Outcome measures in pediatric chronic inflammatory demyelinating polyradiculoneuropathy.

INTRODUCTION/AIMS: Objective outcome measures in children undergoing treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are lacking. The aim of the study was to record serial grip strength and motor nerve conduction studies to assess interval change. METHODS: This was a retrospective review of 16 children (8 females and 8 males; median age, 9.7 years; interquartile range, 6-13 years) with CIDP followed at a tertiary children's hospital from 2013 to 2021. Subjects were treated with intravenous immunoglobulin (IVIG). Right and left grip strength measurements were obtained at each clinic visit using a handheld dynamometer. Annual right median motor nerve conduction study data were recorded during the study period. RESULTS: Mean duration of follow-up was 2.9 years. Grip strength (right: 0.19 kg/month, p < 0.001; left 0.23 kg/month, p < 0.001) and median F-wave latencies (-0.23/month, p = 0.015) showed significant improvement over time. Akaike information criterion showed time + IVIG frequency <21 days as best fit for grip strength and distal compound muscle action potential amplitude. DISCUSSION: Our study results indicate serial grip strength measurements are a feasible and objective way to assess motor strength improvement in children with CIDP receiving immunotherapy.

Reliability of a new stabilization device for measurement of muscle strength using a hand-held dynamometer.

INTRODUCTION/AIMS: The hand-held dynamometer (HHD) is a reliable and portable tool for quantitatively assessing muscle strength. However, a number of variables, including the strength of the tester, the adequacy of stabilization, and the selected testing position, can affect the reliability of the device. The objective of the present study was to examine the reproducibility and inter-rater reliability of strength assessments using HHD with and without a stabilization device. METHODS: Strength assessments were conducted with and without the stabilization device by two independent raters. Healthy volunteers with no history of musculoskeletal disorders were included in the study. The strength of the shoulder flexion, scapula elevation, knee extension, and hip abduction muscle groups was evaluated using HHD. The reliability of the measurements was evaluated using intra-class correlation (ICC), standard error of measurement, and minimal detectable change. RESULTS: Fifty-two healthy volunteers (age 21.51 ± 2.02 years) participated in the study. The reproducibility was found to be excellent (ICC = 0.89-0.99). While reliability between the assessors was good to excellent (ICC = 0.85-0.93), reliability between assessors and device was found moderate to good (ICC = 0.48-0.78). DISCUSSION: The strength values obtained for all directions of movement with the stabilization device were found to be significantly higher than those obtained without fixation of the HHD. It can be concluded that the data obtained from the assessors and HHD with stabilization device are not comparable. Moreover, the utilization of a stabilization device may serve to enhance the reliability of the measurements by eliminating the rater effect.

Effects of photobiomodulation on pain, lactate and muscle performance (ROM, torque, and EMG parameters) of paretic upper limb in patients with post-stroke spastic hemiparesis-a randomized controlled clinical trial.

