Analysis of the characteristics of anticipatory postural adjustments in older adults using smartphones: Association between cognitive and balance functions.

OBJECTIVES: Using smartphones, we aimed to clarify the characteristics of anticipatory postural adjustments (APA) in older adults and examine the relationship between cognitive and balance functions. METHODS: The study participants were 10 young and 13 older adults. An accelerometer built into a smartphone was attached to the lower back (L5) of the participant, and acceleration in the mediolateral direction was measured using a one-leg stance (OLS). As APA features, we analyzed the time to the peak value in the stance direction (peak latency [PL]) and the amount of displacement to the peak value in the stance direction (peak magnitude [PM]). Additionally, the measured PL was divided by PM for each group to obtain the APA ratio (APAr). We investigated the relationship between the APAr and Mini-BESTest subitems. RESULTS: Older adults showed delayed PL and decreased PM levels (p < 0.01). While in the Mini-BESTest sub-items, deductions were most common in the order of dual-task and single-leg standing, and most participants with low APAr scores were degraded in APA of sub-items. The correlation was observed between APAr and both TUG and dual-task cost (DTC) (r= -0.56, r= -0.67). According to the receiver operating characteristic curve, the APAr value was 1.71 in the older age group. CONCLUSIONS: Older adults showed delayed PL and decreased PM, and APAr was associated with cognitive and locomotor functions. By evaluating the APAr at the initiation of movement, it may be possible to distinguish the APA of the older adluts from the possible to the impossible of OLS movement.

Reliability and validity of quantitative evaluation of anticipatory postural adjustments using smartphones.

[Purpose] This study aimed to investigate the reliability and validity of the quantitative evaluation of anticipatory postural adjustments using smartphones. [Participants and Methods] The study included 10 young control participants who underwent a one-legged stance with an accelerometer and a smartphone that were simultaneously attached to their lower back (L5). Acceleration was measured as the mediolateral component of the lumbar movement toward the stance side. The peak value of the time (peak latency) and the amount of displacement (peak magnitude) in the stance side direction of the lumbar acceleration were analyzed as anticipatory postural adjustment features. Intra-rater reliability was calculated for both accelerometer and smartphone measurements, while inter-rater reliability was calculated for smartphone measurements by two examiners. Validity was determined for both accelerometer and smartphone measurements. [Results] In this study, the intra-rater reliability of the peak latency and peak magnitude in accelerometer and smartphone measurements was confirmed, as was the inter-rater reliability in smartphone measurements. The intra-rater reliability was confirmed through re-testing, while the validity of the accelerometer and smartphone measurements was also confirmed. [Conclusion] The findings of this study suggest that the use of smartphones to measure anticipatory postural adjustments is highly reliable and valid, making it a useful clinical balance index. The method is simple and can be used for continuous patient monitoring.

The reliability and validity of joint range of motion measurement using zoom and a smartphone application.

[Purpose] This study aimed to evaluate the reliability and validity of measuring the range of motion of joints using a remote videoconferencing system (Zoom) and a smartphone application. [Participants and Methods] This study included 16 young and healthy adults. The participants were instructed to perform shoulder joint flexion exercises in a seated position, with automatic motions, and maintain that posture throughout the measurement. Two measurements were performed: 1) angle measurement using a three-dimensional (3D) motion analyzer, and 2) angle measurement using the videoconference software, Zoom, and a smartphone application. Intra- and inter-rater reliabilities were calculated using the intraclass correlation coefficients (ICC). The degree of agreement between the representative values of each measurer and the 3D motion analyzer was examined. [Results] ICC (1, 1) for intra-examiner reliability were 0.912 and 0.996. For the inter-rater reliability, the ICC (2, 1) was 0.945. The correlation coefficient between each examiner's value and the value of the 3D motion analyzer was 0.955 and 0.980, respectively. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The method of remotely measuring joint range of motion using Zoom and a smartphone application demonstrated high reliability and validity.

Automated detection of anterior cruciate ligament tears using a deep convolutional neural network.

BACKGROUND: The development of computer-assisted technologies to diagnose anterior cruciate ligament (ACL) injury by analyzing knee magnetic resonance images (MRI) would be beneficial, and convolutional neural network (CNN)-based deep learning approaches may offer a solution. This study aimed to evaluate the accuracy of a CNN system in diagnosing ACL ruptures by a single slice from a knee MRI and to compare the results with that of experienced human readers. METHODS: One hundred sagittal MR images from patients with and without ACL injuries, confirmed by arthroscopy, were cropped and used for the CNN training. The final decision by the CNN for intact or torn ACL was based on the probability of ACL tear on a single MRI slice. Twelve board-certified physicians reviewed the same images used by CNN. RESULTS: The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the CNN classification was 91.0%, 86.0%, 88.5%, 87.0%, and 91.0%, respectively. The overall values of the physicians' readings were similar, but the specificity was lower than the CNN classification for some of the physicians, thus resulting in lower accuracy for the human readers. CONCLUSIONS: The trained CNN automatically detected the ACL tears with acceptable accuracy comparable to that of human readers.

