Associations amongst dynamic knee stiffness during gait, quadriceps stiffness, and the incidence of knee osteoarthritis over 24 months: a cohort study with a mediation analysis.

BACKGROUND: Decreased strength and increased stiffness of the quadriceps have been associated with a higher risk of developing knee osteoarthritis (OA) in elders. Dynamic joint stiffness (DJS) represents collective resistance from active and passive knee structures for dynamic knee motions. Elevated sagittal knee DJS has been associated with worsening of cartilage loss in knee OA patients. Altered quadriceps properties may affect DJS, which could be a mediator for associations between quadriceps properties and knee OA. Hence, this study aimed to examine whether DJS and quadriceps properties would be associated with the development of clinical knee OA over 24 months, and to explore the mediation role of DJS in associations between quadriceps properties and knee OA. METHODS: This was a prospective cohort study with 162 healthy community-dwelling elders. Gait analysis was conducted to compute DJS during the loading response phase. Quadriceps strength and stiffness were evaluated using a Cybex dynamometer and shear-wave ultrasound elastography, respectively. Knee OA was defined based on clinical criteria 24 months later. Logistic regression with generalized estimating equations was used to examine the association between quadriceps properties and DJS and incident knee OA. Mediation analysis was performed to explore the mediation role of DJS in associations between quadriceps properties and the incidence of knee OA. RESULTS: A total of 125 participants (65.6 ± 4.0 years, 58.4% females) completed the 24-month follow-up, with 36 out of 250 knees identified as clinical knee OA. Higher DJS (OR = 1.86, 95%CI: 1.33-2.62), lower quadriceps strength (1.85, 1.05-3.23), and greater quadriceps stiffness (1.56, 1.10-2.21) were significantly associated with a higher risk of clinical knee OA. Mediation analysis showed that the DJS was not a significant mediator for the associations between quadriceps properties and knee OA. CONCLUSIONS: Higher sagittal knee dynamic joint stiffness, lower quadriceps strength, and greater quadriceps stiffness are potential risk factors for developing clinical knee OA in asymptomatic elders. Associations between quadriceps properties and knee OA may not be mediated by dynamic joint stiffness. Interventions for reducing increased passive properties of the quadriceps and knee joint stiffness may be beneficial for maintaining healthy knees in the aging population.

Reliability and validity of ultrasonography in evaluating the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals: a systematic review.

OBJECTIVE: To summarize the reliability and validity of ultrasonography in evaluating the stiffness, excursion, stiffness, or strain rate of diaphragm, intercostals and abdominal muscles in healthy or non-hospitalized individuals. LITERATURE SEARCH: PubMed, Embase, SPORTDiscus, CINAHL and Cochrane Library were searched from inception to May 30, 2022. STUDY SELECTION CRITERIA: Case-control, cross-sectional, and longitudinal studies were included if they investigated the reliability or validity of various ultrasonography technologies (e.g., brightness-mode, motion-mode, shear wave elastography) in measuring the thickness, excursion, stiffness, or strain rate of any respiratory muscles. DATA SYNTHESIS: Relevant data were summarized based on healthy and different patient populations. The methodological quality by different checklist depending on study design. The quality of evidence of each psychometric property was graded by the Grading of Recommendations, Assessment, Development and Evaluations, respectively. RESULTS: This review included 24 studies with 787 healthy or non-hospitalized individuals (e.g., lower back pain (LBP), adolescent idiopathic scoliosis (AIS), and chronic obstructive pulmonary disease (COPD)). Both inspiratory (diaphragm and intercostal muscles) and expiratory muscles (abdominal muscles) were investigated. Moderate-quality evidence supported sufficient (intra-class correlation coefficient > 0.7) within-day intra-rater reliability of B-mode ultrasonography in measuring right diaphragmatic thickness among people with LBP, sufficient between-day intra-rater reliability of M-mode ultrasonography in measuring right diaphragmatic excursion in non-hospitalized individuals. The quality of evidence for all other measurement properties in various populations was low or very low. High-quality evidence supported sufficient positive correlations between diaphragm excursion and forced expiratory volume in the first second or forced vital capacity (r > = 0.3) in healthy individuals. CONCLUSIONS: Despite the reported sufficient reliability and validity of using ultrasonography to assess the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals, further large-scale studies are warranted to improve the quality of evidence regarding using ultrasonography for these measurements in clinical practice. Researchers should establish their own reliability before using various types of ultrasonography to evaluate respiratory muscle functions. TRIAL REGISTRATION: PROSPERO NO. CRD42022322945.

