Rotterdam Intrinsic Hand Myometer Research Articles

Test–retest Reliability and Precision of the Rotterdam Intrinsic Hand Myometer

The purpose of this study was to determine the test-retest reliability and precision of Rotterdam Intrinsic Hand Myometer (RIHM) in healthy adults. Twenty-nine participants originally recruited via convenience sampling at a Midwestern state fair returned approximately 8 days later for retest. An average of three trials for each of the five intrinsic hand strength measurements were collected using the same technique that was used during initial testing. Test-retest reliability was assessed using the intraclass correlation coefficient or ICC(2,3) and precision was evaluated using the standard error of measurement (SEM), and the minimal detectable change (MDC90)/MDC%. Across all measures of intrinsic strength, the RIHM and its standardized procedures had excellent test-retest reliability. Index finger metacarpophalangeal flexion demonstrated the lowest reliability, and right small finger abduction, left thumb carpometacarpal abduction, and index finger metacarpophalangeal abduction tests had the highest reliability. Precision, as evidenced by SEM and MDC values, was excellent for tests of left index and bilateral small finger abduction strength and acceptable for all other measurements. Test-retest reliability and precision of RIHM across all measurements was excellent. These findings indicate that RIHM is a reliable and precise tool in measuring intrinsic strength of hands of healthy adults, although further research is needed in clinical populations.

Age- and gender-stratified adult myometric reference values of isometric intrinsic hand strength

Study DesignDescriptive normative. IntroductionIntrinsic hand strength can be impacted by hand arthritis, peripheral nerve injuries, and spinal cord injuries. Grip dynamometry does not isolate intrinsic strength, and manual muscle testing is not sensitive to change in grades 4 and 5. The Rotterdam Intrinsic Hand Myometer is a reliable and valid test of intrinsic hand strength; however, no adult normative data are available. Purpose of the StudyTo describe age- and gender-stratified intrinsic hand strength norms in subjects aged 21 years and above and to determine if factors known to predict grip dynamometry also predict measures of intrinsic hand strength. MethodsThree trials of 5 measures of maximal isometric intrinsic strength were performed bilaterally by 607 “healthy-handed” adult males and females. Average strength values were stratified by age and gender. Data were analyzed to determine the influence of demographic and anthropometric variables on intrinsic strength. ResultsIntrinsic strength generally followed age and gender trends similar to grip dynamometry. Age, gender, body mass index, and the interaction between gender and body mass index were predictors of intrinsic strength, whereas in most cases, the hand being tested did not predict the intrinsic strength. DiscussionWith the addition of these findings, age- and gender-stratified hand intrinsic strength norms now span from age 4 through late adulthood. Many factors known to predict grip dynamometry also predict intrinsic myometry. Additional research is needed to evaluate the impact of vocational and avocational demands on intrinsic strength. ConclusionsThese norms can be referenced to evaluate and plan hand therapy and surgical interventions for intrinsic weakness.

Functional, motor, and sensory assessment instruments upon nerve repair in adult hands: systematic review of psychometric properties

BackgroundOutcome after nerve repair of the hand needs standardized psychometrically robust measures. We aimed to systematically review the psychometric properties of available functional, motor, and sensory assessment instruments after nerve repair.MethodsThis systematic review of health measurement instruments searched databases from 1966 to 2017. Pairs of raters conducted data extraction and quality assessment using a structured tool for clinical measurement studies. Kappa correlation was used to define the agreement prior to consensus for individual items, and intraclass correlation coefficient (ICC) was used to assess reliability between raters. A narrative synthesis described quality and content of the evidence.ResultsSixteen studies were included for final critical appraisal scores. Kappa ranged from 0.31 to 0.82 and ICC was 0.81. Motor domain had manual muscle testing with Kappa from 0.72 to 0.93 and a dynamometer ICC reliability between 0.92 and 0.98. Sensory domain had touch threshold Semmes-Weinstein monofilaments (SWM) as the most responsive measure while two-point discrimination (2PD) was the least responsive (effect size 1.2 and 0.1). A stereognosis test, Shape and Texture Identification (STI), had Kappa test-retest reliability of 0.79 and inter-rater reliability of 0.61, with excellent sensibility and specificity. Manual tactile test had moderate to mild correlation with 2PD and SWM. Function domain presented Rosén-Lundborg score with Spearman correlations of 0.83 for total score. Patient-reported outcomes measurements had ICC of 0.85 and internal consistency from 0.88 to 0.96 with Patient-Rated Wrist and Hand Evaluation with higher score for reliability and Spearman correlation between 0.38 and 0.89 for validity.ConclusionsFew studies included nerve repair in their sample for the psychometric analysis of outcome measures, so moderate evidence could be confirmed. Manual muscle test and Rotterdam Intrinsic Hand Myometer dynamometer had excellent reliability but insufficient data on validity or responsiveness. Touch threshold testing was more responsive than 2PD test. The locognosia test and STI had limited but positive supporting data related to validity. Rosén-Lundborg score had emerging evidence of reliability and validity as a comprehensive outcome following nerve repair. Few questionnaires were considered reliable and valid to assess cold intolerance. There is no patient-reported outcome measurement following nerve repair that provides comprehensive assessment of symptoms and function by patient perspective.

