Muscle synergy and kinematic synergy analyses during sit-to-stand motions in hallux valgus patients before and after treatment with Kinesio taping.

OBJECTIVES: To explore the impact of hallux valgus (HV) on lower limb neuromuscular control strategies during the sit-to-stand (STS) movement, and to evaluate the effects of Kinesio taping (KT) intervention on these control strategies in HV patients. METHODS: We included 14 young healthy controls (HY), 13 patients in the HV group (HV), and 11 patients in the HV group (HVI) who underwent a Kinesio taping (KT) intervention during sit-to-stand (STS) motions. We extracted muscle and kinematic synergies from EMG and motion capture data using non-negative matrix factorization (NNMF). In addition, we calculated the center of pressure (COP) and ground reaction forces (GRF) to assess balance performance. RESULTS: There were no significant differences in the numbers of muscle and kinematic synergies between groups. In the HV group, knee flexors and ankle plantar flexors were abnormally activated, and muscle synergy D was differentiated. Muscle synergy D was not differentiated in the HVI group. CONCLUSION: Abnormal activation of knee flexors and plantar flexors led to the differentiation of module D in HV patients, which can be used as an indicator of the progress of HV rehabilitation. KT intervention improved motor control mechanisms in HV patients.

Bioelectrical impedance phase angle combined with physical function predicts pre-frailty in maintenance hemodialysis patients: a prospective study.

BACKGROUND: The prevalence of pre-frailty is notably high among maintenance hemodialysis (MHD) patients. Pre-frailty, an early and reversible condition between non-frailty and frailty, can lead to adverse outcomes such as increased unplanned hospital admissions and a higher risk of other chronic diseases. Early identification and intervention of pre-frailty in MHD patients are crucial. This study aimed to establish a simple and effective model for screening and identifying MHD patients at high risk of pre-frailty by using 50 kHz-Whole Body Phase Angle (PhA) measured by bioelectrical impedance analysis (BIA), hand grip strength (HGS), the Five-Times-Sit-to-Stand Test (FTSST), and laboratory parameters, with a specific focus on gender differences. METHODS: This prospective cross-sectional study was conducted from September to December 2023 at the Wenjiang Hemodialysis Center in the Department of Nephrology, West China Hospital, Sichuan University, Chengdu, China. A total of 244 MHD patients, including 130 males and 114 females, were enrolled, comprising 128 non-frail and 116 pre-frail individuals. Data were collected prospectively, including demographic information, physical measurements, and laboratory test results. All participants provided informed consent before enrollment. The FRAIL scale (FS) was used to assess pre-frailty in MHD patients. Grip strength was measured using an electronic grip strength tester, physical function was assessed using the Five-Times-Sit-to-Stand Test, and whole-body phase angle was measured using the InBody S10 device. RESULTS: A total of 244 MHD patients with a mean age of 53.75 ± 0.90 years were enrolled, including 130 males with a mean age of 54.12 ± 1.26 years and 114 females with a mean age of 53.32 ± 1.29 years. ROC curve analysis showed that in male patients, the AUC of PhA for predicting pre-frailty was 0.919, with a sensitivity of 94.5% and specificity of 91.3%, and a cutoff value of 6.05°; in female patients, the AUC of PhA was 0.870, with a sensitivity of 70.5% and specificity of 90.6%, and a cutoff value of 5.25°. The AUC of FTSST for screening pre-frailty in male patients was 0.827, with a sensitivity of 62.3% and specificity of 96.2%, and a cutoff value of 12.95 s; in female patients, the AUC of FTSST was 0.784, with a sensitivity of 67.3% and specificity of 84.0%, and a cutoff value of 12.95 s. Additionally, in male patients, the combination of PhA and FTSST resulted in an AUC of 0.930, with a sensitivity of 96.4% and specificity of 81.3%; in female patients, the AUC was 0.911, with a sensitivity of 78.7% and specificity of 92.5%. CONCLUSION: PhA measured by BIA, in combination with the Five-Times-Sit-to-Stand Test, serves as an effective screening tool and predictor of pre-frailty in MHD patients. The combination of PhA and FTSST shows enhanced diagnostic value in female patients, while PhA alone is sufficient for predicting pre-frailty in male patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100051111), registered on 2021-09-13.

