Isometric Strength Database for Muscle Maximal Voluntary Endurance Field Tests: Normative Data

Abstract

Background Different field tests are used to evaluate muscle capacity, in particular maximal voluntary isometric endurance. However, although there are some normative values for a few muscle endurance tests, these do not consider the weight, height, gender, or age of individuals, which are well-known factors that influence muscle performance. Hypothesis/Purpose The purpose of this study was to investigate the test–retest reproducibility of eight field tests and establish muscle endurance norms, in a healthy population, based on their anthropometric characteristics, which could allow the optimal evaluation of the entire muscle function in a quick manner. Design Case series. Methods This study was conducted in two phases. The first phase was to check the reproducibility inter- and intra-assessor for eight isometric muscle field tests on 20 volunteer subjects aged 40.9 ± 11.6 years old (age range, 21–58 years). The second part was to establish muscle maximal voluntary isometric endurance norms according to these tests on a total of 400 healthy participants grouped by age (50 males and females in each of the age brackets, 20–29; 30–39; 40–49; 50–59 years old, for a total of 200 males and 200 females). Results The intra- and inter-assessor reproducibility tests are good for all muscle measurements (the intraclass correlation coefficients varied between 0.915 and 0.996 and the coefficient of variation between 3.6 and 11.8%). The area under the receiver operating characteristic curves demonstrates a good sensibility with values greater than 0.7 for each test. Each muscle belt presents same ratio regardless of the age and gender group. The simultaneous multiple regression analyses highlight that the anthropometric characteristics of subjects influence significantly the performance of isometric tests. Conclusion This study has permitted establishing prediction equations in a healthy population according to their anthropometric characteristics as well as agonist/antagonist ratios for eight muscle isometric field tests after demonstrating a good reproducibility of all tests.

The Improvement of Trunk Muscle Endurance in Adolescents with Idiopathic Scoliosis Treated with ScoliBrace® and the ScoliBalance® Exercise Approach

“…The post-treatment medians in this study are mostly consistent with those reported in the literature [41][42][43][44][45][46]. For TE, a cross-sectional study of 9413 Danish school students (mean age of 17 years, SD = 0.6) was 147.9 s (SD = 57.3) for males and 148.9 s (SD = 66.9) for females [47].…”

“…More recently, norms for TE were reported as a mean of 181.0 s (±66.8) for males and a mean of 183.2 s (±92.8) for females, which are longer than those seen in the TE baseline times in our study [42]. However, these means were established from 20 volunteers aged 40.9 ± 11.6 years old, ranging in age from 21 to 58 years, who had no history of acute or chronic back disease, and therefore were not representative of our study sample [42].…”

“…Excluding the patients that were able to reach the maximum threshold of 180 s reduced this median slightly to 81.5 s (Table 3). The literature shows varied means ranging from 101 to 123 s in adult populations without scoliosis [42,43,46]. Again, it is possible that the trunk changes in AIS patients were the reason for the lower baseline performance of our patients, and the influence of age cannot be determined from these data.…”

Assessing quadriceps strength in patellofemoral pain patients: A study on the reliability and validity of a low-cost load-cell for clinical practice

“…Given that people with PFP can be divided into different subgroups, depending on the individual aetiologies [15], it is important to determine whether quadriceps weakness is part of the cause for PFP in the individual, and to track whether progress is made when conducting an exercise program to improve quadriceps strength [15]. Presently, the ‘gold standard’ instrument for the evaluation of quadriceps strength is the isokinetic dynamometer (ID) [16,17], which is beyond the affordability of most clinicians (∼R500k-R1.50mil). Although a more reasonable alternative to the ID exists, such as a handheld dynamometer (HHD) [17], the reliability of an HHD depends on the strength and aptitude of the practitioner [18,19].…”

Assessing quadriceps strength in patellofemoral pain patients: A study on the reliability and validity of a low-cost strain-gauge for clinical practice

“…Moreover, it is also essential to track whether progress is made when conducting an exercise program to improve quadriceps strength such that more sound and robust clinical decisions can be made [ 15 ]. Presently, the ‘gold standard’ instrument for the evaluation of quadriceps strength is the isokinetic dynamometer (ID) [ 16 , 17 ], which is beyond the affordability of most clinicians. Although more reasonable alternatives to the ID exists, such as a handheld dynamometer (HHD) [ 17 ], the reliability of an HHD depends on the strength and aptitude of the practitioner [ 18 , 19 ].…”