Differential Effects of the COVID-19 Pandemic on Physical Activity Involvements and Exercise Habits in People With and Without Chronic Diseases: A Systematic Review and Meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis to summarize evidence regarding differential changes in physical activity (PA) involvements and exercise habits in people with and without chronic diseases during the COVID-19 outbreak. DATA SOURCES: MEDLINE, Embase, SPORTDiscus, Cumulative Index to Nursing and Allied Health, PsycINFO, Cochrane Library, and Physiotherapy Evidence Database were searched from November 2019 to May 2021. STUDY SELECTION: Two reviewers independently screened cross-sectional and longitudinal studies that investigated changes in PA-related outcomes in people with and without chronic diseases during the pandemic. DATA EXTRACTION: PA-related outcomes and sedentary time were extracted from the included studies. Relevant risk of bias were assessed. Meta-analyses were conducted for each PA-related outcome, if applicable. Quality of evidence of each PA-related outcome was evaluated by Grading of Recommendations Assessment, Development, and Evaluation. DATA SYNTHESIS: Of 1226 identified citations, 36 articles (28 with and 8 without chronic diseases) with 800,256 participants were included. Moderate evidence from wearable sensors supported a significant reduction in pooled estimates of step count (standardized mean differences [SMD]=-2.79, P<.01). Very limited to limited evidence substantiated significant decreases in self-reported PA-related outcomes and significant increases in sedentary behaviors among people with and without chronic diseases. Specifically, pooled estimates of metabolic equivalent-minute per week (SMD=-0.16, P=.02) and PA duration (SMD=-0.07, P<.01) were significantly decreased, while sedentary time (SMD=0.09, P=.04) showed significant increases in the general population (small to large effects). Very limited evidence suggested no significant PA changes among people in a country without lockdown. CONCLUSIONS: During the pandemic, objective and self-reported assessments showed significant reductions in PA in people with and without chronic diseases globally. This mainly occurred in countries with lockdowns. Although many countries have adopted the "live with the coronavirus" policy, authorities should implement population-based strategies to revert the potential lockdown-related long-term deleterious effects on people's health.

Real-Time Visual Biofeedback via Wearable Ultrasound Imaging Can Enhance the Muscle Contraction Training Outcome of Young Adults.

ABSTRACT: Huang, Z-H, Ma, CZ-H, Wang, L-K, Wang, X-Y, Fu, S-N, and Zheng, Y-P. Real-time visual biofeedback via wearable ultrasound imaging can enhance the muscle contraction training outcome of young adults. J Strength Cond Res 36(4): 941-947, 2022-Real-time ultrasound imaging (RUSI) can serve as visual biofeedback to train deep muscle contraction in clinical rehabilitative settings. However, its effectiveness in resistance training in sports/fitness fields remains unexplored. This article introduced a newly developed wearable RUSI system that provided visual biofeedback of muscle thickening and movement and reported its effectiveness in improving the training outcomes of muscle thickness change (%) during dynamic contraction. Twenty-five healthy young men participated and performed pec fly exercise both with and without RUSI biofeedback. Statistical analysis was conducted to examine the reliability of the measurements and the immediate effects of (a) RUSI biofeedback of muscle contraction and (b) training intensity (50 vs. 80% of 1-repetition maximum [1RM]) on the pectoralis major (PMaj) thickness change measured by ultrasound images. In addition to significantly high inter-contraction reliability (ICC3,1 > 0.97), we observed significantly increased PMaj thickness change for both training intensities upon receiving biofeedback in subjects, compared with without biofeedback (p < 0.001). We also observed significantly larger PMaj thickness change at 80% of 1RM compared with 50% of 1RM (p = 0.023). The provision of visual biofeedback using RUSI significantly enlarged the magnitude of PMaj thickness change during pec fly exercises, potentially indicating that RUSI biofeedback could improve the ability of targeted muscle contraction of PMaj in healthy young adults. To our knowledge, this study has pioneered in applying RUSI as a form of biofeedback during weight training and observed positive effectiveness. Future iterations of the technique will benefit more subject groups, such as athletes and patients with neuromuscular disorders.

Age-related increase in muscle stiffness is muscle length dependent and associated with muscle force in senior females.

