Reliability of Quadriceps Femoris Muscle Strength Assessment Using a Portable Dynamometer and Protocol Tolerance in Patients With Chronic Obstructive Pulmonary Disease.

OBJECTIVE: This study aimed to evaluate the intrarater and interrater reliability of isometric quadriceps strength (IQS) using a portable dynamometer in individuals with chronic obstructive pulmonary disease (COPD) and to verify their tolerance to the protocol. METHODS: A cross-sectional reliability study was conducted with 50 individuals with stable COPD (34 men and 16 women; mean age = 70 years [SD = 8]). The main outcome measure was obtained using a portable dynamometer (Microfet 2) to assess IQS. Two masked raters performed 2 assessments in the dominant lower limb on 2 nonconsecutive days. The intraclass correlation coefficient (ICC) was used to verify the intrarater and interrater reliability and was considered excellent when >0.90, with a 5% significance level. RESULTS: Rater 1 and 2 intrarater reliability was as follows: ICC = 0.96 (95% CI = 0.94 to 0.98) and ICC = 0.97 (95% CI = 0.95 to 0.98), respectively. The interrater reliability was as follows: ICC = 0.96 (95% CI = 0.93 to 0.98). The minimum detectable difference was 4 to 5 peak isometric strength, in mean, for intrarater and interrater reliability. Not all patients presented relevant changes in physiological responses, dyspnea, and lower limb fatigue. CONCLUSION: There was an excellent intrarater and interrater reliability for IQS, and the participants tolerated the protocol. IMPACT: This tool can be used to assess quadriceps strength in clinical practice in patients with COPD.

The concurrent validity and intrarater reliability of a hand-held dynamometer for the assessment of neck strength in semi-professional rugby union players.

OBJECTIVES: The main objective of this study was to determine the concurrent validity between a hand-held (HHD) and mounted hand-held dynamometer (MHHD) for assessing isometric neck strength. DESIGN: Observational design. SETTING: Semiprofessional rugby club. PARTICIPANTS: Nineteen semi-professional rugby players (age = 26 ± 5 years, stature = 186.5 ± 6.5 cm, body mass = 98.7 ± 12.8 kg). MAIN OUTCOME MEASURES: Concurrent validity (limits of agreement, correlation) between HHD and MHHD, the intrarater reliability (intra-class correlation, ICC) and comparison between playing positions. RESULTS: Absolute peak and mean peak force were systematically lower when using the HHD compared to MHHD, with the mean bias ranging from -1.8 to -3.8 kgf (P < 0.05). Differences were not evident for flexion when applying the correction equations (-0.5 to 2.1 kgf, P > 0.05) but remained for extension. Correlations between methods were large-to-very large; the ICCs for both methods were good (ICC = 0.72-0.89), with no difference between positions (P < 0.05). CONCLUSION: The concurrent validity of HHD was considered acceptable when compared to the MHHD and the correction equation applied. Both methods are reliable and useful for assessing neck strength in rugby players, though, caution is needed when determining strength during neck extension.

Concurrent Validity and Reliability of a Low-Cost Dynamometer to Assess Maximal Isometric Strength in Neck Movements.

OBJECTIVE: This study aimed to evaluate the concurrent validity and reliability of a low-cost digital dynamometer to assess maximal isometric strength in neck movements. METHODS: Twelve recreationally active participants (6 women, 6 men; age: 24.1 ± 3.4 years; height: 1.71 ± 0.06 m; weight: 64.6 ± 11.7 kg) performed neck flexion, extension, and lateral flexion, and maximal isometric strength was simultaneously measured using an isokinetic dynamometer (gold standard) and a digital dynamometer to evaluate the concurrent validity of the latter. One week later, all the participants repeated 3 trials of each neck movement (3 minutes apart) registered only with the digital dynamometer. The first and second trial were guided by tester 1 and the third trial was guided by tester 2. RESULTS: The concurrent validity of the digital dynamometer showed a nearly perfect correlation between both devices (r > 0.986, P < .001), with Bland-Altman plots showing absolute agreement. Intertester and intratester reliability were nearly perfect for all neck movements (intraclass correlation coefficient > 0.86). CONCLUSION: The low-cost digital dynamometer showed valid and reliable measurements of maximal isometric strength in neck movements.

Measurement Properties of Isokinetic Dynamometry for Assessment of Shoulder Muscle Strength: A Systematic Review.

