Handheld dynamometer reliability to measure knee extension strength in rehabilitation patients—A cross-sectional study

Impact of professional experience on clinical judgment and muscular response in various neuromuscular tests

Muscle testing is an integral component in assessing musculoskeletal function and tailoring rehabilitation efforts. This study aimed i. to identify an objective evaluation system sensitive to analyze changes in different muscular conditions in different neuromuscular tests across a spectrum of professional experience levels; and ii. to analyze differences in objective parameters and clinical judgment between participants of different levels of expertise in different muscular conditions in different neuromuscular tests. Participants included 60 subjects with Level I to III expertise who performed blinded neuromuscular tests on the middle deltoid and rectus femoris muscles of 40 volunteer subjects. The methodology centered on standardizing test protocols to minimize variability, employing EMG to quantify muscle activity, thermography to capture thermographic muscular response, and digital dynamometry to measure muscular resistance. The findings revealed that while traditional methods like thermography and electromyography provide valuable insights, digital dynamometry stands out for its sensitivity in detecting muscle condition changes in neuromuscular test. Moreover, the data underscored the pivotal role of advanced training and expertise in enhancing the precision and accuracy of neuromuscular diagnostics, since there were significant differences in objective parameters and clinical judgment between participants of different levels of expertise in the different muscular conditions in Middle deltoid and Rectus femoris neuromuscular tests analyzed, presenting higher expertise participant clinical judgment like objective validated instrument.

Cut-off points for knee extension strength: identifying muscle weakness in older adults

PURPOSE

Generalized muscle weakness is the primary characteristic of sarcopenia. Handgrip strength (HGS) is widely employed to detect muscle weakness. However, knee extension strength (KES) declines much earlier and more pronounced than HGS, and there is a stronger correlation between KES and functional performance. Therefore, KES may be a more appropriate proxy for identifying muscle weakness compared to HGS. The purpose of this review was to clarify the KES measurement towards a standardized approach and summarize the cut-off points for KES.

METHODS

A literature search was conducted in Web of Science, PubMed, Elsevier, Scopus and Medline databased up to July 10th, 2023.

RESULTS

A total of 12 articles were ultimately included in this review, which proposed various cut-off points for KES. Notably, these studies exhibited high heterogeneities, including diverse living settings for participants, KES measurement, methods for KES normalization, methodologies for determining cut-off points and study designs.

CONCLUSIONS

No consensus on cut-off points for KES was reached due to the heterogeneities in KES measurement and normalized methods among studies. To enhance the comparability among studies and facilitate the sarcopenia screening framework, a standardized approach for KES measurement and KES normalization are needed. Regarding KES measurement, the hand-held dynamometer-based isometric KES is easy to access and ideally suited for both clinical and community settings, while isokinetic KES, representing the gold standard, is preferred for research settings. Additionally, it is suggested to normalize isometric KES to body weight (BW), while normalizing isokinetic KES to allometrically scaled BW.

Age-specific comparisons in the rate of force development of toe pressure strength and its association with the timed up and go test

PURPOSE

It has recently been recommended that Rate of Force Development (RFD) be evaluated in addition to maximal muscle strength. There are no studies on RFD of toe pressure strength, and its importance in older adults and the extent to which it is associated with aging needs to be clarified. This study purpose was to examine the association between the RFD of toe pressure strength and timed up and go test (TUG) in an age-specific study.

METHODS

This study is a cross-sectional study. Participants in the study included 159 younger adults (26.3 ± 13.1 years, 52% male) and 88 older adults (75.0 ± 6.2 years, 26% male). The RFD of toe pressure strength was determined from the force-time curve obtained during the toe pressure strength assessment, and the ability to exert maximum muscle force in the shortest possible time was assessed. Regression analysis was performed for each group to test the association between RFD of toe pressure strength and TUG by age.

RESULTS

Younger adults showed no association between TUG and RFD of toe pressure strength, and significant association between TUG and RFD of toe pressure strength was found only in the older adults (standard regression coefficient =  - 0.19, p = 0.048).