BACKGROUND: In aging, muscle stiffness is considered as one of the factors associated with the reduction of force generation capability. There have been inconsistent findings on age-related alteration in the passive stiffness of quadriceps muscle in the female adults. Thus, the aim of this study was to determine the effect of aging on the shear moduli of the superficial muscle heads of the quadriceps and to explore its relationship with knee extension force. METHODS: Passive shear moduli of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) were measured at rest using shear wave elastography in 20 young and 20 senior female adults. Measurements were repeated at four knee joint positions, that is, 30°, 60°, 90°, and 105° of knee flexion. Maximal isometric voluntary knee extension force was assessed at 30°, 60°, and 90° of knee flexion. RESULTS: As per our findings, senior adults were determined to have significantly higher passive muscle shear moduli in the RF (by 34% - 68%; all p < 0.05) and the VL muscle heads (by 13%-16%, all p < 0.05) at and beyond 60° of knee flexion. Age-related increase in the VM was evident at 105° knee flexion (by11%, p = 0.020). The RF shear modulus was negatively correlated to the maximal isometric voluntary contraction force measured at 60° (r = - 0.485, p = 0.030) in senior adults. CONCLUSIONS: Senior female adults had greater passive stiffness at the superficial muscle heads of the quadriceps muscles when measured at long muscle length. Among the senior female adults, the passive stiffness of RF has been determined to have a negative association with the knee extensor force only at 60° knee flexion. No significant association was noted for other angles and muscles.

ICON PART-T 2019-International Scientific Tendinopathy Symposium Consensus: recommended standards for reporting participant characteristics in tendinopathy research (PART-T).

We aimed to establish consensus for reporting recommendations relating to participant characteristics in tendon research. A scoping literature review of tendinopathy studies (Achilles, patellar, hamstring, gluteal and elbow) was followed by an online survey and face-to-face consensus meeting with expert healthcare professionals (HCPs) at the International Scientific Tendon Symposium, Groningen 2018. We reviewed 263 papers to form statements for consensus and invited 30 HCPs from different disciplines and geographical locations; 28 completed the survey and 15 attended the meeting. There was consensus that the following data should be reported for cases and controls: sex, age, standing height, body mass, history of tendinopathy, whether imaging was used to confirm pathology, loading tests, pain location, symptom duration and severity, level of disability, comorbidities, physical activity level, recruitment source and strategies, and medication use history. Standardised reporting of participant characteristics aims to benefit patients and clinicians by guiding researchers in the conduct of their studies. We provide free resources to facilitate researchers adopting our recommendations.

ICON 2019-International Scientific Tendinopathy Symposium Consensus: There are nine core health-related domains for tendinopathy (CORE DOMAINS): Delphi study of healthcare professionals and patients.

BACKGROUND: The absence of any agreed-upon tendon health-related domains hampers advances in clinical tendinopathy research. This void means that researchers report a very wide range of outcome measures inconsistently. As a result, substantial synthesis/meta-analysis of tendon research findings is almost futile despite researchers publishing busily. We aimed to determine options for, and then define, core health-related domains for tendinopathy. METHODS: We conducted a Delphi study of healthcare professionals (HCP) and patients in a three-stage process. In stage 1, we extracted candidate domains from clinical trial reports and developed an online survey. Survey items took the form: 'The 'candidate domain' is important enough to be included as a core health-related domain of tendinopathy'; response options were: agree, disagree, or unsure. In stage 2, we administered the online survey and reported the findings. Stage 3 consisted of discussions of the findings of the survey at the ICON (International Scientific Tendinopathy Symposium Consensus) meeting. We set 70% participant agreement as the level required for a domain to be considered 'core'; similarly, 70% agreement was required for a domain to be relegated to 'not core' (see Results next). RESULTS: Twenty-eight HCP (92% of whom had >10 years of tendinopathy experience, 71% consulted >10 cases per month) and 32 patients completed the online survey. Fifteen HCP and two patients attended the consensus meeting. Of an original set of 24 candidate domains, the ICON group deemed nine domains to be core. These were: (1) patient rating of condition, (2) participation in life activities (day to day, work, sport), (3) pain on activity/loading, (4) function, (5) psychological factors, (6) physical function capacity, (7) disability, (8) quality of life and (9) pain over a specified time. Two of these (2, 6) were an amalgamation of five candidate domains. We agreed that seven other candidate domains were not core domains: range of motion, pain on clinician applied test, clinical examination, palpation, drop out, sensory modality pain and pain without other specification. We were undecided on the other five candidate domains of physical activity, structure, medication use, adverse effects and economic impact. CONCLUSION: Nine core domains for tendon research should guide reporting of outcomes in clinical trials. Further research should determine the best outcome measures for each specific tendinopathy (ie, core outcome sets).

