In vivo movement interrelationships among the medial meniscus, joint capsule, and semimembranosus during tibial rotation.

The meniscal position within the knee is critical to maintain normal knee function. The joint capsule might dynamically coordinate the medial meniscus (MM) by transmitting a semimembranosus action. However, their interrelationships in vivo are unclear. We aimed to determine relationships among the MM, joint capsule, and semimembranosus during passive tibial external-internal and isometric tibial internal rotation at the medial and posteromedial knees of 10 healthy individuals in vivo using ultrasound. We analyzed images of the MM and joint capsule locations at the medial and posteromedial knee and the velocity waveform similarity of each structure during rotational tasks. Both isometric internal rotation with semimembranosus action and passive tibial external rotation displaced the MM inward at the medial knee. The MM and joint capsule during these MM displacements coordinately moved with more than moderate cross-correlation coefficients (passive external and isometric internal rotations, ≥ 0.54 and ≥ 0.90, respectively). The movements of the MM and joint capsule to the semimembranosus during isometric internal rotation also coordinated with moderate cross-correlation coefficients (≥ 0.62). Therefore, the joint capsule might dynamically coordinate the MM by transmitting semimembranosus action. Whether increased tibial internal rotation or semimembranosus shortening causes MM extrusion awaits further investigation.

Analyzing muscle thickness changes in lateral abdominal muscles while exercising using virtual reality.

[Purpose] Virtual reality (VR) rehabilitation has become popular in the medical field. VR-guided exercises (VR-ge) have demonstrated positive effects on gait and trunk control. Trunk muscle activation, particularly that of the transversus abdominis (TrA), is responsible for these improvements. However, the difference in muscle activation between VR and real space remains unclear. Therefore, this study aimed to clarify the differences in trunk muscle activation during exercise therapy performed in VR and real space. [Participants and Methods] A total of 22 healthy male volunteers were divided into two equal groups: VR-ge and Control exercise (C-e) groups. Both groups performed reaching exercises in a seated position. Ultrasound imaging was used to measure the thicknesses of the right external oblique, internal oblique, and TrA muscles, both at rest and during the reaching exercises performed in six different directions. [Results] No significant differences were observed in TrA muscle thickness changes between the groups before the intervention. However, after the intervention, the VR-ge group showed significantly greater TrA muscle thickness changes during reaching compared to that of the C-e group. [Conclusion] VR-ge increased TrA activation during reaching compared to exercising in real space.

Posterior Tibial Artery Blood Flow Velocity Is Increased in Patients with Plantar Heel Pain.

Background/Objectives: This study aimed to investigate the relationship between posterior tibial artery blood flow velocity and plantar heel pain (PHP). Methods: The PHP group comprised patients diagnosed with plantar fasciitis with plantar heel pain during gait, and the control group comprised healthy participants without plantar heel pain. The peak systolic velocity of the posterior tibial artery was measured using ultrasonography; it was measured three times on each side, and the mean value was calculated. Receiver operating characteristic curve analysis was performed to calculate the peak systolic velocity cutoff value for plantar heel pain. Results: 23 patients (age 58.0 ± 16.5 years; 13 males and 10 females) and 23 healthy participants (age 51.3 ± 17.3 years; 10 males and 13 females) formed the PHP and control groups, respectively. Peak systolic velocity on the affected side was significantly greater in the PHP group (44.1 ± 13.1 cm/s) than in the control group (32.7 ± 5.9 cm/s). No significant difference was observed between the left and right sides in the PHP (7.1 ± 9.8 cm/s) and control (3.7 ± 3.0 cm/s) groups. A cutoff value of 38.2 cm/s was observed on the affected side. Conclusions: We quantified the increase in posterior tibial artery blood flow velocity in patients with plantar heel pain. Peak systolic velocity measurements can aid in quantitatively evaluating these patients. This study was registered as a clinical trial (UMIN000046875) on 1 October 2021.

Assessment of the ulnar nerve stiffness during valgus stress of the elbow using shear wave elastography: an observational cross-sectional study.