New Device for Intrinsic Hand Muscle Strength Measurement: An Alternative to Strain Gauge Handheld Dynamometer.

An accurate measurement of intrinsic hand muscle strength (IHMS) is required by clinicians for effective clinical decision-making, diagnosis of certain diseases, and evaluation of the outcome of treatment. In practice, the clinicians use Intrins-o-meter and Rotterdam Intrinsic Hand Myometer for IHMS measurement. These are quite bulky, expensive, and possess poor interobserver reliability (37-52%) and sensitivity. The purpose of this study was to develop an alternative lightweight, accurate, cost-effective force measurement device with a simple electronic circuit and test its suitability for IHMS measurement. The device was constructed with ketjenblack/deproteinized natural rubber sensor, 1-MΩ potential divider, and Arduino Uno through the custom-written software. Then, the device was calibrated and tested for accuracy and repeatability within the force range of finger muscles (100 N). The 95% limit of agreement in accuracy from -1.95 N to 2.06 N for 10 to 100 N applied load and repeatability coefficient of ±1.91 N or 6.2% was achieved. Furthermore, the expenditure for the device construction was around US$ 53. For a practical demonstration, the device was tested among 16 participants for isometric strength measurement of the ulnar abductor and dorsal interossei. The results revealed that the performance of the device was suitable for IHMS measurement.

Reference values of intrinsic muscle strength of the hand of adolescents and young adults

Study DesignA cross-sectional clinical measurement study. IntroductionMeasuring intrinsic hand muscle strength helps evaluate hand function or therapeutic outcomes. However, there are no established normative values in adolescents and young adults between 13 and 20 years of age. Purpose of the StudyTo measure hand intrinsic muscle strength and identify associated factors that may influence such in adolescents and young adults through use of the Rotterdam intrinsic hand myometer. MethodsA total of 131 participants (male: 63; female: 68) between 13 and 20 years of age completed the strength measurements of abductor pollicis brevis, first dorsal interosseus (FDI), deep head of FDI and lumbrical of second digit, flexor pollicis brevis (FPB), and abductor digiti minimi. Two trials of the measurements of each muscle were averaged for analyses. Self-reported demographic data were used to examine the influences of age, sex, and body mass index (BMI) on intrinsic hand muscle strength. ResultsNormative values of intrinsic hand muscle strength were presented by age groups (13, 14, 15-16, 17-18, 19-20 year olds) for each sex category (male, female). A main effect of sex, but not age, on all the muscles on both the dominant (FPB: P = .02, others: P < .001) and non-dominant (FDI: P = .005, FPB: P = .01, others: P < .001) sides was found. A significant effect of BMI was found on dominant (P = .009) and non-dominant abductor pollicis brevis (P = .002). In addition, FDI (P = .005) and FPB (P = .002) were stronger on the dominant side than the non-dominant side. DiscussionIntrinsic hand muscle strength may be influenced by different factors including sex, BMI, and hand dominance. A larger sample is needed to rigorously investigate the influence of age on intrinsic strength in male and female adolescents and young adults. ConclusionThe results provide reference values and suggest factors to be considered when evaluating hand function and therapeutic outcomes in both clinical and research settings. Further study is recommended. Level of EvidenceVI.