Changes on Tendon Stiffness and Clinical Outcomes in Athletes Are Associated With Patellar Tendinopathy After Eccentric Exercise.

OBJECTIVE: Eccentric exercise is commonly used as a form of loading exercise for individuals with patellar tendinopathy. This study investigated the change of mechanical properties and clinical outcomes and their interrelationships after a 12-week single-legged decline-board exercise with and without extracorporeal shockwave therapy (ESWT). DESIGN: Randomized controlled trial. SETTING: Outpatient clinic of a university. PARTICIPANTS: Thirty-four male in-season athletes with patellar tendinopathy for more than 3 months were randomized into exercise and combined groups. INTERVENTIONS: The exercise group received a 12-week single-legged decline-squat exercise, and the combined group performed an identical exercise program in addition to a weekly session of ESWT in the initial 6 weeks. MAIN OUTCOME MEASURES: Tendon stiffness and strain were examined using ultrasonography and dynamometry. Visual analog scale and Victoria Institute of Sports Assessment-patella (VISA-p) score were used to assess pain and dysfunction. These parameters were measured at preintervention and postintervention. RESULTS: Significant time effect but no significant group effect on the outcome measures; significant reduction in tendon stiffness (P = 0.02) and increase in tendon strain (P = 0.00); and reduction of intensity of pain (P = 0.00) and dysfunction (P = 0.00) were observed. Significant correlations between changes in tendon stiffness and VISA-p score (ρ = -0.58, P = 0.05); alteration in tendon strain, pain intensity (ρ = -0.63, P = 0.03); and VISA-p score (ρ = 0.60, P = 0.04) were detected after the exercise program. CONCLUSIONS: Eccentric exercise-induced modulation on tendon mechanical properties and clinical symptoms are associated in athletes with patellar tendinopathy.

One Session of Extracorporeal Shockwave Therapy-Induced Modulation on Tendon Shear Modulus is Associated with Reduction in Pain.

The aim of the study was to examine the immediate effect of 1 session of extracorporeal shockwave therapy (ESWT) on patellar tendon stiffness and to explore the relationship between the change in tendon stiffness and the pain intensity. Thirty-four male athletes aged 22.2 ± 3.8 with patellar tendinopathy were recruited. The participants were randomized into ESWT and sham groups. The ESWT group received 1500 impulses of ESWT at 4 Hz with maximal tolerable pain intensity and the sham group received intensities below 0.08 mJ/mm2. Supersonic Shearwave Imaging (SSI) was used to measure tendon shear modulus (an index of tissue stiffness), and a visual analogue scale was used to quantify the pain intensity during compression with 10 lb (4.535 kg) pressure directed on the most tender part and then during a single-leg declined-squat test. A significant reduction in tendon shear modulus (from 57.4 ± 25.5 kPa to 40.6 ± 17.6kPa, p = 0.001) was detected in the ESWT receiving ESWT with an intensity from 0.13-0.33 mJ/mm2 but not the sham group (from 47.7 ± 17.1 kPa to 41.0 ± 12.7 kPa; p = 0.06). In the ESWT group, the change in tendon shear modulus was associated with the change in the intensity of pain during single-legged declined-squat test (ρ = 0.55; p = 0.023) but not pressure pain (p > 0.05). These findings suggest that one session of ESWT induces reduction of tendon stiffness in volleyball and basketball players with patellar tendinopathy. The reduction in tendon stiffness is associated with reduction in pain during single-legged declined-squat test.

The Effects of Rigid Scapular Taping on the Subacromial Space in Athletes With and Without Rotator Cuff Tendinopathy: A Randomized Controlled Study.