BACKGROUND: Identification of the relationship between valgus stress in the medial elbow and ulnar nerve strain during maximum external rotation of the shoulder is pivotal for the prevention and management of ulnar neuropathies. In this observational cross-sectional study, we aimed to determine the changes in ulnar nerve stiffness under valgus stress at different nerve entrapment sites. METHODS: Twenty healthy baseball players participated in the study. The stiffness of the ulnar nerve on the throwing side was assessed at two sites, the arcade of Struthers and the Osborne's ligament, at 0°, 60°, and 90° flexion by shear wave elastography using a 10-MHz linear transducer. The arcade of Struthers was defined as the proximal site and the Osborne's ligament as the distal site. Valgus stress was applied to the medial elbow at 0, 30, 50, and 70 N using a Telos stress device, and the stiffness caused by valgus stress was measured. RESULTS: At all elbow flexion angles, the stiffness of the ulnar nerve under 70 N valgus stress was higher than that under 30 N stress. The stiffness of the ulnar nerve at the proximal site was significantly higher than that at the distal site. CONCLUSION: Valgus stress increases ulnar nerve stiffness. In addition, the stiffness of the proximal site increases.

Effect of isometric quadriceps exercise on local microcirculation of the infrapatellar fat pad in female patients with knee osteoarthritis.

OBJECTIVE: To elucidate the local microcirculation of the infrapatellar fat pad (IFP) in patients with knee osteoarthritis (KOA) by determining the changes in IFP hardness and hemoglobin concentration during isometric quadriceps exercise (IQE). DESIGN: In this observational cross-sectional study, patients diagnosed with bilateral KOA were included in the KOA group (30 knees), healthy older adults in the control group (20 knees), and younger adults in the young group (20 knees). Ultrasonography was performed at rest and during IQE to measure IFP hardness based on shear wave velocity. Near-infrared spectroscopy was performed to measure oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), and total hemoglobin (cHb) in the IFP before (Baseline), during (IQE task), and after IQE (Post). IFP hardness and O2Hb, HHb, and cHb concentration were analyzed using a linear mixed model for the groups and measurement points. RESULTS: During IQE, IFP hardness changes were significantly less in the KOA group than in the other groups (KOA: 95 % confidence intervals (CIs) [-0.854, 0.028]; control: 95 % CI [-0.941, -0.341]; and young: 95 % CI [-2.305, -1.706]). In the KOA group, O2Hb concentration exhibited no significant changes at Post compared with Baseline; however, significant changes were observed in the other groups (KOA: 95 % CI [-1.176, 0.423]; control: 95 % CI [-1.452, -0.276]; and young: 95 % CI [-4.062, -2.102]). CONCLUSIONS: During IQE, changes in hardness and hemoglobin concentration in the IFP were not significant in the KOA group, suggesting impaired local microcirculation of the IFP.

Effect of Low-Intensity Pulsed Ultrasound on Macrophage Properties and Fibrosis in the Infrapatellar Fat Pad in a Carrageenan-Induced Knee Osteoarthritis Rat Model.

BACKGROUND: In the progression of knee osteoarthritis (KOA), fibrosis of the infrapatellar fat pad (IFP) is a key pathological change. Low-intensity pulsed ultrasound (LIPUS) inhibits IFP fibrosis by decreasing the gene expression and activity of hypoxia-inducible factor (HIF-1α), which is a protein involved in IFP fibrosis in KOA rat models. On the other hand, macrophages play an important role in the progression of fibrosis in various tissues, and LIPUS irradiation suppresses macrophage infiltration and inflammatory cytokine secretion. However, whether LIPUS suppresses macrophage polarity and IFP fibrosis in KOA remains unclear. Therefore, we investigated the effect of LIPUS on macrophage polarity and IFP fibrosis. MATERIALS AND METHODS: A KOA model was created by injecting carrageenin into the bilateral knee joints of Wistar rats (eight weeks old). Tissues were harvested over time for histological and molecular biological analysis. The KOA model was also subjected to LIPUS irradiation for two weeks following the injection of carrageenin. RESULTS: RM-4-positive cells were widely distributed in IFP two weeks after carrageenin administration, but M2 macrophages were significantly increased, and the Sirius red area was decreased in the LIPUS-irradiated group compared with those in the non-irradiated group. The gene expression of M1 macrophage markers was significantly decreased and that of M2 macrophage markers was significantly increased in the LIPUS-irradiated group. The expression of transforming growth factor-ß (TGF-ß) and type 1 collagen was also significantly decreased. CONCLUSION: These results suggest that LIPUS may serve as a novel approach for the treatment of KOA through its effect on M1 macrophages and suppression of TGF-ß expression.