Measuring intrinsic hand strength in healthy adults: The accuracy intrarater and inter-rater reliability of the Rotterdam Intrinsic Hand Myometer

Study DesignClinical measurement study. IntroductionMeasuring the isometric strength generated during isolated hand joint motions is a challenging feat. The Rotterdam Intrinsic Hand Myometer (RIHM; med.engineers, Rotterdam, Netherlands) permits measurement of isolated movements of the hand. To date, there is limited evidence on the inter-rater reliability and limited adult normative data of RIHM. Given that multiple raters, often with varying degrees of experience, are needed to collect normative data, inter-rater reliability testing and a comparison of novice and experienced raters are needed. Purposes of the StudyThe purposes of this study were to test the accuracy, intrarater reliability, and inter-rater reliability of the RIHM in healthy-handed adults. MethodsRIHM accuracy was tested through use of precision class F weights. Adults 18 years or older without upper limb dysfunction were recruited. Each participant was tested by 4 raters, 3 occupational therapy graduate students, and an experienced certified hand therapist, through use of a calibrated RIHM. Five strength measures were tested bilaterally (ie, thumb carpometacarpal palmar abduction, index finger metacarpophalangeal [MP] abduction, index finger MP flexion, thumb MP flexion, and small finger MP abduction) 3 times per a standardized protocol. Statistical methods were used to test accuracy, inter-rater reliability, and intrarater/response stability. ResultsThe accuracy of RIHM device error was 5% or less. Reliability testing included the participation of 19 women and 10 men (n = 29). All raters were in excellent agreement across all muscles (intraclass correlation coefficient, ≥0.81). Low standard error of measurement values of ≤8.3 N (1.9 lb) across raters were found. The response stability and/or intrarater reliability of the novice and certified hand therapist raters were not statistically different. DiscussionThe RIHM has an acceptable instrument error; the RIHM and its standardized procedure have excellent inter-rater reliability and response stability when testing those without hand limitations; and the response stability and/or intrarater reliability of expert and novice raters were consistent. ConclusionsThe use of the RIHM is justified when multiple raters of varying expertise collect normative data or conduct cohort studies on persons with healthy hands. Future research is warranted. Level of EvidenceNot applicable.

Ultrasonographic Quantification of Intrinsic Hand Muscle Cross-Sectional Area; Reliability and Validity for Predicting Muscle Strength

ObjectiveTo investigate whether ultrasonographic measurement of the cross-sectional area (CSA) of the intrinsic hand muscles can be used to predict muscle strength in a valid and reliable manner, and to determine if this method can be used for follow-up of patients with peripheral nerve injury between the wrist and elbow. DesignRepeated-measures cross-sectional study. SettingClinical and academic hospital. ParticipantsHealthy adults (n=31) and patients with ulnar and median nerve injuries (n=16) between the wrist and elbow who were visiting the Erasmus Medical Center or Maasstad Hospital were included in the study (N=47). InterventionsNot applicable. Main Outcome MeasuresCorrelation between measured muscle CSA and strength and assessment of inter- and intrarater reliability. Ultrasound and strength measurements of the intrinsic hand muscles were conducted bilaterally. To establish validity, the CSA of 4 muscles (abductor digiti minimi, first dorsal interosseus, abductor pollicis brevis, opponens pollicis) was compared with strength measurements of the same muscles conducted with the Rotterdam Intrinsic Hand Myometer. Repeated measures were conducted to assess inter- and intrarater reliability. ResultsThe assessed CSA strongly correlated with strength measurements, with correlations ranging from 0.82 to 0.93 in healthy volunteers and from 0.63 to 0.94 in patients. Test-retest reliability showed excellent intrarater reliability (intraclass correlation coefficient range, 0.99–1.00) in patients and volunteers and good interrater reliability (intraclass correlation coefficient range, 0.88–0.95) in healthy volunteers. ConclusionsWe found that ultrasound is a valid and reliable method to assess the CSA of specific muscles in the hand. Therefore, this technique could be useful to monitor muscle reinnervation in patients suffering from peripheral nerve injury as a valuable addition to strength dynamometers.

