Which is superior in improving the performance of short-distance sprints starting in a lateral direction, forward- or false-step technique?

When athletes in ball game sports start sprinting in the forward direction from a parallel stance, they commonly use the forward- and false-step techniques. Previous studies focusing on the performance of short-distance sprints starting in the forward direction have demonstrated that the false-step technique is superior to the forward-step technique. Although athletes start sprinting in various directions based on relevant visual cues, such as movements of the ball or the opponent players, the effectiveness of each technique for starting a sprint in the other direction is still unclear. This study aims to clarify the effectiveness of each technique in improving the performance of the short-distance sprint starting in the lateral direction. In this study, 20 athletes started 5-m sprints in the right direction from the parallel stance using either of these two techniques. Kinematic and kinetic analyses were performed from movement initiation to the flight phase after the second step in the sprinting direction. The average and terminal sprint velocities throughout this range were larger in the forward-step technique (p = 0.039 and 0.003), indicating its superiority in traveling and accelerating performance. The change of sprint velocity in the initial phase until the contact of the first step in the sprinting direction was smaller in the false-step technique (p < 0.001), although this phase included "false step." These results indicate that the forward-step technique is superior in sprints starting in the lateral direction, and the advantage results from greater acceleration in the initial phase immediately after movement initiation. These findings imply the sprint-directional dependence of the relative superiority of these techniques, providing an impetus for athletes and coaches to consider and establish the effective training and coaching methods of short-distance sprints.

Residual Paresthesia After Surgery for Degenerative Cervical Myelopathy: Incidence and Impact on Clinical Outcomes and Satisfaction.

STUDY DESIGN: Multicenter, prospective cohort study. OBJECTIVE: The current study aimed to identify the incidence of residual paresthesias after surgery for degenerative cervical myelopathy (DCM), and to demonstrate the impact of these symptoms on clinical outcomes and patient satisfaction. SUMMARY OF BACKGROUND DATA: Surgery for DCM aims to improve and/or prevent further deterioration of physical function and quality-of-life (QOL) in the setting of DCM. However, patients are often not satisfied with their treatment for myelopathy when they have severe residual paresthesias, even when physical function and QOL are improved after surgery. MATERIALS AND METHODS: The authors included 187 patients who underwent laminoplasty for DCM. All patients were divided into two groups based on their visual analog scale score for paresthesia of the upper extremities at one year postoperatively (>40 vs. ≤40 mm). Preoperative factors, changes in clinical scores and radiographic factors, and satisfaction scales at one year postoperatively were compared between groups. The authors used mixed-effect linear and logistic regression modeling to adjust for confounders. RESULTS: Overall, 86 of 187 patients had severe residual paresthesia at one year postoperatively. Preoperative patient-oriented pain scale scores were significantly associated with postoperative residual paresthesia ( P =0.032). A mixed-effect model demonstrated that patients with severe postoperative residual paresthesia showed significantly smaller improvements in QOL ( P =0.046) and myelopathy ( P =0.037) than patients with no/mild residual paresthesia. Logistic regression analysis identified that residual paresthesia was significantly associated with lower treatment satisfaction, independent of improvements in myelopathy and QOL (adjusted odds ratio: 2.5, P =0.010). CONCLUSION: In total, 45% of patients with DCM demonstrated severe residual paresthesia at one year postoperatively. These patients showed significantly worse treatment satisfaction, even after accounting for improvements in myelopathy and QOL. As such, in patients who experience higher preoperative pain, multidisciplinary approaches for residual paresthesia, including medications for neuropathic pain, might lead to greater clinical satisfaction. LEVEL OF EVIDENCE: 3.