The 1-min sit-to-stand test induces a significant and reliable level of neuromuscular fatigability: insights from a mobile app analysis.

PURPOSE: The performance metric associated with the execution of the 1-min sit-to-stand (1STS) typically relies on the number repetitions completed in 1 min. This parameter presents certain limitations (e.g., ceiling effect, motivational factors) which can impede its interpretation. Introducing additional parameters, such as neuromuscular fatigability level, could enhance the informative value of the 1STS and facilitate its interpretation. This study aimed to assess (i) whether the 1STS induces fatigability and (ii) the reliability of the fatigability level. METHODS: Forty young, healthy, and active participants underwent the 1STS twice during the same session. Isolated sit-to-stand maneuvers were performed before, immediately, and 1 min after completing the 1STS. A mobile app was utilized to obtain time (STST), velocity (STSV), and muscle power (STSP) from these sit-to-stand maneuvers. The pre-post change in these parameters served as the fatigability marker. Reliability was assessed using the intra-class correlation coefficient (ICC) and the coefficient of variation (CV). RESULTS: The mean number of repetitions during the 1STS was 63 ± 9. Significant decline in performance was observed for STST (13 ± 8%), STSV (-11.2 ± 6%), and STSP (-5.2 ± 3%), with more than 74% of participants exhibiting a decline beyond the minimal detectable change. Excellent between-session reliability (ICC ≥ 0.9; CV ≤ 5.3) was observed for the mobile app variables. CONCLUSION: The 1STS induces significant levels of fatigability. The fatigability indicators derived from the mobile app demonstrated remarkable reliability. Utilizing this user-friendly interface for computing fatigability may empower professionals to acquire insightful complementary indicators from the 1STS.

Predictive value of the five-repetition sit-to-stand test for outcomes after surgery for lumbar disc herniation: prospective study.

OBJECTIVE: It is unknown whether presence of pre-operative objective functional impairment (OFI) can predict post-operative outcomes in patients with lumbar disc herniation (LDH). We aimed to determine whether pre-operative OFI measured by the five-repetition sit-to-stand test (5R-STS) could predict outcomes at 12-months post-discectomy. METHODS: Adult patients with LDH scheduled for surgery were prospectively recruited from a Dutch short-stay spinal clinic. The 5R-STS time and patient reported outcome measures (PROMs) including Oswestry Disability Index, Roland-Morris Disability Questionnaire, Visual Analogue Scale (VAS) for back and leg pain, EQ-5D-3L health-related quality of life, EQ5D-VAS and ability to work were recorded pre-operatively and at 12-months. A 5R-STS time cut-off of ≥ 10.5 s was used to determine OFI. Mann-Whitney and Chi-square tests were employed to determine significant differences in post-operative outcomes between groups stratified by presence of pre-operative OFI. RESULTS: We recruited 134 patients in a prospective study. Twelve-month follow-up was completed by 103 (76.8%) patients. Mean age was 53.2 ± 14.35 years and 50 (48.5%) patients were female. Pre-operatively, 53 (51.5%) patients had OFI and 50 (48.5%) did not. Post-operatively, patients with OFI experienced a significantly greater mean change (p < 0.001) across all PROMs compared to patients without OFI, except leg pain (p = 0.176). There were no significant differences in absolute PROMs between groups at 12-months (all p > 0.05). CONCLUSIONS: The presence of OFI based on 5R-STS time does not appear to decrease a patient's likelihood of experiencing satisfactory post-operative outcomes. The 5R-STS cannot predict how a patient with LDH will respond to surgery at 12-month follow-up.

Sit-to-stand performance in children with cerebral palsy: a population-based cross-sectional study.