The added value of measuring thumb and finger strength when comparing strength measurements in hypoplastic thumb patients

BackgroundWhen interventions to the hand are aimed at improving function of specific fingers or the thumb, the RIHM (Rotterdam Intrinsic Hand Myometer) is a validated tool and offers more detailed information to assess strength of the involved joints besides grip and pinch measurements. MethodsIn this study, strength was measured in 65 thumbs in 40 patients diagnosed with thumb hypoplasia. These 65 thumbs were classified according to Blauth. Longitudinal radial deficiencies were also classified. The strength measurements comprised of grip, tip, tripod and key pinch. Furthermore palmar abduction and opposition of the thumb as well as abduction of the index and little finger were measured with the RIHM. FindingsFor all longitudinal radial deficiency patients, grip and pinch strength as well as palmar abduction and thumb opposition were significantly lower than reference values (P<0.001). However, strength in the index finger abduction and the little finger abduction was maintained or decreased to a lesser extent according to the degree of longitudinal radial deficiency. All strength values decreased with increasing Blauth-type. Blauth-type II hands (n=15) with flexor digitorum superficialis 4 opposition transfer including stabilization of the metacarpophalangeal joint showed a trend toward a higher opposition strength without reaching statistical significance (P=0.094),however compared to non-operated Blauth-type II hands (n=6) they showed a lower grip strength (P=0.019). InterpretationThe RIHM is comparable in accuracy to other strength dynamometers. Using the RIHM, we were able to illustrate strength patterns on finger-specific level, showing added value when evaluating outcome in patients with hand related problems.

Outcome following nerve repair of high isolated clean sharp injuries of the ulnar nerve.

ObjectiveThe detailed outcome of surgical repair of high isolated clean sharp (HICS) ulnar nerve lesions has become relevant in view of the recent development of distal nerve transfer. Our goal was to determine the outcome of HICS ulnar nerve repair in order to create a basis for the optimal management of these lesions.MethodsHigh ulnar nerve lesions are defined as localized in the area ranging from the proximal forearm to the axilla just distal to the branching of the medial cord of the brachial plexus. A meta-analysis of the literature concerning high ulnar nerve injuries was performed. Additionally, a retrospective study of the outcome of nerve repair of HICS ulnar nerve injuries at our institution was performed. The Rotterdam Intrinsic Hand Myometer and the Rosén-Lundborg protocol were used.ResultsThe literature review identified 46 papers. Many articles presented outcomes of mixed lesion groups consisting of combined ulnar and median nerves, or the outcome of high and low level injuries was pooled. In addition, outcome was expressed using different scoring systems. 40 patients with HICS ulnar nerve lesions were found with sufficient data for further analysis. In our institution, 15 patients had nerve repair with a median interval between trauma and reconstruction of 17 days (range 0–516). The mean score of the motor and sensory domain of the Rosen's Scale instrument was 58% and 38% of the unaffected arm, respectively. Two-point discrimination never reached less then 12 mm.ConclusionFrom the literature, it was not possible to draw a definitive conclusion on outcome of surgical repair of HICS ulnar nerve lesions. Detailed neurological function assessment of our own patients showed that some ulnar nerve function returned. Intrinsic muscle strength recovery was generally poor. Based on this study, one might cautiously argue that repair strategies of HICS ulnar nerve lesions need to be improved.

A COMPARISON OF THE STRENGTH OF THE ABDUCTION OF THE LITTLE AND INDEX FINGERS AND PALMAR ABDUCTION AND OPPOSITION OF THE THUMB BETWEEN COLLEGE BASEBALL PLAYERS AND INEXPERIENCED SPORTS PLAYERS

The purpose of this study was to investigate the strengths of four intrinsic muscles of the hand of college baseball players. The strengths of four intrinsic muscle groups were measured by the Rotterdam Intrinsic Hand Myometer (RIHM) which has been developed to assess the abduction of the little finger and index finger, and palmar abduction and opposition of the thumb. The strengths of these four intrinsic muscle groups were compared between baseball players and inexperienced sports players. The abduction of the little finger and index finger, and the opposition of the thumb in both the dominant and nondominant hands of the baseball players were notably stronger than those of the inexperienced sports players. There was no statistical difference in the strength of the palmar abduction of the thumb between the two groups. The results suggest that the specific intrinsic muscles in both the dominant and nondominant hands might be strengthened by repeated baseball practices, such as a batting performance, which requires strain in both the dominant and nondominant hands repeatedly.

