complexity of body sway during dual-task and single gait is worse in once-only fallers than in non-faller older adults. Methods: A total of 58 community-dwelling older adults aged 60 to 80 participated in this study, of whom 21 had self-reported a single fall in the previous 12 months (fallers) and 37 matched participants with no fall self-reported (non-fallers). An inertial sensor (Physilog® 5, Gait Up, Switzerland) was used to acquire the time series of the body center of mass (CoM) sway in the anteroposterior (AP), mediolateral (ML) and vertical (V) directions during single gait (ST) and the gait under dual task (DT). The composite refined multiscale fuzzy entropy method was used to calculate the physiological complexity index (CI) in a MATLAB environment. SPSS (IBM; v.25.0) was used to analyze the effects of group (Fallers vs. Non-fallers), condition (ST vs. DT), and interaction (group vs. condition), using generalized linear mixed models, with an alpha of 5%. Results: No interaction or group effect was observed for the CI. However, when comparing DT with ST, a main effect of the condition was observed for the AP direction (F = 62.394; p &lt; .001) with a reduction of 0.53 (95% CI: -0.66 to -0.39), ML (F = 4.724; p = .034) with an increase of 0.22 (95% CI: 0.17 to 0.42), and V (F = 6.457; p = .014) with a decrease of 0.17. Conclusion: Just one fall in the previous 12 months does not deleteriously influence the body’s physiological complexity during gait under concurrent cognitive demand (dual task). On the other hand, DT significantly affects the gait physiological complexity in community-dwelling older adults.

The Effect of Different Sensory Perturbations on Postural Control and Fall Risk in Benign Paroxysmal Positional Vertigo Patients.

Benign paroxysmal positional vertigo (BPPV) patients may experience balance problems in various environmental conditions other than positional dizziness. Therefore, there is a need to investigate the postural control abilities and the ability to use sensory inputs in BPPV patients in different conditions. The aim of this study was to examine the postural control performance of middle-aged adult BPPV patients in easy and difficult balance tasks, the effect of vestibular stimulation on the maintenance of balance, and the risk of falling, by posturographic evaluation in various conditions. A total of 26 patients diagnosed with posterior canal BPPV and 26 controls were included in the study. Sensory Organization Test (SOT), Vestibular Stimulation Test (VST), and fall risk assessment (FRA) were applied to the participants, respectively. Significant difference was observed in SOT medio-lateral (ML) plane in Conditions 2 and 5 (p < .05). A significant difference was observed in the vestibular score in the SOT ML plane. No significant difference was observed in VST test scores (p > .05). In the FRA test, a significant difference was observed in the energy and gain parameters in the anterio-posterior plane (p < .05). The current study examined postural control abilities of patients with BPPV in extensive external conditions and in both planes, using various sensory perturbations and stimulation. It was thought that while BPPV patients were in the active phase of the disease, their postural control skills in the ML plane decreased and they might be at risk of falling.

Does selective attention demand affect the physiological complexity of postural control in faller community-dwelling older adults?

Background: The physiological complexity of postural control during selective attention demand can be used as an innovative method to identify faller community-dwelling older. Objective: To analyze the effect of selective attention on the complexity of postural control in faller community-dwelling older adults. Methods: A total of 57 older adults (60 to 80 years) were divided between the faller group (Fallers n = 21) and the non-faller group (Non-fallers n = 36). An inertial sensor (Physilog® 5, GaitUp, Switzerland) was positioned over the second sacral vertebra to collect the participant’s body sway in the anteroposterior (AP) and mediolateral (ML) directions during the monochromatic and color Stroop test versions. The postural control’s complexity was calculated using MATLAB codes, employing the refined composite multiscale fuzzy entropy method. Statistical Package for Social Sciences was used to analyze the effects of interaction, group, and condition effects using linear mixed models with an alpha of 5%. Results: No significant interaction effects were observed in the AP (F = 0.18; p = 0.66) and ML (F = 0.00; p = 0.99) directions. No group effect was observed in the AP (F = 1.23; p = 0.26) and ML (F = 1.76; p = 0.18) directions. No condition effect was found in the AP (F = 0.06; p = 0.80) and ML (F = 3.54; p = 0.06) directions. Conclusion: Once-only faller community-dwelling older adults did not evidence worse physiological complexity than the non-fallers during selective attention demand in the upright standing posture.