BACKGROUND: Sit-to-stand (STS) is one of the most commonly performed functional movements in a child's daily life that enables the child to perform functional activities such as independent transfer and to initiate walking and self-care. Children with cerebral palsy (CP) often have reduced STS ability. The aim of this study was to describe STS performance in a national based total population of children with CP and its association with age, sex, Gross Motor Function Classification System (GMFCS) level, and CP subtype. METHODS: This cross-sectional study included 4,250 children (2,503 boys, 1,747 girls) aged 1-18 years from the Swedish Cerebral Palsy Follow-Up Program (CPUP). STS performance was classified depending on the independence or need for support into "without support," "with support," or "unable." "With support" included external support from, e.g., walls and furniture. Physical assistance from another person was classified as "unable" (dependent). Ordinal and binary logistic regression analyses were used to identify associations between STS and age, GMFCS level, and CP subtype. RESULTS: 60% of the children performed STS without support, 14% performed STS with support, and 26% were unable or needed assistance from another person. STS performance was strongly associated with GMFCS level and differed with age and subtype (p < 0.001). For all GMFCS levels, STS performance was lowest at age 1-3 years. Most children with GMFCS level I (99%) or II (88%) performed STS without support at the age of 4-6 years. In children with GMFCS level III or IV, the prevalence of independent STS performance improved throughout childhood. CP subtype was not associated with STS performance across all GMFCS levels when adjusted for age. CONCLUSIONS: Independent STS performance in children with CP is associated with GMFCS level and age. Children with CP acquire STS ability later than their peers normally do. The proportion of children with independent STS performance increased throughout childhood, also for children with GMFCS level III or IV. These findings suggest the importance of maintaining a focus on STS performance within physiotherapy strategies and interventions for children with CP, including those with higher GMFCS level.

Biomechanics of the lower limb in patients with mild knee osteoarthritis during the sit-to-stand task.

BACKGROUND: Knee osteoarthritis (KOA) is a prevalent and debilitating condition that markedly affects the sit-to-stand (STS) activity of patients, a prerequisite for daily activities. Biomechanical recognition of movements in patients with mild KOA is currently attracting attention. However, limited studies have been conducted solely on the observed differences in sagittal plane movement and muscle activation. AIM: This study aimed to identify three-dimensional biomechanical and muscle activation characteristics of the STS activity in patients with mild KOA. METHODS: A cross-sectional study was conducted to observe the differences between patients with mild KOA and a control group (CG). It was conducted to observe the differences in muscle activation, including root mean square (RMS%) and integrated electromyography (items), kinematic parameters like range of motion (ROM) and maximum angular velocity, as well as dynamic parameters such as joint moment and vertical ground reaction force (vGRF). RESULTS: Patients with mild KOA had a higher body mass index and longer task duration. In the sagittal plane, patients with KOA showed an increased ROM of the pelvic region, reduced ROM of the hip-knee-ankle joint, and diminished maximum angular velocity of the knee-ankle joint. Furthermore, patients with KOA displayed increased knee-ankle joint ROM in the coronal plane and decreased ankle joint ROM in the horizontal plane. Integrated vGRF was higher in both lower limbs, whereas the vGRF of the affected side was lower. Furthermore, patients showed a decreased peak adduction moment (PADM) and increased peak external rotation moment in the knee joint and smaller PADM and peak internal rotation moment in the ankle joint. The affected side exhibited decreased RMS% and iEMG values of the gluteus medius, vastus medialis, and vastus lateralis muscles, as well as a decreased RMS% of the rectus femoris muscle. Conversely, RMS% and iEMG values of the biceps femoris, lateral gastrocnemius, and medial gastrocnemius muscles were higher. CONCLUSION: The unbalanced activation characteristics of the anterior and posterior muscle groups, combined with changes in joint moment in the three-dimensional plane of the affected joint, may pose a potential risk of injury to the irritated articular cartilage.

Construction of an instrument to enable the assessment of the risk of falls in older outpatients: A quantitative methodological study.

