Reference Values for Concentric Knee Isokinetic Strength and Power in Nonathletic Men and Women from 20 to 80 Years Old (original) (raw)
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Isokinetics and Exercise Science, 2007
The purpose of this study was to determine the reproducibility of measures for maximum knee extensor and flexor concentric strength on an isokinetic dynamometer in individuals with mild and moderate osteoarthritis of the knee. Twenty eight female patients with 1 st (n = 14) and 3 rd (n = 14) grade unilateral knee OA volunteered for the study. Peak muscle torque of the knee extensors and flexors was measured using an isokinetic dynamometer at angular velocities of 90, 120 and 150 • /s. Test-retest reproducibility of maximal isokinetic torque was evaluated using intraclass correlation coefficient (ICC). Absolute reproducibility was assessed using Bland-Altman analysis, the standard error of measurement (SEM and SEM%) and the smallest real differences (SRD & SRD%). Inter-session relative reproducibility was found to be high in extensor and flexor muscles of individuals with mild OA, with the ICCs values ranging from 0.89 to 0.92 for the concentric knee extension and from 0.90 to 0.93 for the concentric knee flexion, while in the group of individuals with moderate knee OA the same values varied from 0.79 to 0.91 and from 0.75 to 0.93 for the concentric knee extension and flexion, respectively. The Bland-Altman analyses support the findings of high relative reproducibility for the two groups of patients in almost all measurements, except for the extension at 120 and 90 • /s and the flexion at 150 • /s conducted by the individuals with moderate OA. SEM and relative SEM values ranged from 6.7 to 9.4 Nm and from 14.4% to 21.5%Nm for the group with mild OA and from 4.4 to 7.7 Nm and from 14.6% to 21.8%Nm for the group with moderate OA, respectively. SRD and SRD% values across all movement speeds for both knee flexors and extensors ranged from 18.6 to 26.1 Nm and from 39.9% to 59.6%Nm for the mild OA group, respectively, while the same values for the moderate OA group ranged from 12.2 to 21.3 Nm and from 40.5% to 56.8%Nm, respectively. These results indicate that measurements of isokinetic performance at velocities of 90, 120 and 150 • /s provide acceptable reproducibility for evaluation of knee strength in individuals with mild OA of the knee. On the other hand, with regard to knee muscles isokinetic performance, testing of individuals with moderate OA should be conducted during periods of time when the symptoms of the disease subside.
Physical therapy in sport : official journal of the Association of Chartered Physiotherapists in Sports Medicine, 2012
To assess the reproducibility of isokinetic eccentric and concentric knee extension and flexion strength indices obtained at two different angular velocities. Cohort study. University human performance laboratory. 45 healthy physically active young adults (25 males). A non reciprocal protocol of concentric and eccentric contractions of the knee extensors and flexors was performed at 30 and 120°/s. Strength indices evaluated included peak moment; dynamic control ratios; and the difference between eccentric and concentric ratio at the two angular velocities. No evidence for inter-test bias in any of the strength indices was noted. Measurement precision for peak moment, as quantified using ratio limits of agreement, suggest that scores may be expected to vary up to 15% for the knee extensors in both eccentric and concentric contraction modes. An error of up to 19% was calculated for the peak moment scores of the knee flexors. Intraclass correlation coefficients revealed fairly robust p...
PloS one, 2018
The current study aimed to examine the reliability of the conventional and functional ratios derived from peak torques (PTs) and those obtained from the combination of knee flexors torque at the angle of knee extensors PT. Twenty-six male athletes (mean of 24.0±0.7 years) from different sports completed a test-to-test variation in isokinetic strength (Biodex, System 3) within a period of one week. Anthropometry and body composition assessed by Dual Energy X-ray Absorptiometry were also measured. The proposed isokinetic strength ratio measurements appeared to be highly reliable: conventional ratio at PT angle (intra-class correlation, ICC = 0.98; 95% confidence interval; 95%CI: 0.95 to 0.99); functional extension ratio at PT angle (ICC = 0.98; 95%CI: 0.96 to 0.99); and, functional flexion ratio at PT angle (ICC = 0.95; 95%CI: 0.89 to 0.98). Technical error of measurement (TEM) and associated percentage of the coefficient of variation (%CV) were as follows: conventional ratio at PT an...
Journal of Physical Therapy Science, 2018
The main purpose of the study was to examine the relationship of a battery of frequently used functional assessment tests with quadriceps and hamstrings isokinetic strength in Knee-osteoarthritis (OA) patients. Secondarily, the predictability of isokinetic strength on these performance variables was also assessed. [Subjects and Methods] Seventeen males and 23 females with Knee-OA, were assessed via a) the common functional tests: 6-minute walk test, Timed up-and-go test, 30-second chair test and 12-stair test and b) isokinetic concentric extension-flexion at 120°/s and 180°/s. [Results] Both Knee Extension and Flexion Peak Torque per Body weight showed moderate to strong, statistically significant correlation, with all 4-functional performance tests, for both velocities. Both 12-stair test and 30-second chair test were significant predictors in all analyses, while the 6-minute walk test was an additional significant predictor of the 120°/s knee flexion. [Conclusion] Thigh muscle strength in both tested velocities proved to be significantly correlated with functional performance. The 12-stair test and 30-second chair test results were significant predictors for isokinetic extension and flexion in both velocities. It appears that those two tests challenge the knee and the surrounding musculature in a manner that reflects muscle strength.