OBJECTIVE: To investigate the evidence of measurement properties of isokinetic dynamometry (ID) for assessment of shoulder muscle strength in healthy individuals and patients with nonneurologic shoulder pathology. DATA SOURCES: Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Physiotherapy Evidence Database were searched up to February 2020 without restrictions. Reference lists and citations were hand-searched. STUDY SELECTION: Two review authors independently included studies that met the following criteria: (1) evaluated measurement properties of ID when used on the glenohumeral joint and (2) included individuals 18 years and older. Studies including patients with neurologic, neuromuscular, or systemic diseases or critical illness were excluded. DATA EXTRACTION: The quality assessment and data synthesis were performed according to the COnsensus-based Standards for the selection of health Measurement INstruments methodology. DATA SYNTHESIS: Twenty-one studies with a total of 597 participants were included. The results were combined separately for isometric, concentric, and eccentric test mode; for the velocities 30°/s-60°/s, 90°/s, 120°/s, and 240°/s; for the seated, supine, and standing position; and for internal rotation (IR), external rotation (ER), and the ER/IR ratio. The reliability of ID was overall sufficient with the majority of intraclass correlation coefficients ≥0.70. The quality of evidence was moderate or low for 20 of 30 strata examined. The measurement error results were rated as insufficient for all strata. The SEM ranged from 4%-28%. The quality of evidence varied depending of strata examined. CONCLUSIONS: The reliability of ID for measurement of shoulder strength was overall sufficient for all positions, velocities, and modes of strength. The measurement error was not sufficient. Because most studies used the seated position, the velocities 30°/s-60°/s or 120°/s, and the concentric test mode, the quality of evidence was highest for these conditions.

Validity of an Inexpensive Hanging Scale During Isometric Shoulder Movements.

CONTEXT: Strength assessment is essential to prescribe exercise in sports and rehabilitation. Low-cost valid equipment may allow continuous monitoring of training. OBJECTIVE: To examine the validity of a very low-cost hanging scale by comparing differences in the measures of peak force to a laboratory grade load cell during shoulder abduction, flexion, extension, and internal and external rotations. DESIGN: Analytical study. PARTICIPANTS: Thirty-two healthy subjects (18 women, age 26 [10] y, height 172 [8] cm, mass 69 [13] kg, body mass index 23 [4] kg/m2). MAIN OUTCOME MEASURES: The dependent variable was the maximal peak force (in kilogram-force). The independent variable was the instrument (laboratory grade load cell and hanging scale). RESULTS: No differences were observed while comparing the results. The intraclass correlation coefficients1,1 ranged from .96 to .99, showing excellent results. The Cronbach alpha test also returned >.99 for all comparisons. The SEM ranged from 0.02 to 0.04 kgf, with an averaged SD from 0.24 to 0.38 kgf. The correlation was classified as high for all tested movements (r > .99; P < .001), with excellent adjusted coefficients of determination (.96 < r2 < .99). Bland-Altman results showed high levels of agreement with bias ranging from 0.27 to 0.48. CONCLUSIONS: Hanging scale provides valid measures of isometric strength with similar output measures as laboratory grade load cell.

Measurement properties of handheld dynamometry for assessment of shoulder muscle strength: A systematic review.

Like any assessment tool, handheld dynamometry (HHD) must be valid and reliable in order to be meaningful in clinical practice and research. To summarize the evidence of measurement properties of HHD for the assessment of shoulder muscle strength. Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, and PEDro were searched up to February 2020. Inclusion criteria were studies (a) evaluating HHD used on the glenohumeral joint, (b) evaluating measurement properties, and (c) included individuals ≥ 18 years old with or without shoulder symptoms. Exclusion criteria were studies (a) including patients with neurologic, neuromuscular, systemic diseases, or critical illness or bed-side patients and (b) that did not report the results separately for each movement. In total, 28 studies with 963 participants were included. The reliability results showed that 98% of the intraclass correlation coefficient (ICC) values were ≥0.70. The measurement error showed that the minimal detectable change in percent varied from 0% to 51.0%. The quality of evidence was high or moderate for the majority of movements and type of reliability examined. Based on the evidence of low or very low quality of evidence, the convergent validity and discriminative validity of HHD were either sufficient, indeterminate, or insufficient. The reliability of HHD was overall sufficient, and HHD can be used to distinguish between individuals on the group level. The measurement error was not sufficient, and evaluation of treatment effect on the individual level should be interpreted with caution.

Reliability of Ankle⁻Foot Complex Isokinetic Strength Assessment Using the Isomed 2000 Dynamometer.

For quantifying muscle strength in clinical and research practice, establishing the reliability of measurements, specifically to the procedures used, is essential for credible findings. The objective was to establish the reliability of isokinetic measurement of ankle plantar and dorsal flexors (PF/DF) and invertors and evertors (INV/EV) on an IsoMed 2000 dynamometer. Twenty healthy subjects (10 males, 10 females, mean age: 23.1 ± 3.1 years) completed an isokinetic measurement session. The intraclass correlation coefficient (ICC) and standard error of measurement were assessed for peak torque and work of ankle PF/DF (concentric and eccentric) and INV/EV (concentric) for the preferred and nonpreferred limb. Standardized isokinetic measurements of reciprocal PF/DF and INV/EV muscle actions were associated with ICC ranging from 0.77 to 0.98 for the majority of observed parameters. The exception was work in the eccentric mode in the ankle DF and peak torque in the concentric mode in the ankle INV on the preferred limb, where ICC ranged from 0.64 to 0.71. The IsoMed 2000 isokinetic dynamometer can be reliably employed in future studies for reciprocal ankle PF/DF and INV/EV assessment in healthy adult subjects after implementation of a familiarization session.