Proposals for talonavicular joint assessment using ultrasound imaging and its reliability and validity.

[Purpose] We aimed to develop a noninvasive specific ultrasonographic assessment of the talonavicular joint during loading to facilitate the analysis of treatment of flatfoot. [Participants and Methods] Sixty healthy participants underwent ultrasound imaging of the talonavicular joint while sitting and standing. The talonavicular angle was defined as the intersection of the line connecting the navicular and talar heads and the line connecting the talar head and sustentaculum tali. Talonavicular coverage was assessed using X-ray images of 15 participants. [Results] Ultrasonographic assessment of the talonavicular joint showed a lateral shift of the navicular relative to the head of the talus from sitting to standing. The talonavicular angle was significantly larger when standing than in the sitting position. The difference in talonavicular angle values between sitting and standing significantly correlated with the differences in the talonavicular coverage values. [Conclusion] We showed that ultrasonographic talonavicular angle assessment has good reliability and moderate validity for detecting significant alignment changes in the talonavicular joints due to loading. In the future, this evaluation method should be performed before and after exercise therapy to assess and develop appropriate exercise therapy for flatfoot.

Capsular attachment on the anterosuperior femoral head-neck junction: A hypothesis about femoroacetabular impingement.

Femoroacetabular impingement (FAI), characterized by a pathological contact between the proximal femur and acetabulum, is a common precursor of hip osteoarthritis. Cam morphology is a bony prominence that causes FAI and frequently forms on the anterosuperior femoral head-neck junction. Despite anatomical consensus regarding the femoral head-neck junction as a boundary area covered by the articular cartilage and joint capsule, it remains unclear whether the joint capsule is continuous with the anterosuperior articular cartilage. For the anatomical consideration of cam morphology formation, this study aimed to investigate the histological characteristics of the capsular attachment on the anterosuperior femoral head-neck junction, particularly focusing on the presence or absence of continuity of the joint capsule to the articular cartilage. A total of 21 anterosuperior regions (seven hips each for the 12:00, 1:30, and 3:00 positions) from seven hips (three males and four females; mean age at death, 68.7 years) were histologically analyzed in this study for quantitative evaluation of the capsular thickness using histological sections stained with Masson's trichrome, as well as qualitative evaluation of the capsular attachment. The present study showed that the joint capsule, which folded proximally to the femoral head-neck junction from the recess, exhibited a blend of the fibrous and synovial regions. Notably, it not only continued with the superficial layer of the articular cartilage, but also attached to the articular cartilage via the fibrocartilage. This continuous region was relatively fibrous with dense connective tissue running in the longitudinal direction. The capsular thickness at the recess point (mean, 1.7 ± 0.9 mm) and those at the distal end of the articular cartilage (0.35 ± 0.16 mm) were significantly greater than the control value for the most superficial layer thickness of the articular cartilage (0.019 ± 0.003 mm) (Dunnett's T3, both p-value <0.001). Based on the fibrous continuity between the joint capsule and articular cartilage and its thickness, this study suggests the anatomical possibility that some mechanical stress can be transmitted from the joint capsule to the articular cartilage at the frequent sites of cam morphology.

Characteristics of ulnar neuropathy in baseball players: Focusing on the entrapment point of the ulnar nerve and valgus instability.

Background: The region where the ulnar nerve (UN) is swollen in baseball players with ulnar neuropathy is not apparent. This study investigated the UN's cross-sectional area (CSA) at each entrapment point in baseball players. We also aimed to clarify the relationship between valgus instability and the CSA of the UN. Methods: Forty baseball players were separated into healthy and ulnar neuropathy groups. The CSA and valgus instability were measured using ultrasonography (US). Relative to the medial epicondyle (MEC), the arcade of Struthers (SA) was 5 cm proximal, the cubital tunnel was the posterior part, and Osborne's ligament was defined as 3 cm distal. The ulnohumeral joint space was imaged as a low-echo space between the distal-medial corner of the trochlea and the proximal edge of the sublime tubercle. Results: The UN in the ulnar neuropathy group had significant swelling in the cubital tunnel and Osborne's ligament. We found a weak positive correlation between the CSA and ulnohumeral joint space, and the ulnohumeral joint space at rest and valgus stress. Conclusion: Evaluation and treatment of UN, especially cubital tunnel and Osborne's ligament, are necessary for the rehabilitation of baseball players presenting with ulnar neuropathy and valgus instability.