The Impact of Multidisciplinary Approaches to Social Functioning on Surgical Outcomes After Surgery for Cervical Myelopathy.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To identify the effects of multidisciplinary approaches (MAs) to improve social functioning (SF) on 1-year surgical outcomes in patients with cervical myelopathy. SUMMARY OF BACKGROUND DATA: Despite significant improvement in cervical myelopathy, a patient's quality of life (QOL) sometimes does not improve postoperatively. A previous study revealed that SF, rather than myelopathy severity, correlated with QOL improvement after decompression surgery for cervical myelopathy. PATIENTS AND METHODS: This study compared two prospective cohorts in Japan. Patients who underwent cervical laminoplasty for cervical myelopathy from 2018 to 2020 were enrolled in the control cohort. Patients who underwent the same surgery with the same indications between 2020 and 2021 were enrolled in the MA cohort. Patients in the control cohort were treated with a standard care protocol, and those in the MA cohort were treated with a multidisciplinary protocol that focused on SF improvement. The changes in the total Japanese Orthopedic Association (JOA) score and in the domains of the JOA scores (upper limb function, lower limb function, upper limb sensory, and lower limb sensory) from preoperatively to 1 year postoperatively were compared between the control and MA cohorts using a mixed-effect model. RESULTS: The control and MA cohorts comprised 140 and 31 patients, respectively. The improvement in the JOA score was significantly better in the MA cohort than in the control cohort ( P = 0.040). In analyses of each JOA score domain, the improvement of upper limb function was significantly better in the MA cohort than in the control cohort ( P = 0.033). Similarly, the MA cohort demonstrated significantly higher patient-reported outcomes for upper extremity function than the control cohort ( P < 0.001). In addition, the self-care domain of QOL score at 1 year postoperatively was significantly higher in the MA cohort than in the control cohort ( P = 0.047). CONCLUSION: MAs to improve/rebuild a patient's SF were effective in improving cervical myelopathy and the self-care domain of QOL. This study is the first to demonstrate the effectiveness of postoperative MAs in patients with cervical myelopathy. LEVEL OF EVIDENCE: Level 3.

Behavior and measurement method of inter-core crosstalk in multicore fibers with core-dependent loss.

We quantitatively discussed the effect of core-dependent loss (CDL) on the crosstalk (XT) of multicore fibers (MCFs). In practical ranges of XT and CDL, CDL has no significant effect on power coupling coefficients and XT between cores. Therefore, taking into account the CDL-induced signal attenuation difference among cores is sufficient when considering the signal-to-XT ratio in an MCF with CDL. We also analytically investigated the effect of CDL on XT measurements, and found that the effects of the CDLs induced in an MCF as a measurement target and a measurement setup (including input/output devices) can be canceled in the geometric mean of linear values (or the arithmetic mean of decibel values) of the XT by switching the source core and destination core of the XT.

Development of locomotive syndrome in elderly population after COVID-19 outbreak: A population-based cross-sectional study with over 12,000 participants.

BACKGROUND: Restrictions during the coronavirus disease 2019 (COVID-19) pandemic have decreased physical activity levels, which may result in locomotive syndrome. This study evaluated the change in locomotive syndrome prevalence and associated risk factors among an elderly population before and after a coronavirus outbreak. METHODS: This written self-administered cross-sectional survey was conducted in conjunction with the coronavirus disease vaccination program in Habikino City, Japan. Participants who were aged ≥65 years completed the five-question Geriatric Locomotive Function Scale before and during the pandemic. The diagnosis of locomotive syndrome and its stage was based on the Geriatric Locomotive Function Scale score: stage 1 (2-3 points), 2 (4-5 points), and 3 (≥6 points). Data on lifestyle changes, including regular exercise, during the pandemic were collected. RESULTS: This study included 12,197 participants (36.7% of the city's total elderly residents). The prevalence of locomotive syndrome increased from 41.3% to 47.1% after the outbreak. In total, 765 (6.3% of overall population) and 295 (9.5% of the participants who had stages 1-2 before the pandemic) participants developed locomotive syndrome and stage 3 locomotive syndrome, respectively. The multivariate logistic regression analysis indicated that a decrease in exercise was significantly associated with the onset of locomotive syndrome (all stages) (odds ratio = 2.5, p < 0.001) and locomotive syndrome stage 3 (odds ratio = 2.6, p < 0.001). CONCLUSIONS: Extrapolation of the study's findings to the entire population of Japan suggests that approximately 2 million elderly individuals might develop locomotive syndrome after the coronavirus outbreak. Additionally, 10% of the participants with mild-moderate locomotive syndrome before the pandemic may develop severe locomotive syndrome after the outbreak. The greatest risk factor for new-onset or worsening locomotive syndrome was a decrease in daily exercise. Thus, there is an urgent need for adequate exercise guidelines during the coronavirus pandemic, especially for the elderly population.