The objective of the study was to investigate the impact of photobiomodulation (PBM) on the paretic upper limb in post-stroke patients with spastic hemiparesis and to understand the potential of PBM as a long-term non-invasive therapy for reducing the side effects caused by spasticity in the hemiparetic upper limb after a stroke. This is a double-blind randomized clinical trial constituted of 27 participants, being Control group (CG = 12 healthy individuals) and PBM group (PBMG = 15 post-stroke individuals). In the CG, the baseline blood lactate (BL) was evaluated, followed by the evaluation of the IC torque of the biceps and triceps muscles, with the isokinetic dynamometer associated with surface electromyography (EMG) and, subsequently, a new measurement of BL. The PBMG received 10 sessions of treatment with PBM (780 nm, Power: 100 mV, Power Density: 3.18 W/cm2, Energy: 4 J, Fluency: 127.4 J/cm2, Time: 40 s per point and 1.280 s total, Spot: 0.0314 cm2, 32 Points: 16 points (brachial biceps) and 16 points (brachial triceps) applied with contact at 90°, Total Energy: 64 J), which in the pre-treatment evaluation measured BL, the visual analogue scale (VAS) of pain; torque and EMG of the same muscles in the IC, subsequently, a new measurement of VAS and BL, and measurement of range of motion (ROM) during the reaching movement. At the conclusion of the ten sessions, all participants underwent a reassessment, wherein all tests originally administered during the initial evaluation were repeated. Subsequently, the data were analyzed using the Shapiro-Wilk normality test. For related data, the paired t-test was used for normal distributions and the Wilcoxon test for non-normal data. For unrelated data, the t test was used for normal distributions and the Mann-Whitney test for non-normal data. Muscle torque was higher for the CG, with a significant difference (CGxPBMG = p < 0.0001). There was no significant difference between the EMG values of the CG in relation to the Pre-PBM phase and with the Post-PBM phase of the PBMG (p > 0.05). On the other hand, there was a 38% reduction in pain reported by hemiparetic patients (p = 0.0127) and a decrease in BL in the PBMG. Post-PBM ROM increased by 46.1% in the elbow extension of the paretic limb. In conclusion, Photobiomodulation (PBM) demonstrated significant improvements in muscle performance, reducing fatigue and pain levels, and enhancing range of motion in post-stroke patients with spastic hemiparesis. These findings support the potential integration of PBM into rehabilitation protocols, but further research and clinical trials are needed to validate and expand upon these promising outcomes.

Minimum effective plyometric training volume in sedentary individuals: Impact on lower limb viscoelastic properties and functional performance in a randomised controlled trial.

Sedentary lifestyles reduce muscle mass, strength, power, and alter viscoelastic properties. Plyometric jump training (PJT) shows promise in countering these effects, but the optimal training volume for individuals with low athletic performance remains unclear. This study aimed to determine the minimal PJT volume required to improve muscle and tendon viscoelastic properties, strength, and power in sedentary individuals. A double-blind randomised controlled trial included 44 participants divided into three groups: Control Group (CG) (n = 16), Reduced Volume Training Group (RVTG) (n = 16), and Training Group (TG) (n = 12). The four-week PJT programme involved three weekly sessions with gradual volume increments; RVTG performed 50% less volume than TG. Baseline and follow-up assessments included the isokinetic standing up (SU) and sitting down (SD) phases at 15 cm/s and 5 cm/s, and myotonometer measurements. In the SU phase at 15 cm/s, significant differences were found (p = 0.01) with higher values in TG (10.0 ± 3.3 N/kg) compared to CG and RVTG. At 5 cm/s, differences in SD were observed (p = 0.002). For Achilles tendon properties in RVTG: stiffness (p = 0.04), decrement (p = 0.01), and relaxation (p = 0.02). A PJT volume of 2,414 jumps improved muscle strength, while 1,207 jumps altered tendon properties.

Low-Cost Dynamometer for Measuring and Regulating Wrist Extension and Flexion Motor Tasks in Electroencephalography Experiments.

A brain-computer interface could control a bionic hand by interpreting electroencephalographic (EEG) signals associated with wrist extension (WE) and wrist flexion (WF) movements. Misinterpretations of the EEG may stem from variations in the force, speed and range of these movements. To address this, we designed, constructed and tested a novel dynamometer, the IsoReg, which regulates WE and WF movements during EEG recording experiments. The IsoReg restricts hand movements to isometric WE and WF, controlling their speed and range of motion. It measures movement force using a dual-load cell system that calculates the percentage of maximum voluntary contraction and displays it to help users control movement force. Linearity and measurement accuracy were tested, and the IsoReg's performance was evaluated under typical EEG experimental conditions with 14 participants. The IsoReg demonstrated consistent linearity between applied and measured forces across the required force range, with a mean accuracy of 97% across all participants. The visual force gauge provided normalised force measurements with a mean accuracy exceeding 98.66% across all participants. All participants successfully controlled the motor tasks at the correct relative forces (with a mean accuracy of 89.90%) using the IsoReg, eliminating the impact of inherent force differences between typical WE and WF movements on the EEG analysis. The IsoReg offers a low-cost method for measuring and regulating movements in future neuromuscular studies, potentially leading to improved neural signal interpretation.

Variability between Different Hand-Held Dynamometers for Measuring Muscle Strength.