Validation of a micro-doppler radar for measuring gait modifications during multidirectional visual perturbations

BackgroundChanges in spatio-temporal gait parameters and their variability during balance-challenging tasks are markers of motor performance linked to fall risk. Radio frequency (RF) sensors hold great promise towards achieving continuous remote monitoring of these parameters. Research questionsTo establish the concurrent validity of RF-based gait metrics extracted using micro-Doppler (µD) signatures and to determine whether these metrics are sensitive to gait modifications created by multidirectional visual perturbations. MethodsFifteen participants walked overground in a virtual environment (VE) and VE with medio-lateral (ML) and antero-posterior (AP) perturbations. An optoelectronic motion capture system and one RF sensor were used to extract the linear velocity of the trunk and estimate step time (ST), step velocity (SV), step length (SL), and their variability (STV, SVV, and SLV). Intra-class coefficient for consistency (ICC), mean and standard deviation of the differences (MD), 95 % limits of agreement, and Pearson correlation coefficients (r) were used to determine concurrent validity. One-way repeated-measures analysis of variance was used to analyze the main and interaction effects of visual conditions. ResultsAll outcomes showed good to excellent reliability (r>0.795, ICC>0.886). Average gait parameters showed good to excellent agreement, with values obtained with the RF sensor systematically smaller than the values obtained with the markers (MD of 0.001 s, 0.09 m/s, and 0.06 m). Gait variability parameters showed poor to moderate agreement, with values obtained with the RF sensor systematically larger than those obtained with the markers (MD of 1.9 %-3.9 %). Both measurement systems reported decreased SL and SV during ML perturbations, but the gait variability parameters extracted with the radar were not able to detect the higher STV and SLV during this condition. SignificanceThe radar µD signature is a valid and reliable method for the assessment of average spatio-temporal gait parameters but gait variability measures need to be viewed with caution because of the lower levels of agreement and sensitivity to ML visual perturbations. This work represents an initial investigation for the development of a low-cost system that will facilitate aging-in-place by providing remote monitoring of gait in natural settings.

Effects of attentional focus on quiet standing balance control in individuals with non-specific chronic low back pain

Despite the widespread research about the effects of attentional focus on balance control in different populations, to the best of our knowledge, no study has yet investigated the effects of attentional focus instructions on balance control in individuals with chronic low back pain (CLBP). Therefore, this study was aimed to compare the effects of internal focus (IF) and external focus (EF) of attention on quiet standing balance control between individuals with CLBP and healthy controls. Twenty individuals with CLBP and 20 healthy controls were enrolled in this quasi-experimental study. The participants were asked to stand still with eyes open and eyes closed while performing three tasks: baseline standing with no focus instructions, internally focusing on their feet, and externally focusing on two markers were placed on the force platform. Statistical analyses showed a significant main effect of group for mean total velocity (p = 0.02), area (p = 0.01), and displacement in mediolateral (ML) direction (p = 0.003). Moreover, a significant main effect of vision was observed for mean total velocity (p < 0.001), area (p < 0.001), and displacement in anteroposterior (AP) (p < 0.001) and ML directions (p < 0.001). Also, the results revealed a significant main effect of attentional focus for mean total velocity (p < 0.001), area (p < 0.001), and displacement in AP (p < 0.001) and ML directions (p = 0.01). Our results showed that in both healthy controls and individuals with CLBP, EF led to improve quiet standing balance control compared to IF and control conditions. From a clinical perspective, it may be useful for physical therapists to consider the use of instruction cues that direct performer's attention away from the body for improving quiet standing balance control in individuals with CLBP.

Morphological Measurement and Clinical Significance of Abnormal Development of Distal Femur with Hemophilia Knee Arthritis: A Consideration on the Renewal of Total Knee Prosthesis.