CONCLUSION

This study showed a significant association between TUG and RFD of toe pressure strength in older adults. These findings show that RFD is one of the functions that should be assessed, particularly in older adults. Furthermore, it was suggested that approaching RFD could improve gait, standing, and sitting movements.

Cartilage oligomeric matrix protein as a potential biomarker for knee osteoarthritis

Aims

This study aimed to determine the expression and clinical significance of a cartilage protein, cartilage oligomeric matrix protein (COMP), in knee osteoarthritis (OA) patients.

Methods

A total of 270 knee OA patients and 93 healthy controls were recruited. COMP messenger RNA (mRNA) and protein levels in serum, synovial fluid, synovial tissue, and fibroblast-like synoviocytes (FLSs) of knee OA patients were determined using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunohistochemistry.

Results

COMP protein levels were significantly elevated in serum and synovial fluid of knee OA patients, especially those in the advanced stages of the disease. Serum COMP was significantly correlated with radiological severity as well as measures of body composition, physical performance, knee pain, and disability. Receiver operating characteristic curve analysis unveiled a diagnostic value of serum COMP as a biomarker of knee OA (41.64 ng/ml, area under the curve (AUC) = 1.00), with a sensitivity of 99.6% and a specificity of 100.0%. Further analysis uncovered that COMP mRNA expression was markedly upregulated in the inflamed synovium of knee OA, consistent with immunohistochemical staining revealing localization of COMP protein in the lining and sub-lining layers of knee OA inflamed synovium. Most notably, relative COMP mRNA expression in knee OA synovium was positively associated with its protein levels in serum and synovial fluid of knee OA patients. In human knee OA FLSs activated with tumour necrosis factor-alpha, COMP mRNA expression was considerably up-regulated in a time-dependent manner.

Conclusion

All results indicate that COMP might serve as a supportive diagnostic marker for knee OA in conjunction with the standard diagnostic methods.

Test-retest reliability and concurrent validity of knee extensor strength measured by a novel device incorporated into a weight stack machine vs. handheld and isokinetic dynamometry

BACKGROUND

The current clinical gold standard for assessing isometric quadriceps muscle strength is an isokinetic dynamometer (IKD). However, in clinics without an IKD, clinicians default to using handheld dynamometers (HHD), which are less reliable and accurate than the IKD, particularly for large muscle groups. A novel device (ND) was developed that locks the weight stack of weight machines, and measures forces applied to the machine, turning this equipment into an isometric dynamometer. The objectives of this study were to characterize the test-retest reliability of the ND, determine the within-day and between-days inter-rater reliability and concurrent validity compared with that of the HHD, in healthy volunteers (HV) and individuals with knee osteoarthritis (OA) for measuring knee extensors isometric muscle force.

MATERIALS AND METHODS

29 healthy (age = 28.4 ± 7.4 years) and 15 knee OA (age = 37.6 ± 13.4 years) participants completed three maximum force isometric strength testing trials on dominant side knee extensor muscles on three devices (ND, HHD, and IKD) in two separate sessions by two raters. The maximum force (Fmax) produced, and the force-time series were recorded. Reliability and validity were assessed using Intraclass Correlation Coefficient (ICC), Bland-Altman Plots, Pearson's r, and cross-correlations.

RESULTS

The ND demonstrated excellent test-retest reliability (ICC2,3 = 0.97). The within-day (ICC2,3 = 0.88) and between-day inter-rater reliability (ICC2,3 = 0.87) was good for HHD. The ND showed excellent within-day (ICC2,3 = 0.93) and good between-day (ICC2,3 = 0.89) inter-rater reliability. The Bland-Altman analysis revealed HHD systematic bias and underestimation of force particularly with quadriceps force values exceeding 450 N. Mean differences were found in maximum force between HHD vs. IKD (MDabs = 58 N, p < .001) but not the HHD vs. ND (MDabs = 24 N, p = .267) or ND vs. IKD (MDabs = 34 N, p = .051). The concurrent validity of Fmax (r = 0.81) and force-time curve correlation (0.96 ± 0.05) were the highest between the ND and IKD.