Muscle strength is routinely measured in patients with neuromuscular disorders by hand-held dynamometry incorporating a wireless load cell to evaluate disease severity and therapeutic efficacy, with magnitude of effect often based on normative reference values. While several hand-held dynamometers exist, their interchangeability is unknown which limits the utility of normative data. We investigated the variability between six commercially available dynamometers for measuring the isometric muscle strength of four muscle groups in thirty healthy individuals. Following electro-mechanical sensor calibration against knowns loads, Citec, Nicholas, MicroFET2, and Commander dynamometers were used to assess the strength of ankle dorsiflexors, hip internal rotators, and shoulder external rotators. Citec, Jamar Plus, and Baseline Hydraulic dynamometers were used to capture hand grip strength. Variability between dynamometers was represented as percent differences and statistical significance was calculated with one-way repeated measures ANOVA. Percent differences between dynamometers ranged from 0.2% to 16%. No significant differences were recorded between the Citec, Nicholas, and MicroFET2 dynamometers (p > 0.05). Citec grip strength measures differed to the Jamar Plus and Baseline Hydraulic dynamometers (p < 0.01). However, when controlling for grip circumference, they were comparable (p > 0.05). Several hand-held dynamometers can be used interchangeably to measure upper and lower limb strength, thereby maximising the use of normative reference values.

Association Between Typologies of Sedentary Behavior and Muscle Strength, Gait Speed, and Balance in Community-Dwelling Older Adults.

Knowledge of how the different types of sedentary behaviors (SB) are associated with functional limitations can guide professionals who work with older adults on better recommendations about the amount of daily time that should be encouraged in each type of SB. The objective was to estimate the associations between two SB typologies (SB television [TV] and SB computer/internet) and the presence of handgrip strength, lower limb strength, gait speed, and balance limitations in Brazilian community-dwelling older adults. This is a cross-sectional study with 1,298 community-dwelling older adults (≥60 years). SB was assessed by self-reporting daily time spent watching TV or using computer/internet (categorized into <2, 3-4, and ≥5 hr/day). Outcomes were handgrip strength, lower limb strength, gait speed, and balance limitations considering referenced cutoff points. Older adults in SB TV ≥5 hr/day had 1.75 (95% confidence interval [CI] [1.07, 2.86]) and 1.88 (95% CI [1.02, 3.46]) times more chances of handgrip strength and gait speed limitations, respectively. On the other hand, those who spent 3-4 and ≥5 hr/day in SB computer/internet had 0.45 (95% CI [0.20, 0.99]) and 0.37 (95% CI [0.15, 0.93]) had less chances of lower limb strength and balance limitations, respectively. In conclusion, functional limitations would be associated differently depending on the type of SB in the older adults sampled.

Handgrip strength and upper limb functional performance measures in people over 18 years old: Analysis of relationships and influencing factors.

BACKGROUND: Handgrip strength is a common, simple, and inexpensive method to measure muscle strength. On the other hand, the functional performance measurement involves a usual task which implies repeating elements between the individuals' interaction and the environment. This is fundamental for projecting their results to daily life situation. PURPOSE: To explore the relationship between grip strength and measures of functional performance of the upper limbs (ULs) in people over 18 years of age, and to determine the influence of sociodemographic and anthropometric variables on the relationship. STUDY DESIGN: A cross-sectional study was conducted under the analytical empirical approach, using linear associations between handgrip strength and functional performance measurement tests (correspondence analysis). METHODS: Three hundred sixty-two male and female individuals between 18 and 91 years of age from 4 Colombian cities participated. The grip strength of both ULs measured with a digital dynamometry was associated with the Box and Block Test (BBT, manual dexterity), Nine-Hole Peg Test (NHPT, daily living tasks), and Jebsen-Taylor Hand Function Test (JJT, ability to grasp, pick up, and place). Multiple linear regression analyzes were performed to assess possible explanatory factors of a sociodemographic and anthropometric order. RESULTS: A significant association was found between the grip strength of dominant and non-dominant ULs with all functional performance tests (ρ > 0.27 and p < .001), except for the writing and simulated feeding subtests of the JJT (ρ ≤ 0.16). An interactive effect of age was found in the relationship between grip strength and the 3 functional performance tests. CONCLUSIONS: These results support the association between grip strength with the NHPT, JJT, and BBT measures and the interactive effect of age on the performance of all tests.