CONTEXT: Reduction of the subacromial space (SAS) during arm elevation may contribute to rotator cuff (RC) tendinopathy. The effects of scapular taping on the SAS in athletes with and without RC tendinopathy are unknown. OBJECTIVE: To investigate the immediate effects of scapular taping on the SAS in athletes with and without RC tendinopathy. DESIGN: Randomized controlled study with repeated measures. SETTING: University laboratory. PARTICIPANTS: A total of 43 male volleyball players (17 asymptomatic and 26 with RC tendinopathy, mean age = 22.9 [3.5] y) participated in the study. INTERVENTION: Three scapular taping protocols-no taping (control), taping with tension (therapeutic taping), and taping without tension (sham taping). MAIN OUTCOME MEASURES: Ultrasound measurements of the SAS with the arm at 0° and 60° of shoulder abduction, and the change in the SAS between 0° and 60° of shoulder abduction (SAS0°-60°) were calculated. RESULTS: Athletes with RC tendinopathy demonstrated larger SAS with therapeutic taping at 60° of shoulder abduction (6.9 [1.9] mm vs 5.8 [1.7] mm, mean difference = 1.1 mm, 95% confidence interval, -1.80 to -0.39, P = .002) when compared with the no taping condition. The tendinopathy group also showed less reduction in the SAS with therapeutic taping during SAS0°-60° (2.0 [1.4] mm vs 2.8 [1.4] mm, P = .02) when compared with the no taping condition. When tape was applied to the scapula in asymptomatic athletes, our results showed a relatively small increase in the SAS with therapeutic taping during arm resting at 0° of abduction when compared with the no taping condition (8.7 [0.9] mm vs 8.3 [0.8] mm, mean difference = 0.4 mm, 95% confidence interval, -0.71 to -0.11, P = .01). CONCLUSIONS: Athletes with RC tendinopathy demonstrated less reduction of the SAS with rigid scapular taping during early arm abduction. Such observation was not evidenced in asymptomatic athletes.

Alterations in mechanical properties of the patellar tendon is associated with pain in athletes with patellar tendinopathy.

PURPOSE: To compare tendon strain and stiffness between athletes with patellar tendinopathy and healthy controls, and explore whether the intensity of pain and dysfunction were related to the mechanical properties of the tendon. METHODS: Thirty-four male athletes with patellar tendinopathy and 13 healthy controls matched by age and activity levels were recruited. The in vivo mechanical properties of the patellar tendon were examined by ultrasonography and dynamometry. In subjects with patellar tendinopathy, the intensities of self-perceived pain (maximal pain in the past 7 days and pain during a single-legged declined-squat test) using the visual analogue scale and the assessment of functional disability using the Victorian Institute of Sport Assessment-patellar questionnaire, were collected. RESULTS: In subjects with patellar tendinopathy, tendon strain was significantly reduced by 22% (8.9 ± 3.7 vs. 14.3 ± 4.7%, P = 0.005) when compared with healthy controls. There was no significant group difference in tendon stiffness (P = 0.27). Significant negative correlations between tendon strain and the maximal self-perceived pain over 7 days (r = -0.37, P = 0.03), and pain during a single-legged declined-squat test (r = -0.37, P = 0.03) were detected. A trend of significant positive correlation was found between tendon stiffness and pain during a single-legged declined-squat test (r = 0.30, P = 0.09). CONCLUSION: Our findings show that tendon strain is reduced in athletes with patellar tendinopathy, and a lower tendon strain is associated with a greater magnitude of pain perceived.

Tendon vascularity in overhead athletes with subacromial pain syndrome and its correlation with the resting subacromial space.

BACKGROUND: Supraspinatus tendinopathy is one of the common causes of subacromial pain syndrome (SAPS) in overhead athletes. Changes in tendon vascularity have been reported in painful tendons; however, the prevalence and distribution have not been investigated in young overhead athletes. METHODS: We conducted a cross-sectional study of 47 overhead athletes (male, 31; female, 16) aged 18 to 36 years with SAPS for >3 months. A sonographer graded the severity of the tendinopathy and area of vascularization. Ultrasound imaging was used to measure supraspinatus tendon thickness, vascularity, and resting subacromial space. A self-written program was used to semiquantify the intensity of vascularity, expressed as the vascular index. RESULTS: The majority (87.2%) of the participants had signs of tendinopathy in the supraspinatus tendon, and 40 (85.1%) of the tendinopathic tendons had vascularity. The majority (66.0%) of the vascularized subjects presented with minimal increase in vascularity, and 19.1% had moderate to severe vascularization. Most (79.2%) of the vascularization was observed in the pericortical region. The vascular index was negatively correlated with the resting subacromial space in male athletes with a reduced subacromial space (ρ = -0.63; P = .038). CONCLUSION: Of overhead athletes with SAPS, 87.2% had supraspinatus tendinopathy with minimal to moderate vascularization, with the majority of vascularization occurring in the pericortical region. In male athletes with a reduced subacromial space, greater vascularity in the supraspinatus tendon was associated with a smaller resting subacromial space.