CONCLUSIONS

The ND's test-retest reliability and concurrent validity make it a potential strength assessment tool with utility in physical therapy and fitness settings for large muscle groups such as the knee extensors.

Improvement of muscle quality assessed using the phase angle is influenced by recovery of knee extension strength in patients with hip fractures

BACKGROUND AND AIMS

Studies reported that knee extension strength on the operated side in patients with hip fractures was not recovered to the level on the non-operated side 6 months after surgery or later. In a cross-sectional study, we revealed that a reduction in isometric knee extension muscle strength on the operated side in patients with hip fractures approximately 6 months after surgery was associated with not only a reduction in skeletal muscle mass but also a reduction in muscle quality, characterized by a reduction in the phase angle (PhA). Furthermore, the mechanisms of knee extension strength improvement can be clarified in more detail using the minimal significant change as the index of recovery. However, no longitudinal studies have examined the factors for knee extension strength improvement based on the minimal significant change in patients with hip fractures 6 months after surgery. This study aimed to longitudinally examine the factors influencing the recovery of knee extension strength based on the minimal significant change in patients with hip fractures between 2 weeks and approximately 6 months after surgery.

METHODS

In this study, the outcomes used were basic and medical information, PhA, skeletal muscle index (SMI), pain, one-leg standing time, movement control during one-leg standing, and walking speed. For PhA, SMI, pain, one-leg standing time, movement control during one-leg standing, and walking speed, the amount of change was calculated by subtracting the data at 2 weeks from the data at 6 months. Group classification was determined by dividing the patients into two groups using a previous study as a reference: recovery group if the knee extension strength value approximately 6 months after surgery minus that 2 weeks after surgery was ≥3.3 kgf and non-recovery group if the value was <3.3 kgf. Logistic regression analysis was performed to explore the association between the recovery and non-recovery groups.

RESULTS

The recovery group contained 55 patients, while the non-recovery group comprised 35 patients. The only significant factor associated with knee extension muscle strength in the recovery group was the amount of change in PhA. The odds ratio for the amount of change in PhA was 2.26. The discrimination rate of the model was 62.5%.

CONCLUSIONS

Our results suggest that recovery of knee extension strength in patients with hip fractures after surgery was mainly because of improvements in muscle quality, not improvements in muscle mass or pain.

Effect of combined Kinesiotaping and resistive exercise on muscle strength and quality of life in breast cancer survivors: a randomized clinical trial

BACKGROUND

Breast cancer (BC) and its treatment affect women's tissue architecture and physiology, which leads to impaired muscle strength and joint dysfunction, affecting quality of life (QOL). Most evidence has focused on exercises; however, due to the complexity and heterogeneity of patients' rehabilitation needs, further research is required to investigate more adjunctive methods to help optimal rehabilitation according to patients' needs, preferences, and effective interventions.

METHODS

This study aimed to determine the effect of Kinesiotaping (KT) combined with resistive exercise on muscle strength and QOL in breast cancer survivors (BCS). Forty premenopausal BCS treated with chemotherapy postmastectomy participated in this study. Their age ranged from 40 to 55 years, and their body mass index (BMI) was 25-29.9 kg/m2. They were randomly distributed into two equal groups. The control group received resistive exercise two times/week for 12 weeks, while the study group received resistive exercise and KT applied to the lower limbs. Hip, knee, and ankle muscle strength were measured using a hand-held dynamometer, and QOL was evaluated using 36-Item Short Form (SF-36) before and after treatment.

RESULTS

Both groups showed a significant increase (p = 0.0001) in the strength of hip flexors, knee extensors, flexors, ankle plantar flexors, and dorsiflexors, as well as SF-36 score after treatment. However, the study group showed a more significant increase in strength of hip flexors (p = 0.005), knee extensors (p = 0.01) and flexors (p = 0.02), ankle plantar flexors (p = 0.01), and dorsiflexors (p = 0.01), as well as SF-36 score (p = 0.006) than the control group.