Non-invasive evaluation of autonomic responses in patients with rotator cuff tear-related nocturnal pain.

[Purpose] We aimed to determine the autonomic response in patients with rotator cuff tear-related nocturnal pain using nonlinear analysis of heart rate variability. [Participants and Methods] Twenty-eight patients with nocturnal pain who were diagnosed with a rotator cuff tear and received steroid injections, and whose nocturnal pain improved, were divided into a control group (14 patients) and a failure group (14 patients). Pulse wave was measured continuously using BACS Advance equipment (TAOS Co.) for a total of 17 min: 5 min before isometric hand grip, 2 min during isometric hand grip, 5 min after isometric hand grip, and 10 min after isometric hand grip. The autonomic nervous system activity was assessed using detrended fluctuation analysis and approximate entropy. [Results] The α1 values obtained from the detrended fluctuation analysis were significantly higher in the failure group than in the control group at each measurement period. The approximate entropy was normal in 12 (85%) patients in the control group and six (42%) patients in the failure group; it was abnormal in two (15%) patients in the control group and eight (58%) patients in the failure group. [Conclusion] Among patients experiencing nocturnal pain, several have abnormal autonomic response during isometric hand grip.

Differences and relationships between weightbearing and non-weightbearing dorsiflexion range of motion in foot and ankle injuries.

BACKGROUND: This study aimed to: (1) identify assessment methods that can detect greater ankle dorsiflexion range of motion (DROM) limitation in the injured limb; (2) determine whether differences in weightbearing measurements exist even in the absence of DROM limitations in the injured limb according to non-weightbearing measurements; and (3) examine associations between DROM in the weightbearing and non-weightbearing positions and compare those between a patient group with foot and ankle injuries and a healthy group. METHODS: Eighty-two patients with foot and ankle injuries (e.g., fractures, ligament and tendon injuries) and 49 healthy individuals participated in this study. Non-weightbearing DROM was measured under two different conditions: prone position with knee extended and prone position with knee flexed. Weightbearing DROM was measured as the tibia inclination angle (weightbearing angle) and distance between the big toe and wall (weightbearing distance) at maximum dorsiflexion. The effects of side (injured, uninjured) and measurement method on DROM in the patient groups were assessed using two-way repeated-measures ANOVA and t-tests. Pearson correlations between measurements were assessed. In addition, we analyzed whether patients without non-weightbearing DROM limitation (≤ 3 degrees) showed limitations in weightbearing DROM using t-tests with Bonferroni correction. RESULTS: DROM in patient groups differed significantly between legs with all measurement methods (all: P < 0.001), with the largest effect size for weightbearing angle (d = 0.95). Patients without non-weightbearing DROM limitation (n = 37) displayed significantly smaller weightbearing angle and weightbearing distance on the injured side than on the uninjured side (P < 0.001 each), with large effect sizes (d = 0.97-1.06). Correlation coefficients between DROM in non-weightbearing and weightbearing positions were very weak (R = 0.17, P = 0.123) to moderate (R = 0.26-0.49, P < 0.05) for the patient group, and moderate to strong for the healthy group (R = 0.51-0.69, P < 0.05). CONCLUSIONS: DROM limitations due to foot and ankle injuries may be overlooked if measurements are only taken in the non-weightbearing position and should also be measured in the weightbearing position. Furthermore, DROM measurements in non-weightbearing and weightbearing positions may assess different characteristics, particularly in patient group. LEVEL OF EVIDENCE: Level IV, cross-sectional study.

In vivo interrelationships between the gluteus minimus and hip joint capsule in the hip internal rotation position with flexion.