Reliability of ultrasound to measure the distance between lumbar interspinous processes.

OBJECTIVES: This study aimed to determine the reliability of ultrasound to measure the distance between interspinous processes of the lumbar spine at the segmental level (i.e., L1-L2, L2-L3, L3-L4, and L4-L5). METHODS: Ten men with no history of orthopedic diseases or dysfunctions were included in this study. In total, 720 images of the lumbar spines of participants were analyzed (10 participants, 4 segments, 3 trials, 3 positions, 2 examiners). With participants in three different positions, images of each segment specifically focused on the distance between lumbar interspinous processes. Bland-Altman analysis (BAA) was used to determine intra- and inter-rater reliability. RESULTS: Intra-rater intraclass correlation coefficient (ICC) values (1, 1) were found to range from 0.840 to 0.988, whereas inter-rater ICC values (2, 1) ranged from 0.605 to 0.876. BAA results confirmed a fixed bias regarding the L4-L5 of the lumbar spine segment in the flexion position. CONCLUSIONS: Inter-rater reliability decreased throughout this study; however, results showed that using ultrasound to measure the distance between lumbar segmental interspinous processes could be applied in clinical settings to evaluate lumbar segmental mobility.

Possible role of MRI-detected osteophytes as a predictive biomarker for development of osteoarthritis of the knee: A study using data from the Osteoarthritis Initiative.

Objective: To elucidate the possible role of MRI-detected osteophytes as a predictive imaging biomarker for knee osteoarthritis (KOA). Design: Subjects (n â€‹= â€‹303) were selected according to the following inclusion criteria from the Osteoarthritis Initiative (OAI) data set: (1) â€‹< â€‹55 years old; (2) Western Ontario and McMaster Universities Arthritis Index pain score of 0; (3) Kellgren-Lawrence (KL) system grade 0 or 1; and (4) Complete MRI data set of the right knee. A pre-OA group (POA) consisted of subjects who developed KL grade 2 or more within 96 months, and a non-OA group (NOA) that remained KL 0 or 1 during that period. Baseline MRIs were assessed for osteophyte formation. Twenty-five locations were examined according to the MOAKS osteophyte score. Osteophytes at each location were assessed in terms of their predictive value for OA development. Results: Thirty-two subjects were POA and 271 were NOA. Age, BMI, and sex did not differ between the two groups. In the POA group, the number of subjects with osteophytes tended to be higher at all 25 sites. Forward stepwise regression analysis revealed five locations - medial patella, lateral intra-condylar notch of the femur, lateral femoral condyle, tibial spine, and lateral posterior condyle - were important for the prediction of KOA development. Having more than two osteophytes at these five locations predicted KOA development with a sensitivity of 0.75 and specificity of 0.79. Conclusions: MRI-detected osteophytes could serve as a predictive biomarker of KOA development within 96 months after detection.

Motor Function Relating to the Accuracy of Self-Overestimation Error in Community-Dwelling Older Adults.

Background: Older adults often overestimate their motor performance, which represents a serious safety hazard. The cause of this self-overestimation is to date, not yet fully established. Thus, the present study aimed to reveal the factors associated with self-overestimation by focusing on motor function. Methods: This study included 105 community-dwelling older adults [20 males, median (25, 75 percentile) age: 73.00 (69.50, 77.50)]. Participants were assessed for errors in their self-estimation using a two-step test. They estimated the two-step distance that could be reached with maximum effort. Thereafter, they performed the actual two-step action. Participants were comprehensively assessed for motor function by various tests (i.e., 10-meter Walking Test, Timed Up and Go Test, postural stability, and muscle strength). They were then divided into two groups (the self-underestimation or self-overestimation group) and their motor performances were compared. Multiple linear regression analysis was then utilized to investigate the relationship between self-estimation error and motor function. Results: Significant differences were found between the two groups regarding age, weight, actual two-step distance, and the time required for the Timed Up and Go Test and 10-meter Walking Test (p < 0.05). The regression analysis showed that self-estimation error was significantly related to the result of the 10-meter Walking Test (beta = 0.24, p = 0.011). Conclusions: The self-overestimation of motor performance, which is likely to lead to several dangers (i.e., falling or obstacle collision), was related to walking ability. Consequently, the results showed that the 10-meter Walking Test would assist in detecting the self-overestimation of motor performance.