Effect of Kinesio taping on wrist proprioception in healthy subjects: A randomized clinical trial.

BACKGROUND: Although the use of KT has increased considerably in the clinical practice in the last years, there is limited evidence about the effects of its application in proprioception. PURPOSE: The aim of this study was to determine the effect of KT on joint position sense and force sense on the wrist of healthy subjects. METHODS: Fifty-four subjects were analyzed in a randomized, crossover, single-blind study design. To determine the force sense, the subjects had to reach 50% of their maximum grip force. Wrist joint position sense was assessed during active repositioning tests at the target angles of 30° flexion and extension of wrist. A digital dynamometer was used to determine the sense of force and a digital goniometer was used to determine the joint position sense. Subjects were evaluated with KT (I- strip on ventral aspect of forearms from origin to insertion) and placebo (an inelastic tape was applied following the same procedure as KT). RESULTS: No significant differences have been found in the force sense, neither in the comparisons between control and interventions (p=0.286), nor between pre and post-intervention (p=0.111). For wrist joint position sense, a statistically significant effect (p< 0.05) was found at 30º of extension between the control and experimental group in favor of the control group. CONCLUSIONS: The application of KT did not produce changes in FS and only caused a significant improvement in JPS in extension (30º). The results appear to indicate that the application of KT to improve proprioception in healthy subjects should be reconsidered.

Assessment of Isokinetic Trunk Muscle Strength and Fatigue Rate in Individuals after Bariatric Surgery.

Background and Objectives: Lean body mass loss after bariatric surgery (BS) is remarkable, despite an effective long-term mass reduction and significant declines in comorbidities. A person's functional capacity is adversely affected when their skeletal muscle strength declines by up to 30%. This study aimed to assess the isokinetic trunk muscle strength and fatigue rate in individuals after BS. Materials and Methods: This study included fifty-eight patients, both male and female, ranging in age from 19 to 45. Twenty-seven individuals had BS and twenty-seven healthy people served as the control group. The primary outcomes were the measurement of the concentric and eccentric isokinetic muscle strength of the trunk flexor and extensor muscles. An isokinetic dynamometer (Biodex Rehabilitation and Testing System 3) was used for the assessment of the isokinetic muscle strength. Noraxon EMG was used to determine a secondary outcome, which was the median frequency slop (MF/time) and root mean square slop (RMS/time) of the lumbar erector spinea muscle at 50% of the Maximum Voluntary Isometric Contraction (MVIC). Outcome measures were assessed for both groups. Results: Compared to the control group, the bariatric group showed a lower mean value of both concentric and eccentric isokinetic muscle strength for the flexor and extensor trunk muscles (p < 0.05). In terms of the EMG fatigue rate, the RMS slope increased significantly more than that of the control group, while the MF slope decreased (p > 0.05). Conclusions: The current study found that, in comparison to the healthy subjects, the BS group showed reduced levels of fatigue and isokinetic strength in the trunk muscles. Based on these results, it is recommended that individuals who underwent BS take part in tailored rehabilitation programs to avoid potential musculoskeletal issues in the future.

Validity and Reliability of Handheld Dynamometry to Assess Isometric Hamstrings and Quadriceps Strength at Varying Muscle Lengths.