BACKGROUND: The flexion adduction internal rotation (FADIR) test is performed by the combined motions of hip flexion (with knee flexion), adduction, and internal rotation, and can often reproduce anterior hip pain consistent with an individual's presenting pain. Since it has high sensitivity for intraarticular pathology diagnosis but low specificity, understanding the extraarticular pathology that can induce anterior hip pain in the FADIR test may also be essential. This study hypothesized that the interrelationships between the joint capsule and gluteus minimus differ in individuals with and without FADIR-positive pain and aimed to elucidate the in vivo interrelationships at hip internal rotation in 90°-flexion, which is also often restricted in individuals with FADIR-positive pain. METHODS: Ten hips were included in the FADIR-positive group, and ten hips without hip pain in the FADIR test were included in a control group. Based on the ultrasound images at the four hip rotation conditions (20° and 10° external rotations, 0° external/internal rotation, and 10° internal rotation), orientation measurements of the gluteus minimus (muscle belly portion) and joint capsule were performed and quantitatively compared between the FADIR-positive and control groups. Additionally, 3 hips of 3 participants were randomly selected from each of the control and FADIR-positive groups for magnetic resonance imaging analysis. RESULTS: At 0°-external/internal and 10°-internal rotation, on ultrasound images, fibers of the gluteus minimus and joint capsule in the FADIR-positive group were significantly more oriented in the same direction than those in the control group. Magnetic resonance imaging showed that the loose connective tissue between the gluteus minimus and joint capsule was prominent at 10°-internal rotation in the control group, although this was not apparent in the FADIR-positive group. CONCLUSIONS: At hip internal rotation in 90° flexion, the muscular belly portion of the gluteus minimus and joint capsule were oriented in the same direction to a greater extent in the FADIR-positive group than in the control group owing to a morphological change in the loose connective tissue between them. The pathological changes in the loose connective tissue may inhibit smooth movement of the gluteus minimus relative to the joint capsule in individuals with FADIR-positive pain.

Effects of short foot exercises with ultrasound bio-feedback on motor learning and foot alignment: A double blinded randomized control trial.

BACKGROUND: Short foot exercises (SFE) take a long time to master and require a feedback tool to improve motor learning. OBJECTIVE: This study aimed to investigate the effect of bio-feedback of talonavicular joint movements in learning SFE with ultrasound (US) imaging. METHODS: This study included thirty-one healthy volunteers and was designed as a double-blind randomized control trial. Subjects were randomly assigned to one of two groups: the control group, which performed SFE under verbal instruction, and the US bio-feedback (USBF) group, which performed SFE with real-time bio-feedback of the talonavicular joint alignment. All subjects underwent two sessions of 5 minutes each, and SFE was performed as a self-exercise, between sessions, for one week. The difference in foot length and navicular height were assessed at baseline, after Session 1, before Session 2, and one week after Session 2. These differences were compared between the two groups using the Mann-Whitney U test. RESULTS: In terms of navicular height change, the USBF group (7.5 ± 4.3 mm) was significantly higher than the control group (4.2 ± 3.3 mm) one week after session 2 (p= 0.04, effect size = 0.86). CONCLUSION: SFE with USBF is an effective intervention for performing SFE.

Effects of Compression Intervention on the Thigh Using Elastic Bandage on Lateral Femoral Pain After Trochanteric Fractures: A Multicenter Randomized Controlled Trial.

A trochanteric fracture is one type of hip fracture. Management of postoperative pain after trochanteric fracture that is caused by decreased gliding between tissues in the lateral thigh is not established. The aim of this study was to examine the effect of compression of the thigh using an elastic bandage on trochanteric fracture after surgery. Multicenter randomized controlled trial was conducted in collaboration with the Comprehensive Rehabilitation Unit (sub-acute rehabilitation Unit) in two hospitals. Eligible volunteers (n = 34) with trochanteric fractures after surgery were randomly assigned to two groups. In the treatment group, participants practiced standing and walking under compression of the thigh with an elastic bandage. The control group was blinded to the intervention and practiced standing and walking under non-compression of the thigh with an elastic bandage. Both groups underwent a standard physical therapy program 2 times a day, daily. Two-way repeated measures of ANOVA showed significant main effect between the groups for gliding between tissue (p < .001), lateral femoral pain (p < .001), subcutaneous tissue thickness (p = .044). Compression of the thigh with an elastic bandage significantly improved subcutaneous tissue thickness, gliding between tissues, lateral thigh pain. Gait velocity improved with these functional improvements.