Grit in Community-Dwelling Older Adults with Low Back Pain Is Related to Self-Physical Training Habits.

INTRODUCTION: Self-management is an effective way to manage chronic low back pain (LBP) and is frequently recommended. However, the psychological aspects, including grit (ie, perseverance and passion for long-term goals), of the habit of self-management remain unclear. OBJECTIVE: To investigate the relationship between grit and the self-directed exercise. DESIGN: Cross-sectional observational study. SETTING: Community-dwelling older adults. PARTICIPANTS: Fifty-nine older adults with LBP (30 men, 29 women; mean age 72 ± 5 years, range 65-82 years). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Primary outcome measures included grit scores on the Short Grit Scale and the number of months performing self-directed exercise. Correlation and multiple regression analyses were performed to determine the relationship between participants' grit and duration of self-directed exercise. RESULTS: A significant positive correlation between grit and the duration of self-directed exercise habits was observed (r = 0.49, P < .001). Furthermore, in multiple regression analysis, grit was a significant factor of the duration of self-directed exercise. CONCLUSION: Low grit was associated with reduced self-directed exercise in individuals with LBP self-directed exercise.

Correction: Motor planning error in Parkinson's disease and its clinical correlates.

[This corrects the article DOI: 10.1371/journal.pone.0202228.].

Isometric knee muscle strength measurement using a belt-stabilized hand-held dynamometer and an isokinetic dynamometer with and without trunk fixation: investigation of agreement of measurement values and factors influencing measurement.

[Purpose] The purpose of this study was to examine the agreement between the values obtained by using a hand-held dynamometer with a belt (belt-HHD) and an isokinetic dynamometer (IKD) for the measurement of isometric knee flexion and extension muscle strength. We also studied the factors influencing the measurement. [Participants and Methods] Overall, 26 healthy young adults (16 males, 10 females) participated in the study; the mean age was 21 years. Knee flexion and extension muscle strength were measured by three methods: 1) belt-HHD, 2) conventional IKD with the participant sitting on an attached chair (conv-IKD), and 3) modified IKD with the participant sitting on the same mat table as HHD (mod-IKD). [Results] In the measurement of knee extension, mod-IKD and conv-IKD showed a fixed bias and a proportional bias, conv-IKD and belt-HHD showed a fixed bias, and belt-HHD and mod-IKD showed a fixed bias. In the measurement knee flexion, conv-IKD and mod-IKD showed a proportional bias, belt-HHD and conv-IDK showed a fixed bias, and mod-IKD and belt-HHD showed a fixed bias. In each combination, the measured values were larger in the latter due to errors. However, the types and values of errors differed when analysis was conducted based on gender. [Conclusion] In order to increase the agreement between the values, it is necessary to revise the fixing method of the trunk, and the fixing method of the belt and the sensor pad in belt-HHD.

Efficacy of Verbally Describing One's Own Body Movement in Motor Skill Acquisition.

The present study examined whether (a) verbally describing one's own body movement can be potentially effective for acquiring motor skills, and (b) if the effects are related to motor imagery. The participants in this study were 36 healthy young adults (21.2 ± 0.7 years), randomly assigned into two groups (describing and control). They performed a ball rotation activity, with the describing group being asked by the examiner to verbally describe their own ball rotation, while the control group was asked to read a magazine aloud. The participants' ball rotation performances were measured before the intervention, then again immediately after, five minutes after, and one day after. In addition, participants' motor imagery ability (mental chronometry) of their upper extremities was measured. The results showed that the number of successful ball rotations (motor smoothness) and the number of ball drops (motor error) significantly improved in the describing group. Moreover, improvement in motor skills had a significant correlation with motor imagery ability. This suggests that verbally describing an intervention is an effective tool for learning motor skills, and that motor imagery is a potential mechanism for such verbal descriptions.

Effectiveness of using an unskilled model in action observation combined with motor imagery training for early motor learning in elderly people: a preliminary study.