OBJECTIVES: To develop an instrument to facilitate the risk assessment of falls in older outpatients. DESIGN: A quantitative methodological study using the cross-sectional data. METHODS: This study enrolled 1988 older participants who underwent comprehensive geriatric assessment (CGA) in an outpatient clinic from May 2020 to November 2022. The history of any falls (≥1 falls in a year) and recurrent falls (≥2 falls in a year) were investigated. Potential risk factors of falls were selected by stepwise logistic regression, and a screening tool was constructed based on nomogram. The tool performance was compared with two reference tools (Fried Frailty Phenotype; CGA with 10 items, CGA-10) by using receiver operating curves, sensitivity (Sen), specificity (Spe), and area under the curve (AUC). RESULTS: Age, unintentional weight loss, depression measured by the Patient Health Questionnaire-2, muscle strength measured by the five times sit-to-stand test, and stand balance measured by semi- and full-tandem standing were the most important risk factors for falls. A fall risk screening tool was constructed with the six measurements (FRST-6). FRST-6 showed the best AUC (Sen, Spe) of 0.75 (Sen = 0.72, Spe = 0.69) for recurrent falls and 0.65 (Sen = 0.74, Spe = 0.48) for any falls. FRST-6 was comparable to CGA-10 and outperformed FFP in performance. CONCLUSIONS: Age, depression, weight loss, gait, and balance were important risk factors of falls. The FRST-6 tool based on these factors showed acceptable performance in risk stratification. IMPACT: Performing a multifactorial assessment in primary care clinics is urgent for falls prevention. The FRST-6 provides a simple and practical way for falls risk screening. With this tool, healthcare professionals can efficiently identify patients at risk of falling and make appropriate recommendations in resource-limited settings. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution was received, due to our study design.

MocapMe: DeepLabCut-Enhanced Neural Network for Enhanced Markerless Stability in Sit-to-Stand Motion Capture.

This study examined the efficacy of an optimized DeepLabCut (DLC) model in motion capture, with a particular focus on the sit-to-stand (STS) movement, which is crucial for assessing the functional capacity in elderly and postoperative patients. This research uniquely compared the performance of this optimized DLC model, which was trained using 'filtered' estimates from the widely used OpenPose (OP) model, thereby emphasizing computational effectiveness, motion-tracking precision, and enhanced stability in data capture. Utilizing a combination of smartphone-captured videos and specifically curated datasets, our methodological approach included data preparation, keypoint annotation, and extensive model training, with an emphasis on the flow of the optimized model. The findings demonstrate the superiority of the optimized DLC model in various aspects. It exhibited not only higher computational efficiency, with reduced processing times, but also greater precision and consistency in motion tracking thanks to the stability brought about by the meticulous selection of the OP data. This precision is vital for developing accurate biomechanical models for clinical interventions. Moreover, this study revealed that the optimized DLC maintained higher average confidence levels across datasets, indicating more reliable and accurate detection capabilities compared with standalone OP. The clinical relevance of these findings is profound. The optimized DLC model's efficiency and enhanced point estimation stability make it an invaluable tool in rehabilitation monitoring and patient assessments, potentially streamlining clinical workflows. This study suggests future research directions, including integrating the optimized DLC model with virtual reality environments for enhanced patient engagement and leveraging its improved data quality for predictive analytics in healthcare. Overall, the optimized DLC model emerged as a transformative tool for biomechanical analysis and physical rehabilitation, promising to enhance the quality of patient care and healthcare delivery efficiency.

A Clustering-Based Approach to Functional and Biomechanical Parameters Recorded with a Pair of Smart Eyeglasses in Older Adults in Order to Determine Physical Performance Groups.

Falls and frailty status are often associated with a decline in physical capacity and multifactorial assessment is highly recommended. Based on the functional and biomechanical parameters measured during clinical tests with an accelerometer integrated into smart eyeglasses, the purpose was to characterize a population of older adults through an unsupervised analysis into different physical performance groups. A total of 84 participants (25 men and 59 women) over the age of sixty-five (age: 74.17 ± 5.80 years; height: 165.70 ± 8.22 cm; body mass: 68.93 ± 13.55 kg) performed a 30 s Sit-to-Stand test, a six-minute walking test (6MWT), and a 3 m Timed Up and Go (TUG) test. The acceleration data measured from the eyeglasses were processed to obtain six parameters: the number of Sit-to-Stands, the maximal vertical acceleration values during Sit-to-Stand movements, step duration and length, and the duration of the TUG test. The total walking distance covered during the 6MWT was also retained. After supervised analyses comparison (i.e., ANOVAs), only one of the parameters (i.e., step length) differed between faller groups and no parameters differed between frail and pre-frail participants. In contrast, unsupervised analysis (i.e., clustering algorithm based on K-means) categorized the population into three distinct physical performance groups (i.e., low, intermediate, and high). All the measured parameters discriminated the low- and high-performance groups. Four of the measured parameters differentiated the three groups. In addition, the low-performance group had a higher proportion of frail participants. These results are promising for monitoring activities in older adults to prevent the decline of physical capacities.