The effects of the functional garment on the biomechanics during the single leg drop landing.

INTRODUCTION: A functional biomechanics garment (FBG) may help to prevent injury by improved kinematics during motion such as single leg drop landing (SLDL). The purpose of this study was to investigate the effects of the FBG on the biomechanics of SLDL. METHOD: Seventeen female university basketball players participated. Characteristics of the FBG were designed based on biomechanics during weight-loaded performance of human movement. The average values of lower limb kinematics and kinetics in the sagittal and frontal planes from 3 SLDL with and without FBG were measured and compared. RESULTS: The maximum varus angle of the knee showed a significant difference between the use of FBG (15.3 ± 15.1°) and without the use of FBG (5.9 ± 15.4°), the flexion angular displacement of the hip (with FBG, 21.5 ± 8.1°; without FBG, 24.0 ± 6.7°) between with and without FBG. The moment of the hip with FGB (1.1 ± 0.6 Nm) was significantly smaller than without FGB (1.4 ± 0.8 Nm). DISCUSSION: Regarding function of the FBG, the rigid part of the hip could counter the excessive adduction and flexion of the hip, and the elastic part of the thigh could support the varus moment when the elastic part stretched. Therefore, the subjects with FBG could control the frontal motion of the knee, which has a risk of knee injury, such as the dynamic valgus of the knee during the SLDL. CONCLUSION: Use of the FBG decreases dynamic knee valgus, which reduces risk of knee injury.

Ultrasound Imaging of Subtalar Joint Instability for Chronic Ankle Instability.

The purpose of this study was to develop the assessment of subtalar joint instability with chronic ankle instability (CAI) using ultrasonography. Forty-six patients with anterior talofibular ligament (ATFL) abnormalities and a history of ankle sprain were divided into CAI (21.2 ± 5.9 y/o, 7 males and 17 females) and asymptomatic groups (21.0 ± 7.4 y/o, 9 males and 12 females) on the basis of subjective ankle instability assessed using the CAIT and the Ankle Instability Instrument Tool (AIIT). Twenty-six age-matched feet participated in a control group (18.9 ± 7.0 y/o, 9 males and 17 females). Ultrasound measurements of the width of the posterior subtalar joint facet were obtained at rest and maximum ankle inversion (subtalar joint excursion; STJE). The differences in STJE among the three groups were assessed by one-way ANOVA. The relationship between STJE and subjective ankle instability was assessed using Spearman's correlation tests. The STJE value was significantly greater in the CAI group (2.3 ± 0.8 mm) than in the asymptomatic (1.0 ±0.4 mm) and control groups (0.8 ±0.2 mm) (p < 0.001, effect size: 0.64). STJE had significant negative correlations with CAIT (r = -0.71, p < 0.01), and significant positive correlations with AIIT (r = 0.74, p < 0.01). The cut-off value to distinguish between the CAI and asymptomatic groups was 1.7 mm using the ROC curve.

Automatic Identification of Ultrasound Images of the Tibial Nerve in Different Ankle Positions Using Deep Learning.

Peripheral nerve tension is known to be related to the pathophysiology of neuropathy; however, assessing this tension is difficult in a clinical setting. In this study, we aimed to develop a deep learning algorithm for the automatic assessment of tibial nerve tension using B-mode ultrasound imaging. To develop the algorithm, we used 204 ultrasound images of the tibial nerve in three positions: the maximum dorsiflexion position and -10° and -20° plantar flexion from maximum dorsiflexion. The images were taken of 68 healthy volunteers who did not have any abnormalities in the lower limbs at the time of testing. The tibial nerve was manually segmented in all images, and 163 cases were automatically extracted as the training dataset using U-Net. Additionally, convolutional neural network (CNN)-based classification was performed to determine each ankle position. The automatic classification was validated using five-fold cross-validation from the testing data composed of 41 data points. The highest mean accuracy (0.92) was achieved using manual segmentation. The mean accuracy of the full auto-classification of the tibial nerve at each ankle position was more than 0.77 using five-fold cross-validation. Thus, the tension of the tibial nerve can be accurately assessed with different dorsiflexion angles using an ultrasound imaging analysis with U-Net and a CNN.

