Reliability and validity of pose estimation algorithm for measurement of knee range of motion after total knee arthroplasty.

We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measurement of knee range of motion after total knee arthroplasty (TKA), in comparison to radiography and goniometry. In this prospective observational study, we analyzed 35 primary TKAs (24 patients) for knee osteoarthritis. We measured the knee angles in flexion and extension using OpenPose, radiography, and goniometry. We assessed the test-retest reliability of each method using intraclass correlation coefficient (1,1). We evaluated the ability to estimate other measurement values from the OpenPose value using linear regression analysis. We used intraclass correlation coefficients (2,1) and Bland-Altman analyses to evaluate the agreement and error between radiography and the other measurements. OpenPose had excellent test-retest reliability (intraclass correlation coefficient (1,1) = 1.000). The R2 of all regression models indicated large correlations (0.747 to 0.927). In the flexion position, the intraclass correlation coefficients (2,1) of OpenPose indicated excellent agreement (0.953) with radiography. In the extension position, the intraclass correlation coefficients (2,1) indicated good agreement of OpenPose and radiography (0.815) and moderate agreement of goniometry with radiography (0.593). OpenPose had no systematic error in the flexion position, and a 2.3° fixed error in the extension position, compared to radiography. OpenPose is a reliable and valid tool for measuring flexion and extension positions after TKA. It has better accuracy than goniometry, especially in the extension position. Accurate measurement values can be obtained with low error, high reproducibility, and no contact, independent of the examiner's skills.

Reliability and validity of OpenPose for measuring hip-knee-ankle angle in patients with knee osteoarthritis.

We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measuring hip-knee-ankle (HKA) angle in patients with knee osteoarthritis, by comparing it with radiography. In this prospective study, we analysed 60 knees (30 patients) with knee osteoarthritis. We measured HKA angle using OpenPose and radiography before or after total knee arthroplasty and assessed the test-retest reliability of each method with intraclass correlation coefficient (1, 1). We evaluated the ability to estimate the radiographic measurement values from the OpenPose values using linear regression analysis and used intraclass correlation coefficients (2, 1) and Bland-Altman analyses to evaluate the agreement and error between OpenPose and radiographic measurements. OpenPose had excellent test-retest reliability (intraclass correlation coefficient (1, 1) = 1.000) and excellent agreement with radiography (intraclass correlation coefficient (2, 1) = 0.915), with regression analysis indicating a large correlation (R2 = 0.865). OpenPose also had a 1.1° fixed error and no systematic error when compared with radiography. This is the first study to validate the use of OpenPose for the estimation of HKA angle in patients with knee osteoarthritis. OpenPose is a reliable and valid tool for measuring HKA angle in patients with knee osteoarthritis. OpenPose, which enables non-invasive and simple measurements, may be a useful tool to assess changes in HKA angle and monitor the progression and post-operative course of knee osteoarthritis. Furthermore, this validated tool can be used not only in clinics and hospitals, but also at home and in training gyms; thus, its use could potentially be expanded to include self-assessment/monitoring.

Prevalence of low back pain and its associated risk factors among professions and workers in health, medical, and welfare facilities in Japan.

BACKGROUND: The prevalence of low back pain (LBP) and its associated risk factors, including physical function, are not fully clarified among health, medical, and welfare facility professionals and workers. Furthermore, issues related to the prevention of LBP are not completely understood. OBJECTIVE: To investigate the prevalence of LBP and associated risk factors, including physical function, in professionals and workers in health, medical, and welfare facilities. DESIGN: Cross-sectional study. SETTING: Physical examinations for LBP were conducted, and data were collected at health, medical, and welfare facilities in Japan. PARTICIPANTS: A total of 1085 health, medical, and welfare facility professionals and workers participated in the study. MAIN OUTCOME MEASURES: Prevalence was calculated based on the presence or absence of symptoms of LBP at the time of survey. Then, bivariate analysis was conducted to examine the relationship between LBP and age, gender, occupation, history of treatment for LBP, passive straight leg raising (SLR) angle, and abdominal muscle strength. Furthermore, multivariate analysis was performed to examine the relationship between LBP and the six risk factors. RESULTS: The prevalence of LBP was high (74.8%). Bivariate analysis showed a significantly higher percentage of nursing professionals (46.2%) in the LBP group (p < .001). The association between LBP and the risk factors in multivariate analysis was as follows: history of treatment for LBP (odds ratio [OR] = 3.92, 95% confidence interval [CI] 2.63-5.84, p < .001), nursing professionals as occupation (OR = 2.12, 95% CI 1.55-2.90, p < .001), passive SLR angle (OR = 2.06, 95% CI 1.24-3.42, p = .005), abdominal muscle strength (OR = 1.61, 95% CI 1.07-2.41, p = .021), and gender (OR = 1.52, 95% CI 1.08-2.14, p = .015). CONCLUSION: In the future, it will be necessary to take preventive measures for risk factors and to follow up longitudinally on the prevalence of LBP and on workers with indicated risk factors.