CONTEXT: The hamstrings are the most commonly injured muscle in sports and are especially injury prone in lengthened positions. Measuring knee muscle strength in such positions could be relevant to establish injury risk. Handheld dynamometry has been shown to be a valid, reliable, and practical tool to measure isometric muscle strength clinically. The aim of this study was to assess the validity and reliability of the assessment of isometric knee muscle strength with a handheld dynamometer (HHD) at various muscle lengths, by modifying the hip and knee angles during testing. DESIGN: Concurrent validity and test-retest reliability. METHODS: Thirty young healthy participants were recruited. Hamstring and quadriceps isometric strength was measured with a HHD and with an isokinetic dynamometer, over 2 testing sessions, in a randomized order. Isometric strength was measured on the right lower limb in 6 different positions, with the hip at either 0° or 80° of flexion and the knee at either 30°, 60°, or 90° of flexion. Pearson and Spearman correlations were used to assess the validity, and intraclass correlation coefficients were calculated to establish the test-retest reliability of the HHD. RESULTS: Good to excellent reliability and moderate to high validity were found in all the tested muscle length positions, except for the hamstrings in a seated position with the knee extended at 30°. CONCLUSIONS: The use of a HHD is supported in the clinical setting to measure knee muscle strength at varying muscle lengths in healthy adults, but not for the hamstrings in a lengthened position (hip flexed and knee extended). These results will have to be confirmed in sport-specific populations.

Dependence of Rotator Cuff Muscle Thickness and Stiffness on Low-Level Contractions: Metrology of the Contraction Level Using Shear-Wave Imaging.

OBJECTIVE: The study aimed to investigate the effects of the level of contraction during isometric shoulder abduction at different abduction angles on muscle thickness and stiffness of the shoulder girdle in asymptomatic individuals. DESIGN: Measurement properties study. SETTING: Biomechanics and motion analysis lab. PARTICIPANTS: Twenty individuals volunteered to participate in this study. MAIN OUTCOME MEASURE: The subjects were tested for morphological and mechanical properties, expressed by thickness and stiffness of the supraspinatus tendon and muscle, and upper trapezius muscle. Moreover, acromiohumeral distance was also evaluated using B-mode ultrasound and shear-wave elastography. INTERVENTION: The thickness and stiffness of the supraspinatus and upper trapezius muscle were assessed at 3 angles of abduction (0°, 60°, and 90°) and 3 levels of contraction (0%, 10%, and 20% of the maximal voluntary isometric contraction) using ultrasonography with shear-wave imaging. Moreover, the acromiohumeral distance was measured to establish the occupation ratio during passive movement. RESULTS: The supraspinatus and upper trapezius muscle thickness and stiffness were significantly greater at 60° shoulder abduction compared with 0°, and 90° compared with 60°, as well as significantly greater at 20% maximal voluntary isometric contraction compared with 0% and 10% maximal voluntary isometric contraction. Thickness and stiffness were significantly greater in the supraspinatus compared with the upper trapezius muscle at all 3 angles of shoulder abduction for all 3 level of contractions. The acromiohumeral distance decreased significantly from 0° to 60° and from 60° to 90°. CONCLUSION: Morphological and mechanical properties of the supraspinatus and upper trapezius muscles depended on the relative level of muscle contraction and the angle of shoulder abduction.

Field Hip Stability Isometric Test (F-HipSIT): Reliability of Assessing the Hip Posterolateral Muscle Strength in Sports Settings.

CONTEXT: The Hip Stability Isometric Test (HipSIT) is commonly employed in clinical settings for evaluating the hip posterolateral muscle strength. In this study, we introduced the "Field Hip Stability Isometric Test" (F-HipSIT) and assessed the intrarater and interrater reliability of this strength assessment specifically designed for sports settings. DESIGN: Reliability study. METHODS: Two independent raters (A and B) went to athletes' training facilities to conduct 2 sessions of F-HipSIT spaced at least 1 week apart. The average peak force value from 3 valid attempts of each leg was recorded and normalized by the participant's body mass for statistical analysis. RESULTS: Thirty male and 30 female amateur athletes took part in this study. Rater A obtained similar values in the first (0.39 [0.05] and 0.44 [0.07] kg·f/kg) and second (0.39 [0.06] and 0.45 [0.07] kg·f/kg) testing days for men and women, respectively. Rater B also found similar values in the first (0.35 [0.06] and 0.42 [0.08] kg·f/kg) and second (0.36 [0.06] and 0.45 [0.08] kg·f/kg) testing days for men and women, respectively. Excellent intrarater intraclass correlation coefficient (ICC) values were found for men (ICC = .922) and women (ICC = .930), with coefficient of variation of 6% to 8% and minimal detectable change of 0.06 to 0.10 kg·f/kg. The F-HipSIT presented good interrater reliability for men (ICC = .857) and women (ICC = .868), with coefficient of variation of 5% and minimal detectable change of 0.05 to 0.06 kg·f/kg. CONCLUSION: The F-HipSIT intrarater and interrater reliability among male and female recreational athletes supports this field test as a quick and convenient screening tool to monitor hip posterolateral muscle strength in sports settings.