Posteromedial capsular anatomy of the tibia for consideration of the medial meniscal support structure using a multidimensional analysis.

Medial meniscal extrusion (MME) is a structural abnormality that leads to early knee osteoarthritis; however, its formation remains debated. For anatomical consideration of the mechanism underlying MME formation, we examined the capsular attachment on the posteromedial tibia and its layered association with the semimembranosus. Fourteen knees of eight body donors were analyzed in this study; six knees were grouped for macroscopic analysis, whereas four knees each were grouped for histological and phosphotungstic acid-enhanced micro-computed tomography analyses. The capsular attachment varied in width according to location and was not distant from the articular cartilage and posterior root. A portion of the posteromedial joint capsule formed the semimembranosus tendinous sheath. The dense fibrous membrane superficial to the semimembranosus, which was continuous from its tendinous sheath, existed as one of the layers of the joint capsule. The aforementioned findings were confirmed in all specimens. Based on the capsular attachment and its layered association with the semimembranosus, the conventional posteromedial knee ligaments may be only a part of the joint capsule divided into two layers by the semimembranosus. If the coordinated action of the joint capsule and semimembranosus partially contributes to the medial meniscus stability, such a structural problem may affect MME formation.

Diaphragm dome height on chest radiography as a predictor of dynamic lung hyperinflation in COPD.

Background and objective: Dynamic lung hyperinflation (DLH) can play a central role in exertional dyspnoea in patients with COPD. Chest radiography is the basic tool for assessing static lung hyperinflation in COPD. However, the predictive capacity of DLH using chest radiography remains unknown. This study was conducted to determine whether DLH can be predicted by measuring the height of the right diaphragm (dome height) on chest radiography. Methods: This single-centre, retrospective cohort study included patients with stable COPD with pulmonary function test, cardiopulmonary exercise test, constant load test and pulmonary images. They were divided into two groups according to the median of changes of inspiratory capacity (ΔIC=IC lowest - IC at rest). The right diaphragm dome height and lung height were measured on plain chest radiography. Results: Of the 48 patients included, 24 were classified as having higher DLH (ΔIC ≤-0.59 L from rest; -0.59 L, median of all) and 24 as having lower DLH. Dome height correlated with ΔIC (r=0.66, p<0.001). Multivariate analysis revealed that dome height was associated with higher DLH independent of % low attenuation area on chest computed tomography and forced expiratory volume in 1 s (FEV1) % predicted. Furthermore, the area under the receiver operating characteristic curve of dome height to predict higher DLH was 0.86, with sensitivity and specificity of 83% and 75%, respectively, at a cut-off of 20.5 mm. Lung height was unrelated to ΔIC. Conclusion: Diaphragm dome height on chest radiography may adequately predict higher DLH in patients with COPD.

Tibial nerve dynamics during ankle dorsiflexion: The relationship between stiffness and excursion of the tibial nerve.

Peripheral nerves extend with a gradual increase in stiffness and also with excursion, namely reduction of fiber bundle waviness, to adapt to joint movements. Although the close relationships between the tibial nerve (TN) excursion and stiffness during ankle dorsiflexion in cadaver studies, the precise in vivo their relationships remain unclear. We hypothesized that the excursion of the TN can be estimated from its stiffness in vivo using shear-wave elastography. This study aimed to analyze the relationships between the TN stiffness at the plantarflexion and dorsiflexion and TN excursion during dorsiflexion using ultrasonography. Twenty-one healthy adults participated in constant-velocity movements of the ankle joint with a 20° range from the maximum dorsiflexion, and the TN was imaged using an ultrasound imaging system. The maximum flow velocity value and the TN excursion distance per dorsiflexion were then calculated as indexes of excursion using the application software Flow PIV. The shear wave velocities of the TN at plantarflexion and dorsiflexion were also measured. Based on our single linear regression, the shear wave velocities of the TN at the plantarflexion had the strongest effect on the excursion indexes, followed by the those at dorsiflexion. Ultrasonographic shear wave velocity could predict the TN excursion if measured under mild plantarflexion of the ankle joint, and might have a close biomechanical relation to the total waviness of the TN.