Accuracy Validation of a Sensor-Based Inertial Measurement Unit and Motion Capture System for Assessment of Lower Limb Muscle Strength in Older Adults-A Novel and Convenient Measurement Approach.

(1) Background: The aim of this study was to assess lower limb muscle strength in older adults during the transfer from sitting to standing (STS) using an inertial measurement unit (IMU). Muscle weakness in this population can severely impact function and independence in daily living and increase the risk of falls. By using an IMU, we quantified lower limb joint moments in the STS test to support health management and individualized rehabilitation program development for older adults. (2) Methods: This study involved 28 healthy older adults (13 males and 15 females) aged 60-70 years. The lower limb joint angles and moments estimated using the IMU were compared with a motion capture system (Mocap) (pair t-test, ICC, Spearman correlations, Bland-Altman plots) to verify the accuracy of the IMU in estimating lower limb muscle strength in the elderly. (3) Results: There was no significant difference in the lower limb joint angles and moments calculated by the two systems. Joint angles and moments were not significantly different (p > 0.05), and the accuracy and consistency of the IMU system was comparable to that of the Mocap system. For the hip, knee, and ankle joints, the ICCs for joint angles were 0.990, 0.989, and 0.885, and the ICCs for joint moments were 0.94, 0.92, and 0.89, respectively. In addition, the results of the two systems were highly correlated with each other: the r-values for hip, knee, and ankle joint angles were 0.99, 0.99, and 0.96, and the r-values for joint moments were 0.92, 0.96, and 0.85. In the present study, there was no significant difference (p > 0.05) between the IMU system and the Mocap system in calculating lower limb joint angles and moments. (4) Conclusions: This study confirms the accuracy of the IMU in assessing lower limb muscle strength in the elderly. It provides a portable and accurate alternative for the assessment of lower limb muscle strength in the elderly.

Sensor-Integrated Chairs for Lower Body Strength and Endurance Assessment.

This paper describes an automated method and device to conduct the Chair Stand Tests of the Fullerton Functional Test Battery. The Fullerton Functional Test is a suite of physical tests designed to assess the physical fitness of older adults. The Chair Stand Tests, which include the Five Times Sit-to-Stand Test (5xSST) and the 30 Second Sit-to-Stand Test (30CST), are the standard for measuring lower-body strength in older adults. However, these tests are performed manually, which can be labor-intensive and prone to error. We developed a sensor-integrated chair that automatically captures the dynamic weight and distribution on the chair. The collected time series weight-sensor data is automatically uploaded for immediate determination of the sit-to-stand timing and counts, as well as providing a record for future comparison of lower-body strength progression. The automatic test administration can provide significant labor savings for medical personnel and deliver much more accurate data. Data from 10 patients showed good agreement between the manually collected and sensor-collected 30CST data (M = 0.5, SD = 1.58, 95% CI = 1.13). Additional data processing will be able to yield measurements of fatigue and balance and evaluate the mechanisms of failed standing attempts.

The five times sit-to-stand test predicts same-day discharge for outpatients undergoing total joint arthroplasty.

PURPOSE: To examine whether a patient's pre-operatively administered five times sit-to-stand (FTSTS) test score, when used alone or when combined with previously established predictors, relates to same-day discharge (SDD) after total knee or hip arthroplasty. METHODS: This study utilized a multivariate, retrospective, observational design. Electronic medical record data for included participants were used to analyze the relationship between the patient factors (including the novel FTSTS variable) and the SDD outcome. Univariate and multiple variable regression modeling was undertaken to understand the strength of the relationship between the independent variables with the dependent variable. Receiver operating curve (ROC) analysis was performed to determine the area under the curve (AUC) for the novel model. Cut score analysis was performed to establish the score which has the greatest utility for stratifying patients based upon their likelihood of achieving SDD. RESULTS: All independent variables related to the SDD outcome with varying effect sizes. The dichotomized FTSTS score related to the SDD outcome with medium effect (Exp(B) = 2.56). The score of 13.6 s was established as the point where the test was most highly sensitive and specific. The combined model including all included patient characteristics had a classification accuracy of 64.7% and an area under the curve score of .724. CONCLUSION: The FTSTS score had higher predictive accuracy than all other stand-alone patient characteristics for the SDD outcome.