Reliability and validity of new isokinetic strength assessment for rotator cuff muscles in a muscle architecture-based position.

Background/aim: Isokinetic strength assessment of the rotator cuff muscle is frequently applied in a variety of shoulder postures, but none of these consider muscular architecture, which is one of the most important aspects of improving strength development. This study aimed to examine the test and retest reliability and validity of the muscle architecture-based position (MABP), which is 25° abduction and 20° external rotation, in healthy subjects to be able to select a better isokinetic assessment position for shoulder rotator cuff muscles. Materials and methods: A total of 54 healthy males with a mean age of 21.0 ± 1.2 years and mean body mass index of 22.8 ± 1.7 kg/m2 completed an isokinetic measurement session. All of the tests were performed on an IsoMed 2000 isokinetic dynamometer concentrically and eccentrically for both upper limbs at 60°/s angular velocity. All of the participants completed 3 measurement sessions: the first represented the isokinetic testing and was performed in the scapular neutral position (SNP) (45° shoulder flexion and abduction), the second represented the MABP (25° abduction and 20° ER) for shoulder rotator cuff muscles, and the third represented the test and retest of the MABP. Results: The correlations between the 2 techniques for assessing concurrent validity ranged from 0.908 to 0.994. The values obtained from the MABP were higher than those obtained in the SNP. There was no systematic bias for any measurements between the MABP and the retest of the MABP (p > 0.05). The intraclass correlation coefficients representing the test and retest reliability results for each variable measured with the MABP was higher than 0.98 and this value was considered as excellent reliability. Conclusion: In conclusion, the MABP can be used to assess the isokinetic strength of the rotator cuff muscles safely and confidently, with increased quantities of force being released and measurement at optimal muscle tension.

Lower extremity muscle strength equation of older adults assessed by Five Time Sit to Stand Test (FTSST).

Background: The decline in lower limb muscle strength, one of the risk factors for falling in the older adults, puts older persons at an increased risk of falling. The assessment of the lower limb muscle strength is very important. Objective: The purpose of this study was to construct the equation for predicting knee extensor muscle strength based on demographic data and the results of the Five-Time Sit-to-Stand Test (FTSST). Methods: A total of 121 healthy elders (mean age 68.00±7.26) were asked to complete the FTSST and submit the demographic information. By using a stationary push-pull dynamometer, the knee extensor strength of each participant was assessed. The multiple regression analysis was used to explore knee extensor strength prediction equation. Results: The findings demonstrated that the knee extensor strength equation was developed using variables obtained from gender, weight, and time to complete the FTSST. The equation was found to have a high correlation (r=0.838) and 70.1% estimation power. Its formula was as follows: Knee extensor strength=32.735+3.688 (gender; female=0 or male=1) + 0.189 (weight) - 2.617 (time to complete the FTSST). However, there was an estimating error in this equation of 4.72 kg. Conclusion: The determining factors influencing knee extensor strength, which can be utilized to estimate the strength in elderly individuals, are demographic variables including gender, weight, and the time taken to complete the FTSST.

Reliability of belt-stabilized handheld or isokinetic dynamometer-based isometric knee-extensor strength-testing when seated with the toes of the contralateral nonexamined side off the floor.

