Reliability of measurements of wrist extension force obtained with a Nicholas Manual Muscle Tester (NMMT)

Validity and reliability of the DiCI for the measurement of shoulder flexion and abduction strength in asymptomatic and symptomatic subjects

Background

A higher risk of shoulder injury in the athletic and non-athletic population is frequently associated with strength deficits. Therefore, shoulder strength assessment can be clinically useful to identify and to quantify the magnitude of strength deficit. Thus, the aim of this study was to evaluate the validity and reliability of a DiCI (a new hand-held dynamometer) for the measurement of shoulder flexion and abduction strength in asymptomatic and symptomatic subjects.

Methods

Forty-three recreational athletes (29 males and 14 females; age: 22.1 ± 0.47 years; body mass: 68.7 ± 13.1 kg; height = 173.3 ± 9.7 cm) and 40 symptomatic subjects (28 males and 12 females; age: 49.9 ± 8.1 years; body mass: 70.6 ± 14.3 kg; height = 171.7 ± 9.0 cm) completed shoulder flexion and abduction strength tests in two identical sessions one-week apart. Both types of movement were evaluated at 45º and 90º.

Results

Relative reliability analysis showed excellent intra-class correlation coefficients (ICC) for all evaluated movements (ICC range = 0.90 to 0.99). Absolute reliability analysis showed a standard error of measurement (SEM) ranging from 1.36% to 2.25%, and minimal detectable change (MDC) ranging from 3.93% to 6.25%. In conclusion, the DiCI is a valid and reliable device for assessing shoulder strength both in recreational athletes and in subjects with restricted mobility and loss of strength.

Hand-held dynamometry for assessment of muscle strength in patients with inflammatory myopathies

OBJECTIVES

Muscle weakness in idiopathic inflammatory myopathies (IIMs) is conventionally assessed using manual muscle testing (MMT). However, more objective tools must be developed to accurately and reliably quantify muscle strength in myositis patients. Hand-held dynamometry (HHD) is a quantitative, portable device with reported reliability in neuromuscular disorders. Our aim was to assess the reliability, validity and responsiveness of HHD in myositis.

METHODS

Myositis patients [DM, necrotizing myopathy (NM), PM and anti-synthetase syndrome] evaluated at the University of Pittsburgh myositis centre were prospectively enrolled. Each patient was assessed at 0, 3 and 6 months for validated outcome measures of myositis disease activity and physical function. At each visit, muscle strength was assessed using both MMT and HHD (Micro FET2, Hoggan Health Industries, Draper, UT, USA). The reliability, validity and responsiveness of the HHD was assessed using standard statistical methods.

RESULTS

Fifty IIM patients (60% female; mean age 51.6 years; 6 PM, 9 NM, 24 DM and 11 anti-synthetase syndrome) were enrolled. HHD showed strong test-retest intrarater reliability (r = 0.96) and interrater reliability (r = 0.98). HHD correlated significantly with the MMT score (r = 0.48, P = 0.0006) and myositis disease activity and functional measures. Longitudinal analysis showed a significant and strong association between the HHD and MMT as well as 2016 ACR/EULAR myositis response criteria (r = 0.8, P < 0.0001) demonstrating responsiveness. The mean effect size and standardized response mean of HHD was large: 0.95 and 1.03, respectively. MMT had a high ceiling effect compared with HHD.

CONCLUSION

HHD demonstrated strong reliability, construct validity and responsiveness in myositis patients. External validation studies are required to confirm these findings.

Isometric Exercise Above but not Below an Individual's Pain Threshold Influences Pain Perception in People With Lateral Epicondylalgia

OBJECTIVE

To examine the acute effects of isometric exercise of different intensities on pain perception in individuals with chronic lateral epicondylalgia.

MATERIALS AND METHODS

Participants performed 3 experimental tasks completed in a randomized order on separate days: control (no exercise) and isometric wrist extension (10×15 s) at load 20% below (infrathreshold), and 20% above (suprathreshold) an individual's pain threshold. Self-reported pain intensity (11-point numeric rating scales), pressure pain threshold, and pain-free grip were assessed by a blinded examiner before, immediately after, and 30 minutes after task performance. Relation analysis between pain ratings and clinical variables, including pain and disability and kinesiophobia was performed.