AIM OF THE STUDY: To investigate a more available model for the early phase of motor learning after action observation combined with motor imagery training in elderly people. To address the purpose, we focused on a slow, unskilled model demonstrating an occasional error. MATERIALS AND METHODS: A total of 36 elderly people participated in the current study and were assigned to either the unskilled or skilled model observation groups (n = 12, respectively), or the control group (n = 12). The participants in the observation groups observed the assigned a video clip of an unskilled or skilled model demonstrating a ball rotation task. During the observation, the participants were instructed to imagine themselves as the person in the video clip. The participants in the control group read a scientific paper during the equivalent period of action observation and motor imagery. We measured ball rotation performance (the time required for five rotations, the number of ball drops) in pre- and post-intervention (observation combined with motor imagery training for intervention groups or reading for control group). RESULTS: Ball rotation performance (ball rotation speed) significantly improved in the unskilled model observation group compared to the other two groups. CONCLUSIONS: Intervention for action observation using unskilled model combined with motor imagery was effective for improving motor performance during the early phase of motor learning.

Motor planning error in Parkinson's disease and its clinical correlates.

This study aimed to investigate (a) motor planning difficulty by using a two-step test in Parkinson's disease (PD) compared with age-matched healthy subjects and (b) the relationship between motor planning difficulty and clinical factors. The two-step test was performed by 58 patients with PD with Hoehn & Yahr (H&Y) stage I-IV and 110 age-matched healthy older adult controls. In the two-step test, the participants estimated the two-step distance with maximum effort. Subsequently, they performed the actual two-step trial to measure the actual maximum distance. We calculated the accuracy of the estimation (estimated distance minus actual distance). In both groups, subjects who estimated >5 cm were defined as the overestimation group, and those who estimated <5 cm over- and underestimation were defined as the non-overestimation group. The overestimation group consisted of 17 healthy older adults (15.5%) and 23 patients with PD (39.7%). The number of patients with PD with overestimation was significantly more than that of healthy controls by Chi-squared test. H&Y stage and the Unified Parkinson's Disease Rating Scale (UPDRS) part II and III scores in overestimation group in PD patients were significantly higher than those in overestimation group in PD patients. Moreover, multiple regression using H&Y stage and UPDRS parts II and III as independent variables showed that the UPDRS part II score was the only related factor for the estimation error distance. Estimation error distance was significant correlated with UPDRS parts II and III. Patients with PD easily have higher rates of motor-related overestimation than age-matched healthy controls. In addition, UPDRS parts II and III expressed ability of activities of daily living and motor function as influences on motor-related overestimation. Particularly, multiple regression indicated that UPDRS part II directly showed the ability of daily living as an essential factor for overestimation.

Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements.

[Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person.

Reliability and validity of an ultrasound-based imaging method for measuring interspinous process distance in the lumbar spine using two different index points.

[Purpose] This study assessed the reliability and validity of an ultrasound-based imaging method for measuring the interspinous process distance in the lumbar spine using two different index points. [Subjects and Methods] Ten healthy males were recruited. Five physical therapy students participated in this study as examiners. The L2-L3 interspinous distance was measured from the caudal end of the L2 spinous process to the cranial end of the L3 spinous process (E-E measurement) and from the top of the L2 spinous process to the top of the L3 spinous process (T-T measurement). Intraclass correlation coefficients were calculated to estimate the relative reliability. Validity was assessed using a model resembling the living human body. [Results] The reliability study showed no difference in intra-rater reliability between the two measurements. However, the E-E measurement showed higher inter-rater reliability than the T-T measurement (Intraclass correlation coefficients: 0.914 vs. 0.725). Moreover, the E-E measurement method had good validity (Intraclass correlation coefficients: 0.999 and 95% confidence interval for minimal detectable change: 0.29 mm). [Conclusion] These results demonstrate the high reliability and validity of ultrasound-based imaging in the quantitative assessment of lumbar interspinous process distance. Of the two methods, the E-E measurement method is recommended.

An effective model for observational learning to improve novel motor performance.

[Purpose] To investigate whether for observational learning involving a ball rotation task, an unskilled model showing clumsy finger movements is more effective than a skilled model . [Subjects and Methods] Thirty-six young adults were randomly assigned to one of three groups. The unskilled model observation group observed a video of a ball rotation task practiced by a person for a short time. The skilled model observation group observed another video of the same task practiced by the person for a relatively long time. The non-observation group did not observe any video. Regarding rotation speed, the unskilled model was faster than the participants' but slower than the skilled model. The unskilled model had the highest number of ball drops. [Results] After the observation, the unskilled model observation group showed significantly faster rotation speed than the other groups. There were no significant differences between the groups in the number of ball drops. [Conclusion] An unskilled model whose performance is better than the participants' is beneficial for improving motor performance but a model showing less skill than the participants is not.