The one-minute sit-to-stand test: A practical tool for assessing functional exercise capacity in patients with COPD in routine clinical practice.

Background: Chronic obstructive pulmonary disease (COPD) is associated with a reduced exercise capacity. Although several field tests for exercise capacity have been modified for non-standard settings, i.e. outside the hospital clinic or pulmonary rehabilitation center, their uptake remains limited. Objectives: To assess the test-retest reliability, constuct validity and responsiveness of the one-minute sit-to-stand test (1'STST) adopted in clinical practice among patients with COPD and to confirm the earlier established minimal important difference (MID) of three repetitions. Methods: Patients with COPD performed two 1'STSTs, two 6-minute walk tests (6MWT), an isometric quadriceps force (QF) measurement, a cardiopulmonary exercise test (CPET), and a seven-day physical activity (PA) measurement before and after three months of pulmonary rehabilitation (PR). An Intraclass Correlation Coefficient (ICC) evaluated the agreement between two 1'STSTs. Pearson Correlation examined the association between the 1'STST and other physical measurements, and their changes following PR. A receiver operating characteristic (ROC) curve was constructed using a 30-meter increment in the 6MWT as cut-off to identify responders. Results: The 1'STST demonstrated good reliability (Δ0.9 ± 4.0 repetitions, p = .13; ICC = 0.79). The 1'STST was moderately correlated with the 6MWT (r = 0.57, p < .0001), VO2max (r = 0.50, p = .0006) and maximal work rate (r = 0.52, p = .0003). Weak correlations were observed with QF (r = 0.33, p = .03) and step count (r = 0.38, p = .013). The 1'STST improved after PR (∆ = 3.6 ± 6.4 repetitions, p = .0013) and changes correlated moderately with changes in the 6MWT (r = 0.57, p = .002), QF (r = 0.48, p = .003) and VO2max (r = 0.41, p = .014). A cut-off of three repetitions demonstrated a 71% accuracy in identifying responders to a rehabilitation program. Conclusion: The 1'STST is a valuable alternative to evaluate exercise capacity in patients with COPD when more expensive and time-consuming tests are unavailable.

Taiwanese reference values for the Short Physical Performance Battery in community-dwelling older adults.

OBJECTIVES: To establish reference values for SPPB score as well as test performances among Taiwanese community-dwelling older adults. METHODS: Participants included 847 older adults. The total scores and three subtest scores for the SPPB and the registered time to complete the walk and five-repetition sit-to-stand (STS) tests were determined and compared between sex and age (65-74, 75-84, and ≥85 years) groups. RESULTS: The mean SPPB total score was 10.9 in women and 10.5 in men. SPPB scores did not differ by sex, regardless of age group. However, the walk test (p = .030) and STS test (p = .008) timings were longer for men than for women in the 65-74-year-old group. The ≥85-year-old men achieved a lower balance score than did the 65-74-year-old men (p = .027). CONCLUSIONS: Population-specific SPPB reference values contribute to assessments of physical function and facilitate cross-cultural comparisons of physical performance.

Effect of coaching the sit-to-stand motion and attentional focus.

[Purpose] The present study investigated whether (1) "standing up while bowing" is effective for promoting the sit-to-stand (STS) motion and (2) whether this coaching promotes internal focus. [Participants and Methods] The participants included 17 healthy adults who performed the 30-s chair stand test with two sets of verbal instructions. The verbal instructions were as follows: "Please stand up as many times as possible for 30 s" (control condition) and "Please stand up while bowing as many times as possible for 30 s" (bowing condition). The participants performed the tests successively under the two conditions. In the 30-s chair stand test, a three-axis accelerometer was attached to the participants and the sagittal STS motion was filmed using a video camera. After the 30-s chair stand test, we used the modified Movement-Specific Reinvestment Scale (MSRS) to evaluate attentional focus. Differences in the measurements were analyzed using the Wilcoxon signed-rank test or paired t-test for each condition. [Results] Statistical analysis revealed significant differences in the CS-30 count, time from sitting to standing, time from sitting to lift-off, time from lift-off to standing, and the trunk tilt angle on lift-off. Regarding the questionnaire, Statistical analysis revealed significant differences in the MSRS and "conscious motor processing". [Conclusion] These results suggest that "standing up while bowing" has limited effectiveness in promoting the STS motion because the coaching promotes internal focus.