The knee joint of hemophiliacs may face the result of local morphological changes due to long-term irritation of synovitis. This study aims to elucidate the morphological characteristics of distal femur in hemophilic arthritis (HA) and compare the compatibility of three types of prostheses with the anteroposterior (AP) and mediolateral (ML) dimensions of the femoral osteotomy surface. This study retrospectively and randomly selected 50 patients with HA registered for treatment at our hospital from June 2016 to August 2022 as the study subjects, with an equal number of male osteoarthritis (OA) patients and healthy male individuals set as the control group. This study used medical digitalization software to simulate osteotomies on the distal femur during total knee arthroplasties (TKA) for 50 patients with HA, OA patients, and the healthy population, respectively, and measure the morphological parameters to compare with three commonly used femoral components of TKA in clinical practice. The differences between the femur resection of anteroposterior and mediolateral (FRAP, FRML) osteotomy surface and the prosthesis's BOX-AP/ML were compared in three prostheses. One-way ANOVA and multiple Kruskal-Wallis H test were used for the normal or non-normal distribution data, and pairwise comparisons between groups were conducted using the Bonferroni method, and the linear correlation analysis was utilized to assess the relationship between section femoral morphological data and prosthesis parameters. In HA patients, the morphological characteristics of the distal femur were shown as shorter than femur AP (FAP), medial and lateral condyle anterior-posterior dimension (FMCAP, FLCAP), notch width (NW), posterolateral condyle height (PLCH), posteromedial condyle width (PMCW), and posterior condylar axis length (PCAL) dimension. They had comparatively smaller femur section aspect ratios (p < 0.005). They showed longer posterolateral condyle width (PLCW), anterior condyle mediolateral dimension (FRACML), anterolateral condyle height (ALCH), and femur resection anterior condylar mediolateral (FRACML) dimension (p < 0.005). They showed larger distal femur aspect ratio and resection aspect ratio (FAR, FRAR, p < 0.005). All selected prostheses showed ML undercoverage under similar AP dimensions, and ML undersizing of Attune systems was more obvious in three femoral prostheses. The distal femur morphological change of HA patient is shown as smaller AP dimension, narrow posterior condyle spacing, lower and shallower trochlear, thinner anterior condyle, wider and lower intercondylar notch and higher posterior-lateral condyle. The selected prostheses showed ML undercoverage under similar AP dimensions. This typical morphological tendency of the distal femur seems to warrant consideration in the process of knee joint prosthesis upgrading.

Impact of human micro-movements on breathing zone and thermal plume formation

To enhance the realism and precision of indoor environment assessments and the evaluation of human health risks using computational fluid dynamics (CFD), it is crucial to accurately replicate human shape and physiological functions. This study investigates the influence of micro-movements resulting from posture control on the human breathing zone (BZ) using CFD analysis. A Computer-Simulated Person (CSP) incorporating a sophisticated nasal cavity model and multi-node thermoregulation was employed to precisely predict the microclimate around the human body, including the BZ. Two types of movements were considered to replicate micro-movements of a standing human body: angular and linear movements. The BZs were evaluated based on the Scale for Ventilation Efficiency (SVE) 4 and 5 for exhalation and inhalation modes, respectively. While the distribution of exhaled air remained generally consistent, distinct differences were observed in inhaled air distribution. In a representative case with a maximum angular velocity of 4°/s, the horizontal length increased by 12 cm, and the vertical distance of the SVE5>10 % distribution decreased by 14 cm compared to the stationary case. Linear movement, particularly in the mediolateral (ML) direction, led to a horizontal expansion of the inhaled air distribution. The findings of this study suggest that replicating human micro-movements has a minimal impact on general indoor climate analysis but significantly enhances the accuracy of predicting breathing air quality.

Improved Acromiohumeral Distance Independently Predicts Better Outcomes After Arthroscopic Superior Capsular Reconstruction Graft Tears

PurposeTo identify independent factors responsible for the poor outcomes after a graft tear after arthroscopic superior capsular reconstruction (ASCR). MethodsPatients who underwent ASCR for massive rotator cuff tears between January 2013 and July 2021were reviewed. Based on the achievement of the minimal clinically important differences for clinical outcome measures at the final follow up, patients were divided into the good outcome (GO) and poor outcome (PO) groups. The minimal clinically important differences were calculated as the values equal to one‐half of the standard deviation of the changes in outcome scores between the preoperative baseline and the latest follow‐up. Pre- and final follow-up variables included demographics, American Shoulder and Elbow Surgeons (ASES) score, Constant score, visual analog scale (VAS) score, range of motion, Preoperative and postoperative 1-year radiological variables were analyzed using MRIs, including anteroposterior (AP) and mediolateral (ML) tear sizes, subscapularis tear, acromiohumeral distance (AHD), and degree of fatty degeneration. Logistic regression analysis was performed to identify the significant predictors of poor outcomes. ResultsA total of 33 patients who underwent ASCR presented with graft tears, which were confirmed by postoperative 1-year magnetic resonance imaging (MRI), and had a minimum follow-up duration of 2 years after surgery were enrolled. The GO group demonstrated significantly greater improvements in functional outcomes compared with the PO group (ASES: 83.5 ± 11.8 vs. 64.0 ± 20.4, P = 0.004; Constant: 67.6 ± 5.7 vs. 57.1 ± 9.8, P <0.001; and VAS: 0.9 ± 1.2 vs. 2.4 ± 2.0, P = 0.026). The postoperative 1-year AHD showed significant improvement in the GO group (3.1 ± 1.2 vs. 6.1 ± 1.4, P <0.001) but no change in the PO group (3.4 ± 1.3 vs. 4.2 ± 0.9, P = 0.074) postoperatively. Multivariate logistic regression analysis indicated that a decreased postoperative 1-year AHD (OR, 0.145; P = 0.019) was associated with a poor outcome after a graft tear. ConclusionA narrow postoperative 1-year AHD was identified as the most importantindependent risk factor indicating poor clinical outcomes after a graft tear post-ASCR, which was related to a larger tear and loss of integrity between the grafts and infraspinatus at 1 year postoperatively. Level of evidenceLevel IV.