Out-of-Hospital Cardiac Arrest Before and During the COVID-19 Pandemic in Hong Kong: Registry-Based Study From 2017 to 2023.

BACKGROUND: The COVID-19 pandemic has exerted a significant toll on individual health and the efficacy of health care systems. However, the influence of COVID-19 on the frequency and outcomes of out-of-hospital cardiac arrest (OHCA) within the Chinese population, both before and throughout the entire pandemic period, remains to be clarified. OBJECTIVE: This study aimed to fill the gaps by investigating the prevalence and outcomes of OHCA in Hong Kong (HK) both before and during the whole pandemic period. METHODS: This is a retrospective regional registry study. The researchers matched OHCA data with COVID-19-confirmed case records between December 2017 and May 2023. The data included information on response times, location of OHCA, witness presence, initial rhythm, bystander cardiopulmonary resuscitation (CPR), use of public-access defibrillation, resuscitation in the accident and emergency department, and survival to admission. Descriptive analyses were conducted, and statistical tests such as analysis of variance and χ2 were used to examine differences between variables. The incidence of OHCA and survival rates were calculated, and logistic regression analysis was performed to assess associations. The prevalence of OHCA and COVID-19 during the peak of the pandemic was also described. RESULTS: A total of 43,882 cases of OHCA were reported in HK and included in our analysis. Around 13,946 cases were recorded during the prepandemic period (2017-2019), and the remaining 29,936 cases were reported during the pandemic period (2020-2023). During the pandemic period, the proportion of female patients increased to 44.1% (13,215/29,936), and the average age increased slightly to 76.5 (SD 18.5) years. The majority of OHCAs (n=18,143, 61.1% cases) occurred at home. A witness was present in 45.9% (n=10,723) of the cases, and bystander CPR was initiated in 44.6% (n=13,318) of the cases. There was a significant increase in OHCA incidence, with a corresponding decrease in survival rates compared to the prepandemic period. The location of OHCA shifted, with a decrease in incidents in public places and a potential increase in incidents at home. We found that CPR (odds ratio 1.48, 95% CI 1.17-1.86) and public-access defibrillation (odds ratio 1.16, 95% CI 1.05-1.28) were significantly associated with a high survival to admission rate during the pandemic period. There was a correlation between the development of OHCA and the prevalence of COVID-19 in HK. CONCLUSIONS: The COVID-19 pandemic has had a significant impact on OHCA in HK, resulting in increased incidence and decreased survival rates. The findings highlight the importance of addressing the indirect effects of the pandemic, such as increased stress levels and strain on health care systems, on OHCA outcomes. Strategies should be developed to improve OHCA prevention, emergency response systems, and health care services during public health emergencies to mitigate the impact on population health.

Reliability of Ultrasound Shear Wave Elastography for Evaluating Psoas Major and Quadratus Lumborum Stiffness: Gender and Physical Activity Effects.

OBJECTIVE: We aimed to assess the reliability of quantifying psoas major (PM) and quadratus lumborum (QL) stiffness with ultrasound shear wave elastography (SWE), and to explore the effects of gender and physical activity on muscle stiffness. METHODS: Fifty-two healthy participants (18-32 y) were recruited. To determine reliability, 29 of them underwent repeated SWE measurements of PM and QL stiffness by an operator on the same day. The intra-class correlation coefficients (ICC3,1), standard error of measurement (SEM) and minimal detectable change with 95% confidence interval (MDC95) were calculated. The rest participants underwent a single measurement. Two-way MANCOVA was conducted for the effects of gender and physical activity on muscle stiffness. RESULTS: The observed reliability for PM (ICC3,1 = 0.89-0.92) and QL (ICC3,1 = 0.79-0.82) were good-to-excellent and good, respectively. The SEM (kPa) was 0.79-1.03 and 1.23-1.28, and the MDC95 (kPa) was 2.20-2.85 and 3.41-3.56 for PM and QL, respectively. After BMI adjustment, both gender (PM: F = 10.15, p = 0.003; QL: F = 18.07, p < 0.001) and activity level (PM: F = 5.90, p = 0.005; QL: F = 6.33, p = 0.004) influenced muscle stiffness. The female and inactive groups exhibited higher stiffness in both muscles. CONCLUSION: SWE is reliable for quantifying the stiffness of PM and QL. Female and physical inactivity may elevate PM and QL stiffness, underscoring the importance of accounting for these factors in muscle stiffness investigations. Larger prospective studies are needed to further elucidate their effects.