Cut-off values of one-minute sit-to-stand test for determining physical performance in mild-post-COVID-19 individuals.

Background: This study aims to establish cutoff values for the one-minute sit-to-stand test (1STST) to predict physical performance in mild-post- coronavirus disease 2019 (COVID-19) individuals and to compare the 1STST with the 6-minute walk test (6MWT) in assessing hemodynamic response and to explore the correlation between 1STST, 6MWT, and muscle strength, including leg and respiratory muscle strength. Methods: A cross-sectional study of 93 participants with mild post-COVID-19 symptoms was conducted. Sociodemographic and anthropometric data were collected, and pulmonary function, as well as respiratory and quadriceps muscle strength, were evaluated. Functional capacity was assessed using the 6MWT and 1STST. Additionally, hemodynamic responses, fatigue, and dyspnea were measured before and after each test. Results: The cutoff for the 1STST in mild post-COVID-19 individuals was ≥29 repetitions, with an AUC of 0.84, sensitivity of 80.52%, and specificity of 75.00%. The 1STST resulted in higher heart rate, systolic blood pressure, and dyspnea compared to the 6MWT, and showed a significant moderate correlation with the 6MWT (r = 0.532, p < 0.0001) and weak correlations with leg strength and respiratory muscle strength. Conclusion: A cutoff of less than 29 repetitions on the 1STST indicates functional impairment in mild post-COVID-19 cases, as it induces greater physiological stress than the 6MWT and correlates with muscle strength, making it crucial for rehabilitation assessment.

Older adults with slow sit to stand times show reduced temporal precision of audio-visual integration.

Sustained integration of sensory inputs over increased temporal delays is associated with reduced cognitive and physical functioning in older adults and adverse outcomes such as falls. Here, we explored the relationship between multisensory integration and a clinically relevant measure of balance/postural control; Sit-to-Stand Time, the efficiency with which an older adult can transition between a seated and a standing posture. We investigated whether temporal multisensory integration was associated with performance on the Five-Times Sit-to-Stand Test (FTSST) in a large sample of 2556 older adults (mean age = 63.62 years, SD = 7.50; 55% female) drawn from The Irish Longitudinal Study on Ageing (TILDA). K-means clustering was applied to FTSST data, yielding three clusters characterised by fast (mean = 10.88 s; n = 1122), medium (mean = 14.34 s; n = 1133) and slow (mean = 18.97 s; n = 301) sit-to-stand times. At wave 3 of TILDA, older adults participated in the Sound Induced Flash Illusion (SIFI), a measure of the precision of temporal audio-visual integration, which included three audio-visual stimulus onset asynchronies (SOAs): 70, 150 and 230 ms. Older adults with the slowest sit-to-stand times were more susceptible to the SIFI at the longest SOA (230 ms) compared to the shortest SOA (70 ms) relative to those with the fastest times (p = 0.02). Older adults who take longer to repeatedly transition from a seated to a standing posture exhibit an expanded temporal binding window for audio-visual events, supporting a link between multisensory perception and balance/postural control in ageing.

Determination of five times-sit-to-stand test performance in patients with multiple sclerosis: validity and reliability.

PURPOSE/AIM: Although Five Times-Sit-To-Stand test (FTSST) performance is known to be a valid and reliable method in people with chronic stroke, Parkinson's disease, and balance disorder, it has not been widely studied in patients with Multiple sclerosis (MS). The main aim of this study was to evaluate validity and reliability of the FTSST in patients with MS. METHODS: The first outcome measure of the study was the FTSST, which was conducted by two different researchers. Secondary outcome measures were Biodex Stability System (BSS), 10-meter walk test, time up go test (TUG), EDSS scoring, Fatigue Severity Scale (FSS), Barthel Index, Quadriceps Muscle strength test, Functional Reach test. Intraclass correlation coefficient (ICC) was used for the validity and reliability of the FTSST, which was made by two different researchers, and Pearson Correlation Analysis was used to determine its relationship with other measurements. RESULTS: Interrater and test-retest reliability for the FTSST were excellent (Intraclass correlation coefficients of 0.98 and 0.99, respectively). A statistically significant correlation was found between all secondary outcome measures and FTSST (p < 0.05). CONCLUSION: FTSST is considered to be a valid, reliable, easy, and rapid method for evaluating lower extremity muscle strength and balance in patients with MS.