Muscle Strength and Poststroke Hemiplegia: A Systematic Review of Muscle Strength Assessment and Muscle Strength Impairment.

OBJECTIVES: To systematically review (1) psychometric properties of criterion isokinetic dynamometry testing of muscle strength in persons with poststroke hemiplegia (PPSH); and (2) literature that compares muscle strength in patients poststroke with that in healthy controls assessed by criterion isokinetic dynamometry. DATA SOURCES: A systematic literature search of 7 databases was performed. STUDY SELECTION: Included studies (1) enrolled participants with definite poststroke hemiplegia according to defined criteria; (2) assessed muscle strength or power by criterion isokinetic dynamometry; (3) had undergone peer review; and (4) were available in English or Danish. DATA EXTRACTION: The psychometric properties of isokinetic dynamometry were reviewed with respect to reliability, validity, and responsiveness. Furthermore, comparisons of strength between paretic, nonparetic, and comparable healthy muscles were reviewed. DATA SYNTHESIS: Twenty studies covering 316 PPSH were included. High intraclass correlation coefficient (ICC) inter- and intrasession reliability was reported for isokinetic dynamometry, which was independent of the tested muscle group, contraction mode, and contraction velocity. Slightly higher ICC values were found for the nonparetic extremity. Standard error of the mean (SEM) values showed that a change of 7% to 20% was required for a real group change to take place for most muscle groups, with the knee extensors showing the smallest SEM% values. The muscle strength of paretic muscles showed deficits when compared with both healthy and nonparetic muscles, independent of muscle group, contraction mode, and contraction velocity. Nonparetic muscles only showed minor strength impairments when compared with healthy muscles. CONCLUSIONS: Criterion isokinetic dynamometry is a reliable test in persons with stroke, generally showing marked reductions in muscle strength of paretic and, to a lesser degree, nonparetic muscles when compared with healthy controls, independent of muscle group, contraction mode, and contraction velocity.

Objective assessment of shoulder mobility with a new 3D gyroscope--a validation study.

BACKGROUND: Assessment of shoulder mobility is essential for clinical follow-up of shoulder treatment. Only a few high sophisticated instruments for objective measurements of shoulder mobility are available. The interobserver dependency of conventional goniometer measurements is high. In the 1990s an isokinetic measuring system of BIODEX Inc. was introduced, which is a very complex but valid instrument. Since 2008 a new user-friendly system called DynaPort MiniMod TriGyro ShoulderTest-System (DP) is available. Aim of this study is the validation of this measuring instrument using the BIODEX-System. METHODS: The BIODEX is a computerized robotic dynamometer used for isokinetic testing and training of athletes. Because of its size the system needs to be installed in a separated room. The DP is a small, light-weighted three-dimensional gyroscope that is fixed on the distal upper patient arm, recording abduction, flexion and rotation. For direct comparison we fixed the DP on the lever arm of the BIODEX. The accuracy of measurement was determined at different positions, angles and distances from the centre of rotation (COR) as well as different velocities in a radius between 0° - 180° in steps of 20°. All measurements were repeated 10 times. As satisfactory accuracy a difference between both systems below 5° was defined. The statistical analysis was performed with a linear regression model. RESULTS: The evaluation shows very high accuracy of measurements. The maximum average deviation is below 2.1°. For a small range of motion the DP is slightly underestimating comparing the BIODEX, whereas for higher angles increasing positive differences are observed. The distance to the COR as well as the position of the DP on the lever arm have no significant influence. Concerning different motion speeds significant but not relevant influence is detected. Unfortunately device related effects are observed, leading to differences between repeated measurements with any two different devices up to 8° at maximal range of motion (180°). CONCLUSIONS: In summary the results shows high correlation and good reproducibility of measurements. All deviations are inside the tolerance interval of 5°, if one device is used. An unlikely systematic device effect is detected. These laboratory trials are promising for the validation of this system in humans. The challenge for both systems will be the changing of the COR in the shoulder joint at elevations higher than 90°.

Reliability of handheld dynamometry in assessment of hip strength in adult male football players.

The aim of this study was to evaluate the intra- and interrater reliability of handheld dynamometry (HHD) for measuring hip muscle strength in a sample of 30 healthy semi-professional adult male football players. The reliability of HHD had not been assessed in athletes who were likely to be stronger than populations tested previously. Maximal isometric strength of resisted hip flexion and adduction were measured. Mean strength ranged from 51.5 kg for dominant hip flexion to 26.7 kg for hip adduction at 90 degrees of hip flexion. Intrarater reliability intraclass correlation coefficients (ICCs) ranged from 0.70 to 0.89. ICCs for interrater reliability ranged from 0.66 to 0.87. As expected, muscle strength in this group of athletes was significantly higher than that of populations in which HHD reliability has been assessed. Despite this, muscle strength testing of hip flexor and adductor muscles can be performed with good to excellent intra- and interrater reliability in this population.