CONCLUSIONS

KT plus resistive exercise is more effective than exercise alone for improving muscle strength and QOL in BCS. So, the KT can be recommended as a non-invasive, adjunctive method added to the protocol therapy for BCS to help better outcomes during the rehabilitation period.

Effectiveness of an online management platform (Joint Cloud) versus standard process for patients undergoing total knee arthroplasty: study protocol for a prospective randomised controlled trial

INTRODUCTION

Osteoarthritis (OA) is one of the main causes of mobility impairment in the elderly worldwide. Therefore, total knee arthroplasty (TKA) is often performed and is one of the most successful surgery and has resulted in substantial quality-of-life gains for people with end-stage arthritis. There is still room for improvement in the standard treatment process in the preoperative, intraoperative and postoperative period of TKA. Telerehabilitation has the potential to become a positive alternative to face-to-face rehabilitation nowadays. But it remains unclear how well telemedicine interventions cover the entire surgical pathway (preoperation, intraoperation, postoperation). This study aims to explore the effectiveness of Joint Cloud (JC, an online management platform) compared with existing standard process in regulating functional recovery, pain management, muscle strength changes and other health-related outcomes in patients undergoing total knee arthroplasty preoperation, intraoperation and postoperation.

METHODS AND ANALYSIS

A randomised controlled trial was designed to compare the online management platform (JC) with standard process (SP) in patients undergoing TKA. A total of 186 TKA patients will be randomly assigned to the intervention (n=93) or control (n=93) group. Patients in the intervention group will receive access to the 'JC' mini-program. This mini-program provides popular science information (eg, information about OA and TKA), functional exercise information and communication channels. Patients evaluate their condition and functional level through standardised digital questionnaires. The control group of patients will not accept any functions of this mini-program. The primary outcome is knee functional recovery, and the secondary outcomes are pain management, isometric knee extensor muscle strength, patient satisfaction and cost-benefit analysis. Assessments will be performed 1 month and 3 days before surgery (T0) and 1 month and 3 months after surgery. Data analysis will be performed according to the intent-to-treat (ITT) principle. Repeated measures of linear mixed models and parametric and non-parametric testing will be used for statistical analysis.

ETHICS AND DISSEMINATION

The study was reviewed and approved by the Tianjin Hospital Medical Ethics Review Committee on 10 February 2023 (2022YLS155). Test data are considered highly sensitive but are available upon request. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR2300068486.

Motor Strength Measurements Obtained Using an Inexpensive Spring Tensiometer and a Clinical Dynamometer Correlated Well: A Prospective Cohort Study

OBJECTIVE

Manual muscle strength testing is the primary method for testing muscle strength in clinical settings but is highly subjective. An objective measure of muscle strength can be obtained using a handheld dynamometer, but its cost inhibits its widespread usage. We hypothesized that a spring tensiometer (ST) could be an objective tool that can be used as a viable alternative to a dynamometer.

METHODS

Twenty-six outpatients were included, and the strengths of several muscle groups were measured using tensiometers and dynamometers. A paired t-test and Pearson's correlation coefficient and Bland-Altman plot analyses were used to estimate the reliability and measurement accuracy of both tools. Multiple regression analysis was performed to identify the factors contributing to the measurement gap between the two instruments.

RESULTS

A total of 260 muscle force values were evaluated. Pearson's correlation coefficient and Bland-Altman analyses indicated that the measurements of the two instruments were strongly correlated and highly accurate. In the multiple regression analysis, the gap between the two instruments was significantly related to the original muscle strength and muscle part but was not significantly related to sex, age, body mass index, or laterality. For biceps and triceps muscle groups, the correlations were particularly strong and accurate, indicating that a tensiometer could be well substituted for a dynamometer.

CONCLUSIONS

Our data show that a ST is similar to a dynamometer in terms of precision. A ST is an inexpensive alternative to a dynamometer and more accessible for clinical use than a dynamometer.