The effects of standardised versus individualised seat height on 1-minute sit-to-stand test performance in healthy individuals: a randomised crossover trial.

PURPOSE: We aimed to (i) investigate differences in 1-minute sit-to-stand test (1MSTST) performance (i.e., the number of repetitions) between a standardised modality (i.e., starting from a conventional chair with 46 cm seat height) and an individualised modality (i.e., starting with a knee joint flexion angle of 90°), and to (ii) quantify the influence of tibia and femur length on 1MSTST performance. METHODS: Healthy participants were recruited for this randomised crossover study, performing each 1MSTST modality twice in a randomised order. The primary outcome was the number of repetitions in the 1MSTST. Secondary endpoints were the acute responses in peripheral oxygen saturation, heart rate, and leg fatigue and dyspnoea. Additionally, we investigated correlations of performance with knee extensor strength in both modalities. RESULTS: Thirty participants were recruited and completed the study. They achieved significantly less repetitions in the standardised 1MSTST compared to the individualised 1MSTST (B = - 12.1, 95% confidence interval [95% CI] = - 14.8/- 9.4, p < 0.001). We found a significant effect of femur length on 1MSTST performance (B = - 1.6, 95% CI = - 2.6/- 0.7, p = 0.01), tibia length showed significant interaction with the 1MSTST modality (B = 1.2, 95% CI = 0.2/2.2, p = 0.03). CONCLUSION: An individualisation of the 1MSTST starting position to 90° knee flexion angle leads to more repetitions compared to the traditional starting position. The higher repetition count is explained by controlling for differences in tibia length. We recommend individualisation of the 1MSTST, enabling more valid comparisons across populations and study samples. TRIAL REGISTRATION NUMBER: http://www. CLINICALTRIALS: gov , NCT04772417. TRIAL REGISTRATION DATE: February 26, 2021.

Concurrent and discriminant validity and reliability of an Android App to assess time, velocity and power during sit-to-stand test in community-dwelling older adults.

INTRODUCTION: Nowadays, smartphones are equipped with the most sophisticated hardware which provides the opportunity to develop specific smartphone apps to analyze kinetic and kinematic parameters during sit-to-stand test in a clinical setting. The aims were to ascertain whether a new Android video-analysis based-App is comparable to the previously validated Apple-App for measuring time, velocity and power during sit-to-stand test, to determine its reliability and discriminant validity. METHODS: One-hundred sixty-one older adults (61-86 years) were recruited from an elderly social center. Sit-to-stand variables were simultaneously recorded through the Android and Apple-App. Their validity and inter-rater, intra-rater, and test-retest reliability was tested using an intraclass correlation coefficient (ICC2-1). Low gait speed (< 1.0 m/s), low physical performance (Short Physical Performance Battery < 10 points), and sarcopenia (EWGSOP2 guideline) were used to determine discriminant validity which was reported as the area under the curves (AUC) and their effect sizes (Hedges' g) for independent sample t-test. RESULTS: Excellent reproducibility (ICC2-1 > 0.85) and strong agreement (ICC2-1 > 0.90) between operating systems for sit-to-stand variables derived from the App was found. Older adults classified as sarcopenic (11.2%), low physical performance (15.5%), or reduced gait speed (14.3%) showed worse sit-to-stand time, velocity and power with large effect sizes (Hedges' g: > 0.8) compared to their respective counterpart. These variables showed the acceptable-to-excellent ability to identify low gait speed, low physical performance, and sarcopenic older adults (AUC-range: 0.73-0.82). CONCLUSION: The new Sit-to-Stand App running on the Android operating system is comparable to the previously validated Apple App. Excellent reproducibility and acceptable-to-excellent discriminant validity were found.