RESULTS

Twenty-four individuals with unilateral lateral epicondylalgia of median 3-month duration participated. Pain intensity during contraction was significantly higher during suprathreshold exercise than infrathreshold exercise (mean difference in numeric rating scale 1.0; 95% confidence interval, 0.4-1.5; P=0.002). Pain intensity during suprathreshold exercise was significantly correlated with pain and disability (R=0.435, P=0.034) and kinesiophobia (R=0.556, P=0.005). Pain intensity was significantly higher immediately after performance of suprathreshold exercise, compared with infrathreshold exercise (P=0.01) and control (P<0.001) conditions, whereas infrathreshold exercise and control conditions were comparable. Thirty minutes later, pain levels remained significantly higher for suprathreshold exercise compared with infrathreshold exercise (P=0.043). Pressure pain threshold and pain-free grip showed no significant effects of time, condition, or time×condition (P>0.05).

DISCUSSION

Individuals with lateral epicondylalgia demonstrated increased pain intensity after an acute bout of isometric exercise performed at an intensity above, but not below, their individual pain threshold. Further investigation is needed to determine whether measurement of an individual's exercise induced pain threshold may be important in reducing symptom flares associated with exercise.

Upper limb strength: study providing normative data for a clinical handheld dynamometer

OBJECTIVE

To establish normative clinical data for upper extremity strength of men and women, ages 20-64 years, using a portable clinical device, the Nicholas Manual Muscle Tester (NMMT).

DESIGN

The study collected objective upper extremity strength data for 180 healthy men and women using the NMMT.

SETTING

The study was conducted in outpatient and community settings.

SUBJECTS

One hundred eighty normal volunteers (90 men and 90 women).

METHODS

Eleven upper extremity muscle groups were tested using standardized methodology.

MAIN OUTCOME MEASUREMENTS

Data were recorded for each muscle group in each subject.

RESULTS

This study presents data from 180 healthy, normal subjects, equally divided by gender and age. Means ± standard deviations were determined for each group and further categorized by age, gender, and hand dominance. These data confirm some expected patterns: In all the muscle groups men have significantly higher strength than women, and the dominant side is stronger than the nondominant side in men and women. Relative values for various muscle groups are analyzed and presented.

CONCLUSIONS

This study provides an initial normative database across a wide age range in men and women for upper extremity strength for monitoring clinical care and research for injured and impaired patients. These data are an essential and initial step toward comprehensive normative databases for upper extremity objective ordinal strength measurements with the NMMT.

Intraexaminer reliability of hand-held dynamometry in the upper extremity: a systematic review

OBJECTIVE

To summarize and appraise the literature on the intraexaminer reliability of hand-held dynamometry (HHD) in the upper extremity.

DATA SOURCES

MEDLINE, CINAHL, and EMBASE were searched for relevant studies published up to December 2011. In addition, experts were contacted, and journals and reference lists were hand searched.

STUDY SELECTION

To be included in the review, articles needed to (1) use a repeated-measures, within-examiner(s) design; (2) include symptomatic or asymptomatic individuals, or both; (3) use HHD to measure muscle strength in any of the joints of the shoulder, elbow, or wrist with the "make" or the "break" technique; (4) report measurements in kilogram, pound, or torque; (5) use a device that is placed between the examiner's hand and the subject's body; and (6) present estimates of intraexaminer reliability.

DATA EXTRACTION

Quality assessment and data extraction were performed by 2 reviewers independently.

DATA SYNTHESIS

Fifty-four studies were included, of which 26 (48%) demonstrated acceptable intraexaminer reliability. Seven high-quality studies showed acceptable reliability for flexion and extension of the elbow in healthy subjects. Conflicting results were found for shoulder external rotation and abduction. Reliability for all other movements was unacceptable. Higher estimates were reached for within-sessions reliability and if means of trials were used.

CONCLUSIONS

Intraexaminer reliability of HHD in upper extremity muscle strength was acceptable only for elbow measurements in healthy subjects. We provide specific recommendations for future research. Physical therapists should not rely on HHD measurements for evaluation of treatment effects in patients with upper extremity disorders.