Association Between Nondominant Leg-Side Hip Internal Rotation Restriction and Low Back Pain in Male Elite High School Soft Tennis Players.

CONTEXT: The incidence of low back pain (LBP) is high among high school male soft tennis players. In some sports for which the rotational component of the body is important, an association between restricted hip internal rotation of the nondominant leg and LBP has been reported; however, whether this association holds in soft tennis is unknown. Therefore, this study aimed to evaluate the association between hip internal rotation, hip external rotation, hamstring flexibility, iliopsoas flexibility, and LBP incidence. DESIGN: This study was designed as a cross-sectional study, conducted at a sports training center. METHODS: Participants comprised 113 male elite high school soft tennis players (age: 16.1 [0.7] y) from 9 elite-level teams. The main outcome measures were the hip internal and external rotation range of motion, hamstring flexibility on the straight leg raise test, and iliopsoas flexibility on the Thomas test. Multiple logistic regression analysis was performed to examine the influence of main outcomes on LBP incidence in the past 1 year. RESULTS: A total of 35 participants had LBP (LBP group); 78 participants did not have LBP (non-LBP group). Multiple logistic regression analysis revealed that the odds ratio for height was 1.08 (95% confidence interval, 1.00-1.16; P = .043) and for the hip internal rotation range of motion in the nondominant leg was 0.90 (95% confidence interval, 0.85-0.95; P < .001), indicating significant associations with LBP. CONCLUSION: Hip internal rotation range of motion in the nondominant leg and height were crucial factors related to LBP in male elite high school soft tennis players.

Gradual exacerbation of knee flexion angle after total knee arthroplasty in patients with diabetes mellitus.

OBJECTIVES: This study aimed to investigate the effect of diabetes mellitus (DM) on knee extension/flexion angle and its early clinical course after total knee arthroplasty (TKA). METHODS: Patients who received TKA were retrospectively divided into two groups based on haemoglobinA1c level; the DM group (23 knees) and the control group (23 knees matched for baseline characteristics). The passive knee extension/flexion angle, gait speed and Japanese Orthopaedic Association (JOA) score were evaluated preoperatively and at 1, 6 and 12 months postoperatively. RESULTS: There was no significant difference in the passive knee flexion angle at 1 and 6 months postoperatively between the groups (p = .302, p = .160, respectively). The passive knee flexion angle was significantly lower at 12 months postoperatively in the DM group than the control group (p = .014). In the DM group, the passive knee flexion angle at 6 and 12 months significantly decreased compared with that at 1 month postoperatively (p = .021, p < .001, respectively). There were no significant differences in the knee extension angle, gait speed and JOA score between the groups. CONCLUSION: Patients with DM are likely to experience passive knee flexion angle exacerbating from 1 to 6 months after TKA.

Suppression of cadmium uptake in rice using fermented bark as a soil amendment.

The contamination of rice paddies with heavy metals has become a serious concern due to their high toxicity to human health. In this study, we developed a chemical-free, fermented bark amendment (FBA) and used it for organic rice cultivation. The application of FBA resulted in the fixation of heavy metals, especially cadmium (Cd), in the soil and suppressed their uptake in brown rice. The suppression of Cd uptake was most effective, since its uptake in rice from FBA-supplemented soil was 10 times lower than that from untreated soil under ordinary water-filling conditions. These results could be explained by the rapid conversion of sulfate ions to sulfide ions, which subsequently react with Cd producing insoluble sulfide species, as well as Cd adsorption to the decomposed bark in soil. The FBA did not affect the uptake of metals, such as calcium and iron, which are necessary for the growth of rice. Thus, the FBA may suppress Cd uptake in rice, and its effectiveness is related to application time and water regime.