Postoperative Physical Therapy Program Focused on Low Back Pain Can Improve Treatment Satisfaction after Minimally Invasive Lumbar Decompression.

Patient satisfaction is crucial in pay-for-performance initiatives. To achieve further improvement in satisfaction, modifiable factors should be identified according to the surgery type. Using a prospective cohort, we compared the overall treatment satisfaction after microendoscopic lumbar decompression between patients treated postoperatively with a conventional physical therapy (PT) program (control; n = 100) and those treated with a PT program focused on low back pain (LBP) improvement (test; n = 100). Both programs included 40 min outpatient sessions, once per week for 3 months postoperatively. Adequate compliance was achieved in 92 and 84 patients in the control and test cohorts, respectively. There were no significant differences in background factors; however, the patient-reported pain score at 3 months postoperatively was significantly better, and treatment satisfaction was significantly higher in the test than in the control cohort (-0.02 ± 0.02 vs. -0.03 ± 0.03, p = 0.029; 70.2% vs. 55.4%, p = 0.045, respectively). In the multivariate logistic regression analysis, patients treated with the LBP program tended to be more satisfied than those treated with the conventional program, independent of age, sex, and diagnosis (adjusted odds ratio = 2.34, p = 0.012). Postoperative management with the LBP program could reduce pain more effectively and aid spine surgeons in achieving higher overall satisfaction after minimally invasive lumbar decompression, without additional pharmacological therapy.

Critical Current Density and Vortex Dynamics in Pristine and Irradiated KCa2Fe4As4F2.

We report the critical current density (Jc) and vortex pinning properties in single crystals of a novel iron-based superconductor (IBS) KCa2Fe4As4F2 with large Jc in the pristine state, before and after introduction of artificial defects by swift-particle irradiation. The effects of 2.6 GeV U and 3 MeV proton irradiations in KCa2Fe4As4F2 single crystals on transition temperature Tc and Jc, including its dose dependence, are systematically studied. Jc~8 MA/cm2 under a self-field at 2 K in the pristine crystal is strongly enhanced up to 19.4 and 17.5 MA/cm2 by irradiation of 2.6 GeV U-ions and 3 MeV protons, respectively. Suppression of Tc and dose dependence of Jc in KCa2Fe4As4F2 is different from that in a representative IBS of (Ba,K)Fe2As2, which can be explained by considering the presence of embedded defects in pristine KCa2Fe4As4F2. The vortex dynamics in the pristine and proton irradiated KCa2Fe4As4F2 single crystals are also investigated from the analyses of the field dependence of Jc and the normalized magnetic relaxation rate. In addition to the contribution of embedded defects, weak collective pinning is considered for comprehensive analyses. Vortex dynamics in KCa2Fe4As4F2 is similar to those in (Ba,K)Fe2As2 to some extent, and different from that in anisotropic Li0.8Fe0.2OHFeSe. Large anisotropy, due to the presence of insulating blocking layers in KCa2Fe4As4F2, which leads to much lower irreversibility field (Hirr) compared with 122-type IBSs, strongly affect the vortex dynamics.