Association Between Knee Extension Strength and Functional Capacity After Intensive Care Unit Discharge: A 6-Mo Prospective Cohort Study

INTRODUCTION

Assessing functional improvement after intensive care unit discharge is particularly challenging. The aim of this study was to measure the association between (1) changes in knee extension muscle strength or quadriceps femoris and rectus femoris muscle thickness and (2) changes in functionality/function-related measurements in post-intensive care unit patients.

METHODS

This prospective cohort study included adult patients without previous disability, consecutively selected after intensive care unit discharge. Some parameters, such as Short-Form 36, 6-min walking test, 1-min sit-to-stand, and Short Physical Performance Battery, were measured at baseline and 3 and 6 mos after discharge. Correlations were assessed and regression models were built to assess the association between evolution in knee extension strength or muscle thickness and evolution in functional tests.

RESULTS

Thirty patients completed the follow-up. Moderate correlation was found between knee extension strength change and Short-Form 36 physical functioning (correlation coefficient [ ρ ] = 0.53), 6-min walking test ( ρ = 0.38), 1-min sit-to-stand ( ρ = 0.52), and Short Physical Performance Battery ( ρ = 0.38). Baseline values and changes in knee extension strength moderately predicted evolution in Short-Form 36 physical functioning ( r2 = 0.32, P = 0.006). Changes in muscle thickness were overall not associated with changes in functional variables.

CONCLUSION

Changes in knee extension muscle strength may inform on functional progression over time after intensive care unit discharge, although confirmatory studies are needed.

Comparison of toe pressure strength in the standing position and toe grip strength in association with the presence of assistance in standing up: a cross-sectional study in community-dwelling older adults

PURPOSE

We believe that toe pressure strength in the standing position, which is closer to the actual movement, is more associated with standing up in the older adults than the conventional toe grip strength. Therefore, the purpose of this study is to examine the association between toe pressure strength in the standing position and the presence of assistance in standing up in the older adults.

METHODS

Ninety-five community-dwelling older adults (82 ± 8 years old, 72% female) were included in this study. The patients were evaluated based on their need for assistance in standing up. Physical functions, including toe pressure strength in the standing position, toe grip strength, hand grip strength, knee extension strength, one-leg standing time with eyes open, and maximal walking speed, were measured.

RESULTS

When compared with and without assistance to stand up, the group requiring assistance had weaker toe pressure strength in the standing position than the group without assistance (p = 0.015, ES = 0.53). After adjusting for confounding factors, the final model revealed that toe pressure strength in the standing position was associated with the use of assistance in standing up (odds ratio 0.94 [0.88-0.99, p = 0.025]).

CONCLUSION

Toe pressure strength in the standing position was associated with the use of assistance in standing up in older adults. Improving toe pressure strength in the standing position may facilitate the ability of older adults to stand up.

A 1-Week Comprehensive Foam Rolling Intervention Program Can Improve Knee Pain but Not Muscle Function and Range of Motion in Patients with Total Knee Arthroplasty

We investigate the effect of a 1-week comprehensive foam rolling (FR) intervention program on knee pain, range of motion (ROM), and muscle function in patients with TKA.Thirty patients with TKA were randomly allocated to FR (n = 15) or control (n = 15) groups. The control group received only regular physical therapy. Patients in the FR group performed the FR intervention in addition to their regular physical therapy twice daily from postoperative weeks two to three (60 s × 3 repetitions × 2 times/day × 6 days: total = 2160 s). Pain score, knee flexion and extension ROM, muscle strength, walking function, and balance function were measured before and after the FR intervention. From the second to third postoperative weeks, there were significant improvements in all variables, and the reduction in pain score at stretching was significantly greater in the FR group (-26.0 ± 1.4; p < 0.05) than in the control group (-12.5 ± 1.9). However, there was no significant difference in changes in the other variables except for the pain score at stretching between FR and control groups. A 1-week comprehensive FR intervention program in patients with TKA could reduce pain scores at stretching without a synergistic effect on physical function, i.e., walking speed, balance function, and muscle strength of the knee extensors muscles.