[Purpose] To determine the intra-rater and inter-devices reliability of isometric knee-extensor muscle-strength-measurement. [Participants and Methods] The participants were 77 university students (50 males; 27 females) who underwent isometric knee-extension muscle-strength measurement twice with a belt-stabilized handheld dynamometer and isokinetic dynamometer. The intra-rater and inter-devices reliability was ascertained from measurements that were performed with the participant seated on the edge of the bed, the toes of the contralateral nonexamined side off the floor, and the trunk supported by the upper limb. [Results] In the overall, male, and female cohorts, the 95% confidence intervals of intra-rater reliabilities (1,1) in the belt-stabilized handheld and isokinetic dynamometers were 0.96-0.98, 0.92-0.97, and 0.81-0.96, 0.82-0.92, 0.73-0.90, and 0.78-0.95, respectively, and the inter-device 95% confidence intervals were 0.52-0.77, 0.28-0.69, and -0.03 to 0.63, respectively. Compared to the belt-stabilized handheld dynamometer group, the isokinetic dynamometer group had higher knee-extension muscle strength. [Conclusion] The intra-rater reliability was rated good-to-excellent and moderate-to-excellent for the belt-stabilized handheld and isokinetic dynamometers, respectively. The inter-devices reliability was poor, and isometric knee-extension muscle strength in the isokinetic dynamometer group was higher than that in the belt-stabilized handheld dynamometer group.

Does the objective measurement of muscle strength improve the detection of postoperative residual muscle weakness?

Background and Aims: The postoperative residual neuromuscular block (PRNB) has a significant impact on patient safety and well-being, but continues to remain underestimated. Objective evaluation of handgrip strength using a force dynamometer can be useful to identify postoperative muscle weakness. Material and Methods: Thirty-two American Society of Anesthesiologists (ASA) class I and II patients who received general anesthesia were included. Patients were extubated after the train-of-four (TOR) ratio (TOFR) was >0.90 and the clinical criteria for motor power recovery were judged as adequate. The measurements of handgrip strength and peak expiratory flow rate (PEFR) were obtained at baseline, 15 min after extubation, and 1, 2, and 4 h postoperatively. The incidence of significant decline from baseline (>25%) was determined. The correlation between handgrip strength and PEFR was assessed using Spearman correlation. The time to return to baseline for muscle grip strength and PEFR was performed using Kaplan-Meier survival analysis. A P value of 0.05 was considered significant for all tests. Results: The incidence of the significant decline in handgrip strength from baseline was 100% at 15 and 60 min, 76% at 2 h, and 9.4% at 4 h. There was a strong correlation between muscle grip strength and PEFR (0.89, P < 0.001). None of the patients exhibited the potential complications of PRNB. (PRMB in abstract. It should be uniform) The mean time to return to the baseline value of muscle grip strength was 3.8 h (95% confidence interval [CI] 3.6-3.9), and the mean time to return to baseline for PEFR was 3.2 h (95% CI 2.9-3.4 h). Conclusion: Objective assessment of muscle grip strength using a force dynamometer has the potential to be a new objective metric to monitor postoperative muscle weakness.

Health and sociodemographic factors associated with low muscle strength, muscle mass, and physical performance among people living with HIV.

ABSTRACTThis study examined the factors associated with low muscle strength, muscle mass, and physical performance in 331 people living with HIV. Participants completed handgrip as a strength measure, appendicular skeletal muscle mass using bioimpedance analysis, and chair rise was a physical performance measure. Multivariate logistic regression was used to analyze the association between low values on these measures with sociodemographic, HIV-related factors, and comorbidities. Higher body mass index (BMI) (OR = 0.91; CI = 0.86-0.97) and higher CD4/CD8 ratio (OR = 0.38; 95% CI = 0.18-0.82) were associated with decreased likelihood of low handgrip strength. Being non-employed (OR = 2.08; 95% CI = 1.07-4.06), having hypertension (OR = 2.27; 95% CI = 1.13-4.54) and rheumatism (OR = 5.46; 95% CI = 1.68-17.74) increased the chance of low handgrip strength. Higher BMI (OR = 0.43; 95% CI = 0.34-0.56), CD4/CD8 ratio (OR = 0.29; 95% CI = 0.09-0.93), and bioimpedance phase angle (OR = 0.22; 95% CI = 0.12-0.40) were associated with decreased likelihood of low muscle mass. Lastly, having less than eight years of education (OR = 1.87; 95% CI = 1.02-3.41) and being non-employed (OR = 8.18; 95% CI = 3.09-21.61) increased the chance of low chair stand performance. In addition, higher CD4 + lymphocytes count (OR = 0.99; 95% CI = 0.99-0.99) was associated with a decreased likelihood of low chair stand performance. In conclusion, specific and non-specific HIV-related factors are associated with low handgrip strength, low muscle mass, and/or low chair stand performance.