Clinical Outcomes of Minimally Invasive Posterior Decompression for Lumbar Spinal Stenosis with Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare the clinical outcomes 5 years after minimally invasive posterior decompression for lumber spinal stenosis (LSS) between patients with and without degenerative spondylolisthesis (DS). SUMMARY OF BACKGROUND DATA: Indications for surgical procedures for patients with LSS and DS are still under investigation. Since minimally invasive surgery does not affect most anatomical structures, preoperative DS may not negatively affect the clinical outcomes of minimally invasive posterior decompression. METHODS: Overall, 198 patients with LSS who underwent microendoscopic or microscopic decompression and were followed up for more than 5 years postoperatively were included in the present study. Patients who showed a segmental kyphosis >5° at the surgical level during flexion were treated with fusion surgery. However, other patients, including those with DS, were treated with posterior decompression. The patients were divided into two groups: the DS group included 82 patients with >3-mm slip and the non-DS group included 112 patients with ≤3-mm slip or without slip. A mixed-effects model adjusted for age and sex was used to compare the improvements in the visual analog scale score for low-back pain and the Japanese Orthopaedic Association score of the two groups. For subgroup analysis (n = 53), the changes in the preoperative physical component summary and the mental component summary of Short Form-36 of the two groups at 5 years after surgery were evaluated. RESULTS: There was no significant difference in the improvement of preoperative low-back pain visual analog scale score and Japanese Orthopaedic Association score 5 years after surgery between the two groups. Subgroup analysis showed no significant difference between the two groups in the improvement of preoperative physical component summary and mental component summary 5 years after surgery. CONCLUSION: After carefully eliminating patients with segmental instability, DS did not affect the clinical outcomes of minimally invasive decompression surgery.Level of Evidence: 3.

Quantitative evaluation of subjective posture recognition by physiotherapists using a 3D motion capture.

[Purpose] This study evaluated subjective posture recognition by physiotherapists with expertise in posture, examined the quantification of posture using a three-dimensional (3D) motion capture, and described posture-based characteristics. [Participants and Methods] We photographed good, normal, and bad postures in 12 participants using an infrared camera, and the resultant data were analyzed. [Results] We observed the largest displacement from a good to a bad posture in the tenth thoracic vertebra on the X-axis in the anterior-posterior direction in comparison with other index points. Further, we observed considerable differences between good and bad postures compared with other index points. Moreover, we noted significant differences between the amount of displacement between good to a normal posture and from a good to a bad posture. The vertical displacement of the Z-axis was smaller than other index points. [Conclusion] Th10 captured features from the three postures. The X-axis was displaced most between good and bad postures. Further, the amount of displacement on the Z-axis was less between good and bad posture, rendering it difficult to capture features. Therefore, the findings reported herein can be used to compare the front and rear directions of the X-axis for capturing postural changes.

Bioluminescence burst caused by a process in carbohydrate metabolism in a luciferase reporter strain of Escherichia coli.

We previously reported that Escherichia coli strains carrying a firefly luciferase reporter gene (luc+) showed a posttranslationally-generated bioluminescence burst upon entry into the stationary phase. In this paper, we studied the mechanism underpinning this burst by using a series of "Keio" gene deletion strains. When luc+ driven by the lac gene promoter (lacp::luc+) was introduced into a group of Keio strains, the resulting reporter strains showed significantly altered timing and/or sizes of the burst. Remarkably, a reporter strain that lacked phosphoglucose isomerase (PGI), which catalyzes the second step of glycolysis, showed no burst, while the onset of the stationary phase of this strain was the same as that of the wild-type (WT) reporter strain. Consistently, the WT reporter strain showed no burst, when grown on arabinose or xylose instead of glucose as the carbon source. These results suggest that a process in carbohydrate metabolism is involved in the mechanism of generation of the burst. We measured temporal changes in intracellular NADPH concentrations but could not detect a significant increase or decrease relative to the occurrence of the burst. Functional implications and possible applications of the burst are discussed.

From Focal Stack to Tensor Light-Field Display.

We propose a method of using a focal stack, i.e., a set of differently focused images, as the input for a novel light field display called a "tensor display." Although this display consists of only a few light attenuating layers located in front of a backlight, it can be viewed from many directions (angles) simultaneously without the resolution of each viewing direction being sacrificed. Conventionally, a transmittance pattern is calculated for each layer from a light field, namely, a set of dense multi-view images (typically dozens) that are to be observed from different directions. However, preparing such a massive amount of images is often cumbersome for real objects. We developed a method that does not require a complete light field as the input; instead, a focal stack composed of only a few differently focused images is directly transformed into layer patterns. Our method greatly reduces the cost of acquiring data while also maintaining the quality of the output light field. We validated the method with experiments using synthetic light field datasets and a focal stack acquired by an ordinary camera.