Center of Pressure Measurement Accuracy via Insoles with a Reduced Pressure Sensor Number during Gaits.

The objective was to compare simplified pressure insoles integrating different sensor numbers and to identify a promising range of sensor numbers for accurate center of pressure (CoP) measurement. Twelve participants wore a 99-sensor Pedar-X insole (100 Hz) during walking, jogging, and running. Eight simplified layouts were simulated, integrating 3-17 sensors. Concordance correlation coefficients (CCC) and root mean square errors (RMSE) between the original and simplified layouts were calculated for time-series mediolateral (ML) and anteroposterior (AP) CoP. Differences between layouts and between gait types were assessed via ANOVA and Friedman test. Concordance between the original and simplified layouts varied across layouts and gaits (CCC: 0.43-0.98; χ(7)2 ≥ 34.94, p < 0.001). RMSEML and RMSEAP [mm], respectively, were smaller in jogging (5 ± 2, 15 ± 9) than in walking (8 ± 2, 22 ± 4) and running (7 ± 4, 20 ± 7) (ηp2: 0.70-0.83, p < 0.05). Only layouts with 11+ sensors achieved CCC ≥ 0.80 in all tests across gaits. The 13-sensor layout achieved CCC ≥ 0.95 with 95% confidence, representing the most promising compromise between sensor number and CoP accuracy. Future research may refine sensor placement, suggesting the use of 11-13 sensors. For coaches, therapists, and applied sports scientists, caution is recommended when using insoles with nine or fewer sensors. Consulting task-specific validation results for the intended products is advisable.

Smartphone Usage and Postural Stability in Individuals With Forward Head Posture: A Nintendo Wii Balance Board Analysis.

To assess postural stability, specifically center of body sway during single-leg standing balance, among individuals with and without forward head posture (FHP) during smartphone use. The research recruited 53 healthy smartphone users, aged 18-25, and categorized them into FHP group comprising 26 subjects and the normal (control) group with 27 subjects. Participants were assigned the task of maintaining balance while engaged in smartphone typing during single-leg standing. The experiment involved four specific conditions according to neck posture and stable of surface. The study meticulously quantified body center of pressure (COP) sway amplitudes using the Nintendo Wii Balance Board. The research revealed that individuals with FHP exhibited significantly greater body sway compared to the control group when using smartphones. Notably, distinct variations were observed in path length sway, anteroposterior (AP), and mediolateral (ML) sway amplitude, particularly evident when maintaining flexed neck positions on a soft surface while engaged with smartphones. These findings strongly suggest that individuals with FHP encounter deteriorated postural stability during smartphone use, particularly in challenging head positions.

Effects of Chronic Pain on Static and Dynamic Postural Control in Chronic Ankle Instability.

To identify the effects of chronic pain levels on static and dynamic postural (DP) control in individuals with chronic ankle instability (CAI). Cross-sectional study. Controlled laboratory. Sixty participants were divided into the following 3 groups: 20 high pain individuals with CAI (high pain), 20 low pain individuals with CAI (low pain), and 20 healthy controls (control). Groups (CAI with high pain, CAI with low pain, and control) and visual conditions (eyes open and closed) for single-leg stance. Participants performed single-leg stance with eyes open and closed, the star excursion balance test, and single-leg hop to stabilization. The high pain group experienced worse self-reported outcomes, including Foot and Ankle Ability Measure activities of daily living and sports, than the low pain and control groups. Regardless of visual condition, both the high and low pain groups exhibited decreased static postural control in mediolateral (ML) compared with the control group. Specifically, the high pain group showed decreased static postural control in ML under closed eyes compared with the low pain and the control groups. The high pain group showed less reach distance than the control group and increased DP control in vertical and overall DP stability index compared with the low and control groups. Chronic pain can significantly affect both static and DP control in individuals with CAI. Therefore, clinicians should consider chronic pain as one of the factors affecting postural control in individuals with CAI.