Characterizing Operating Condition-Based Formaldehyde Emissions of Light-Duty Diesel Trucks in China Using a PEMS-HCHO System.

Formaldehyde (HCHO) plays a critical role in atmospheric photochemistry and public health. While existing studies have suggested that vehicular exhaust is an important source of HCHO, the operating condition-based diesel truck HCHO emission measurements remain severely limited due to the limited temporal resolution and accuracy of measurement techniques. In this study, we characterized the second-by-second HCHO emissions from 29 light-duty diesel trucks (LDDTs) in China over dynamometer and real-world driving tests using a portable online HCHO emission measurement system (PEMS-HCHO), considering various operating conditions. Our results suggested that the HCHO emissions from LDDTs might be underestimated by the widely used offline DNPH-HPLC method. The HCHO emissions at a 200 s cold start from China V LDDT can be up to 50 mg/start. Different driving conditions over dynamometer and real-world driving tests led to a 2-4 times difference in the HCHO emission factors (EFs). Under real-world hot-running conditions, the HCHO EFs of China III, IV, V, and VI LDDTs were 43.5 ± 35.7, 10.6 ± 14.2, 8.8 ± 5.1, and 3.2 ± 1.2 mg/km, respectively, which significantly exceeded the latest California low emission vehicle III HCHO emission standard (2.5 mg/km). These findings highlighted the significant impact of vehicle operating conditions on HCHO emissions and the urgency of regulating HCHO emissions from LDDTs in China.

Exceedances of Secondary Aerosol Formation from In-Use Natural Gas Heavy-Duty Vehicles Compared to Diesel Heavy-Duty Vehicles.

This work, for the first time, assessed the secondary aerosol formation from both in-use diesel and natural gas heavy-duty vehicles of different vocations when they were operated on a chassis dynamometer while the vehicles were exercised on different driving cycles. Testing was performed on natural gas vehicles equipped with three-way catalysts (TWCs) and diesel trucks equipped with diesel oxidation catalysts, diesel particulate filters, and selective catalytic reduction systems. Secondary aerosol was measured after introducing dilute exhaust into a 30 m3 environmental chamber. Particulate matter ranged from 0.18 to 0.53 mg/mile for the diesel vehicles vs 1.4-85 mg/mile for the natural gas vehicles, total particle number ranged from 4.01 × 1012 to 3.61 × 1013 for the diesel vehicles vs 5.68 × 1012-2.75 × 1015 for the natural gas vehicles, and nonmethane organic gas emissions ranged from 0.032 to 0.05 mg/mile for the diesel vehicles vs 0.012-1.35 mg/mile for the natural gas vehicles. Ammonia formation was favored in the TWC and was found in higher concentrations for the natural gas vehicles (ranged from ∼0 to 1.75 g/mile) than diesel vehicles (ranged from ∼0 to 0.4 g/mile), leading to substantial secondary ammonium nitrate formation (ranging from 8.5 to 98.8 mg/mile for the natural gas vehicles). For the diesel vehicles, one had a secondary ammonium nitrate of 18.5 mg/mile, while the other showed essentially no secondary ammonium nitrate formation. The advanced aftertreatment controls in diesel vehicles resulted in almost negligible secondary organic aerosol (SOA) formation (ranging from 0.046 to 2.04 mg/mile), while the natural gas vehicles led to elevated SOA formation that was likely sourced from the engine lubricating oil (ranging from 3.11 to 39.7 mg/mile). For two natural gas vehicles, the contribution of lightly oxidized lubricating oil in the primary organic aerosol was dominant (as shown in the mass spectra analysis), leading to enhanced SOA mass. Heavily oxidized lubricating oil was also observed to contribute to the SOA formation for other natural gas vehicles.