Quantification of hand synovitis in rheumatoid arthritis: Arterial mask subtraction reinforced with mutual information can improve accuracy of pixel-by-pixel time-intensity curve shape analysis in dynamic MRI.

BACKGROUND: Synovitis, which is a hallmark of rheumatoid arthritis (RA), needs to be precisely quantified to determine the treatment plan. Time-intensity curve (TIC) shape analysis is an objective assessment method for characterizing the pixels as artery, inflamed synovium, or other tissues using dynamic contrast-enhanced MRI (DCE-MRI). PURPOSE/HYPOTHESIS: To assess the feasibility of our original arterial mask subtraction method (AMSM) with mutual information (MI) for quantification of synovitis in RA. STUDY TYPE: Prospective study. SUBJECTS: Ten RA patients (nine women and one man; mean age, 56.8 years; range, 38-67 years). FIELD STRENGTH/SEQUENCE: 3T/DCE-MRI. ASSESSMENT: After optimization of TIC shape analysis to the hand region, a combination of TIC shape analysis and AMSM was applied to synovial quantification. The MI between pre- and postcontrast images was utilized to determine the arterial mask phase objectively, which was compared with human subjective selection. The volume of objectively measured synovitis by software was compared with that of manual outlining by an experienced radiologist. Simple TIC shape analysis and TIC shape analysis combined with AMSM were compared in slices without synovitis according to subjective evaluation. STATISTICAL TESTS: Pearson's correlation coefficient, paired t-test and intraclass correlation coefficient (ICC). RESULTS: TIC shape analysis was successfully optimized in the hand region with a correlation coefficient of 0.725 (P < 0.01) with the results of manual assessment regarded as ground truth. Objective selection utilizing MI had substantial agreement (ICC = 0.734) with subjective selection. Correlation of synovial volumetry in combination with TIC shape analysis and AMSM with manual assessment was excellent (r = 0.922, P < 0.01). In addition, negative predictive ability in slices without synovitis pixels was significantly increased (P < 0.01). DATA CONCLUSIONS: The combination of TIC shape analysis and image subtraction reinforced with MI can accurately quantify synovitis of RA in the hand by eliminating arterial pixels. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Accurate quantitative assessment of synovitis in rheumatoid arthritis using pixel-by-pixel, time-intensity curve shape analysis.

OBJECTIVE: To improve on the reproducibility and sensitivity of the assessment of patients with rheumatoid arthritis (RA), two semi-automated measurement methods of the area of enhancing pannus (AEP), based on thresholding (AEP_THRES) and pixel-by-pixel time-intensity curve analysis (AEP_TIC), were evaluated as an alternative for the gold-standard manual contouring method (AEP_MANUAL). METHODS: 8 patients (7 females and 1 male) with RA of the wrist or finger joints participated in the study. A three-dimensional contrast-enhanced dynamic sequence was used at 3 T. After identifying the most relevant time-intensity curve (TIC) shape in terms of synovitis by comparing with the synovitis score using the RA-MRI scoring system, three different approaches for measuring the AEP were performed. Spearman's test of rank correlation was used to compare AEPs via two semi-automated methods (AEP_THRES and AEP_TIC) against manual segmentation (AEP_MANUAL) in the entire hand region as well as the wrist and the finger regions. RESULTS: The TIC shape of "washout after fast initial enhancement" had excellent correlation with synovitis score (r = 0.809). The correlation coefficient between AEP_TIC and AEP_MANUAL was evaluated to be better than that of AEP_THRES and AEP_MANUAL in the wrist region (AEP_THRES: r = 0.716, AEP_TIC: r = 0.815), whereas these were of comparable accuracy for the entire hand and the finger regions. CONCLUSION: This study suggests that TIC analysis may be an alternative to manual contouring for pannus quantification and provides important clinical information of the extent of the disease in patients with RA. ADVANCES IN KNOWLEDGE: TIC shape analysis can be applied for new quantitative assessment for RA synovitis in the wrist.