Associations between paraspinal muscle characteristics and spinal curvature in conservatively treated adolescent idiopathic scoliosis: a systematic review.

BACKGROUND CONTEXT: Children with adolescent idiopathic scoliosis (AIS) may show asymmetrical paraspinal muscle characteristics. PURPOSE: To summarize the evidence regarding: (1) the associations between various paraspinal muscle characteristics and spinal curvature; (2) whether paraspinal muscle properties significantly differed between children with and without AIS; and (3) whether baseline paraspinal muscle characteristics predicted curve progression. STUDY DESIGN/SETTING: Systematic literature review. METHODS: Five databases (CINAHL, Academic Search Premier, MEDLINE, Scopus, and PubMed) were searched from inception to May 2022. This protocol was registered in the PROSPERO database of systematic reviews CRD 42020171263. The Critical appraisal skills program, the Appraisal Tool for Cross-Sectional Studies and Quality In Prognosis Studies tool were used to evaluate the risk of bias of the included studies. The strength of evidence of each identified association was determined by the Grading of Recommendations Assessment, Development, and Evaluation System (GRADE). RESULTS: Of 1,530 identified citations, four cohort, 17 cross-sectional, and 23 case-control studies including 31 with low, nine with moderate and four with high risk of bias were included. Low to very low-strength evidence supported that the convex side of the curve had more type I muscle fibers, higher muscle volume and paraspinal muscle activity, while the concavity had more intramuscular fatty infiltration. Very low-strength evidence substantiated greater side-to-side surface electromyography signals during left trunk bending in prone lying, standing, and standing with perturbation between people with and without AIS. Also, low to very low-strength evidence supported that a larger side-to-side surface electromyography ratio at the lower end vertebra predicted curve progression. CONCLUSIONS: Our review highlights that paraspinal muscles on the concavity of the curve demonstrate consistent changes (ie, altered muscle-related gene expression, muscle atrophy, increased fatty infiltration, reduced type I fibers, and reduced muscle activity), which may be the cause or consequence.

Comparative effectiveness of non-pharmacological interventions on sleep in individuals with chronic musculoskeletal pain: A systematic review with network meta-analysis.

This network meta-analysis aimed to estimate the comparative effectiveness of non-pharmacological interventions on sleep in individuals with chronic musculoskeletal pain. Seven databases were systematically searched up to February 2023. A random-effects network meta-analysis in a frequentist framework was performed to synthesize continuous data as standardized mean differences (SMD) along with a 95% confidence interval (95% CI). A total of 15,641 records were identified, and 107 randomized controlled trials involving 8,121 participants were included. Of 14 identified interventions, eight were significantly more effective than passive control in improving sleep quality at immediate post-intervention (SMDs = 0.67-0.74), with cognitive behavioral therapy (CBT) being the most effective treatment (SMD = 0.74, 95% CI: 0.45-1.03). Only CBT demonstrated sustained effects at short-term (SMD = 1.56; 95% CI: 0.62-2.49) and mid-term (SMD = 1.23; 95% CI: 0.44-2.03) follow-ups. Furthermore, CBT significantly improved subjective (SMD = 0.64; 95% CI: 0.25-1.03) and objective (SMD = 0.30; 95% CI: 0.01-0.59) sleep efficiency compared with passive control at immediate post-intervention. Our findings support CBT as the first-line treatment for improving sleep in individuals with chronic musculoskeletal pain, given its superior effectiveness across multiple sleep outcomes and its sustainable effects until mid-term follow-up. However, the certainty of evidence for these interventions in improving sleep quality was very low to low.

Histological, Physiological and Biomechanical Effects of Low-Level Laser Therapy on Tendon Healing in Animals and Humans: A Systematic Review.