International journal of physiotherapy, 2020
Background: Strength measurement is an essential component of assessment in rehabilitation. However, there may be many factors that may alter muscle performance, among which anthropometric values play a significant role. Therefore, the objective of this study is to find out the correlation between thigh anthropometric measurements with the knee isokinetic muscle performance. Methods: Eighteen young, healthy male adults, whose mean age was of 21.22 ± 1.39 were included. Anthropometric measurements like height, weight, thigh girth, and femoral length were correlated with isokinetic strength of knee flexor and extensor muscles. The variables collected in isokinetic measurements; used for analysis were peak torque at three angular velocities of 60°/s, 120°/s, and 180°/s. Results: The Pearson correlation between the thigh girth and isokinetic peak torque at angular velocities of 600/s, 1200/s, and 1800/s for knee extensors were, r = 0.52, 0.69 and 0.73 whereas for knee flexors it was r =...
Test-retest reliability of reciprocal isokinetic knee extension and flexion peak torque measurements
Journal of athletic training, 1992
Our purpose in conducting this study was to estimate the reliability of reciprocal concentric knee extension and flexion peak torque obtained in uninjured male athletes using the Biodex isokinetic dynamometer. Twenty-six male intercollegiate athletes (age=19.5+/-4.1 yr; ht=70.3+/-14.9 in; wt=212.9+/-48.5 lb) participated in this study. We used the Biodex to measure peak torque occurring during right knee extension and flexion over 3 consecutive days. Means and standard deviations were calculated for both extension and flexion on each of the 3 days. We observed a significant main effect for days for both extension and flexion. Mean peak torque for the first day was significantly higher (Turkey, p<.05) than the means for the other 2 days, which were not significantly different from each other (Turkey, p>0.05). Intraclass correlation coefficients (ICCs) were estimated for each of the six trials on each of the 3 days. Intraclass correlation coefficients (ICCs) ranged from .88 on t...
Isokinetic quadriceps peak torque, average power and total work at different angular knee velocities
Isokinetic dynamometry offers distinct advantages, both clinically and for research, in the evaluation and treatment of muscle performance .previous research has reported a high level of correlation between peak torque and work and between peak torque and power in the muscles surrounding normal and selected pathological knees. No research to date has examined whether such similarities exist in clients with no pathology to the knee in elderly with certain testing conditions. The purpose of this study was to investigate the relationship between the isokinetic parameters of peak torque PT, work, and power for the extensor muscle groups of elderly female. The main aim was to ascertain how the angular velocity can affect the relation between peak torque, average power and total work. Subjects, materials and methods: Isokinetic data were collected from 60 females; mean age 68.6 years on a Biodex isokinetic testing and training dynamometer at the speeds of 60, and°180, /sec. suggest that peak torque is representative of work and power and may be the only necessary parameter for isokinetic muscle performance testing of the extensor muscles of the knee in elderly.
Establishing Reference Values for Isometric Knee Extension and Flexion Strength
Frontiers in Physiology
Single-joint isometric and isokinetic knee strength assessment plays an important role in strength and conditioning, physical therapy, and rehabilitation. The literature, however, lacks absolute reference values. We systematically reviewed the available studies that assessed isometric knee strength. Two scientific databases (PubMed and PEDro) were searched for the papers that are published from the inception of the field to the end of 2019. We included studies that involved participants of both genders and different age groups, regardless of the study design, that involved isometric knee extension and/or flexion measurement. The extracted data were converted to body-mass-normalized values. Moreover, the data were grouped according to the knee angle condition (extended, mid-range, and flexed). A meta-analysis was performed on 13,893 participants from 411 studies. In adult healthy males, the pooled 95% confidence intervals (CI) for knee extension were 1.34–2.23Nm/kg for extended knee ...
Examination of Isokinetic Strength Rates of Knee Joint (H/Q) in Football Players
JOURNAL OF SOCIAL SCIENCE RESEARCH, 2016
The purpose of this study is to examine the isokinetic strength rates of knee joint (H/Q) in football players.30 males (15 football players, 15 controls) were included in the research who were studying in Yaşar Doğu Sports Sciencies faculty of Ondokuz Mayıs University. The position, age and dominant leg information of the subjects were determined by filling in personal information forms given to the subjects. Body mass index measurements were recorded with a Gaia 359 plus body analyzer and H/Q force rates were measured and recorded with a Humac Norm Cybex Brand computer controlled isokinetic dynamometer at angles of 60osn-1, 180osn-1 and 240osn-1. For the statistical analysis of the data used SPSS 22.0 software was used. Independent t-test was applied for the analysis of football player-control group and dominant leg results. In addition, one-way variance analysis and LSD test were used for repeated measures to compare football players according to their positions. Statistical re...