Low-level Laser Therapy (LLLT) was widely used in clinical practice for tendon disorders. However, the underlying mechanisms and effectiveness of LLLT in treating tendon injury remain unclear. Therefore, the present study was conducted aiming to summarize the evidence regarding the histological, physiological, and biomechanical effects of LLLT on tendon healing in animal and human models. Four databases were searched for relevant literature. Four independent reviewers screened abstracts and full-text articles, extracted relevant data, evaluated the risk of bias, and quantified the quality of evidence. Database searches yielded 1400 non-duplicated citations. Fifty-five studies were included (50 animal and five human studies). Animal studies revealed that LT had stimulating effects on collagen organization, collagen I and collagen II formation, matrix metalloproteinase (MMP)-8, transforming growth factor ß1, vascular endothelial growth factor, hydroxyproline, maximum load, maximum elongation before breaking, and tendon stiffness. However, LLLT had inhibitory effects on the number of inflammatory cells, histological scores, relative amount of collagen III, cyclooxygenase-2, prostaglandin E2 (PGE2), interleukin-6, tumor necrosis factor-α, MMP-1, and MMP-3. Although one human study found that LLLT reduced the concentration of PGE2 in peritendinous tissue of the Achilles tendon, other human studies revealed that the effects of LLLT on the physiology and biomechanics of human tendons remained uncertain. LLLT facilitates tendon healing through various histological, physiological, and biomechanical effects in animal models. Only post-LLLT anti-inflammatory effects were found in human studies.

Strength and passive stiffness of the quadriceps are associated with patellar alignment in older adults with knee pain.

BACKGROUND: Maintaining normal patellar alignment is important for knee health. Altered activation of individual quadriceps muscles have been found related to patellar alignment. However, the relationships between strength and passive stiffness of the quadriceps and patellar alignment remains unexplored. METHODS: Participants aged between 60 and 80 years with activity-induced knee pain were recruited. Knee pain was quantified using an 11-point numeric rating scale. Quadriceps strength was assessed using a Cybex dynamometer and passive stiffness of rectus femoris, vastus lateralis, and vastus medialis were measured by shear-wave ultrasound elastography. Patellar alignments were assessed using MR imaging. Linear regression was used to examine relationships between quadriceps properties and patellar alignments with and without controlling for potential covariates. FINDINGS: Ninety-two eligible participants were assessed (71.7% females, age: 65.6 ± 3.8 years; pain scale: 4.6 ± 2.0), most of whom had knee pain during stair climbing (85.9%). We found that 17% of patellar lateral tilt angle could be explained by lower quadriceps strength (adjusted R2 = 0.117; P < 0.001), especially in females (R2 = 0.281; P < 0.001; adjusted R2 = 0.211; P < 0.001). In addition, a higher stiffness ratio of vastus lateralis/medialis accounted for 12% of patellar lateral displacement (adjusted R2 = 0.112; P = 0.008). INTERPRETATION: Quadriceps strength and relative stiffness of lateral to medial heads are associated with patellar alignment in older adults with knee pain. It suggests that quadriceps weakness and relatively stiffer lateral quadriceps may be risk factors related to patellar malalignments in the elderly.

Goal-setting and personalization under the International Classification of Functioning, Disability, and Health framework: Community reintegration program for post-stroke patients.

Background: Body functions and structures, activities, and participation are the core components in the International Classification of Functioning, Disability, and Health (ICF) to identify post-stroke patients' health conditions. The specification of health conditions enhances the outcomes of post-stroke rehabilitation. Purpose: This study aimed to explore the extent and the processes in an ICF-based post-stroke rehabilitation program (ICF-PSRP) that could enhance patients' community reintegration level. Methods: Post-stroke patients who completed the ICF-PSRP participated in intake and pre-discharge individual face-to-face semi-structured interviews. In addition, case therapists were invited to a face-to-face semi-structured group interview. Clinician experts were invited to complete an interview with the same interview contents as case therapists but in an online format. All interview recordings were analyzed with the Framework analysis. Patients' treatment goals were mapped with the ICF Core Set for Stroke. Results: Out of 37 invited post-stroke patients, thirty-three of them completed the interview. Three case therapists and five clinicians completed the interviews. The goals set by the patients and their caregivers showed a broadening of their scope over the course of the program. The changes in scope ranged from the activities to the participation and environmental components. Increases in patient-therapist interactions played an essential role in the goal-setting process, which were integral to personalizing the treatment content. These characteristics were perceived by all parties who contributed to the program outcomes. Conclusion: The application of ICF's principles and core components offers a useful framework for enhancing post-stroke patients' community reintegration level. Future studies should explore the way in which patient-therapist interaction, exposure to environmental factors, and personalized interventions maximize the benefits of applying this framework to the community integration of post-stroke patients.