The hypothesis of overwork weakness in Charcot-Marie-Tooth: A critical evaluation

It has been reported that the non-dominant hand of patients with Charcot-Marie-Tooth disease is stronger than the dominant hand as a result of overwork weakness. The objective of this study was to determine if this hypothesis could be verified in our population. Survey. Twenty-eight patients with Charcot-Marie-Tooth disease type I or II from a rehabilitation department of a university hospital in the Netherlands. The strength of 3 intrinsic muscle groups of the dominant and non-dominant hand were determined using the Medical Research Council scale and the Rotterdam Intrinsic Hand Myometer. Furthermore, grip strength, pinch and key grip strength were measured. We found no differences in muscle strength for the dominant and non-dominant hand, except for a stronger key grip strength of the dominant hand in patients with Charcot-Marie-Tooth disease type II. In our population, the dominant hand of patients with Charcot-Marie-Tooth disease type I and II was equally strong as the non-dominant hand, suggesting that there is no presence of overwork weakness in the dominant hand in our group of patients. This implies that patients with Charcot-Marie-Tooth disease do not have to limit the use of their hands in daily life in order to prevent muscle strength loss.

Reliability of Hand Strength Measurements Using the Rotterdam Intrinsic Hand Myometer in Children

Grip strength and pinch strength measurements are often used to assess hand function. However, both measure a number of muscle groups in combination, and grip strength in particular is dominated by extrinsic hand muscles. The Rotterdam Intrinsic Hand Myometer (RIHM) was recently introduced to measure the force that individual fingers and thumb can exert in different directions. The aim of this study was to establish the reliability of these measurements with use of the RIHM in children. Sixty-three healthy children between 4 and 12 years of age participated in this study. The RIHM was used to measure thumb palmar abduction, thumb opposition, thumb flexion at the metacarpal-phalangeal (MP) joint, index finger abduction, and little finger abduction. A retest was performed with an average test-retest interval of 26 days. For the thumb, palmar abduction strength had intraclass correlation coefficients (ICCs) of .98 for both hands. For both thumb opposition and flexion at the MP joint, ICCs were .97 for the dominant hands and .98 for the nondominant hands. Index finger abduction had ICCs of .94 and .95 and little finger abduction had ICCs of .90 and .92 for the dominant and nondominant hands, respectively. The smallest detectable differences for dominant and nondominant hands respectively were thumb palmar abduction, 15% and 15%; thumb opposition, 12% and 9%; thumb flexion (at the MP joint), 12% and 9%; abduction of the index finger, 17% and 17%; and little finger abduction, 26% and 26%. We found that the RIHM was reliable for use in children. Intraclass correlation coefficients and smallest detectable differences were comparable with those obtained with use of the RIHM in adults and with values found for pinch and grip strength in children. Because the RIHM measures more specific aspects of hand function than grip and pinch, adding the RIHM to measurement protocols may contribute to a more complete overview of a child's hand function.

Dynamometry of intrinsic hand muscles in patients with Charcot–Marie–Tooth disease

Several problems are associated with manual muscle testing and dynamometry in the hands of patients with Charcot-Marie-Tooth (CMT) disease. To evaluate the efficacy of the Rotterdam Intrinsic Hand Myometer (RIHM) to directly measure intrinsic hand muscle strength in CMT disease. We measured hand muscle strength and hand function in 41 patients with CMT disease. RIHM measurement of intrinsic strength had excellent reliability. We found overlapping RIHM strength values in Medical Research Council grades 3 to 5. High grip and pinch strength could be found in patients with severe intrinsic muscle weakness. RIHM measurements were more strongly correlated with fine motor skills of the hand than grip and pinch strength. The Rotterdam Intrinsic Hand Myometer is a reliable instrument to measure intrinsic hand muscles strength in patients with Charcot-Marie-Tooth disease, providing more detailed information than manual muscle testing and a more direct assessment of intrinsic muscle loss than grip and pinch dynamometers.

Strength Measurements of the Intrinsic Hand Muscles: A Review of the Development and Evaluation of the Rotterdam Intrinsic Hand Myometer

Numerous neurological diseases are accompanied by atrophy of the intrinsic muscles of the hand. Muscle strength testing of these muscles is frequently used for clinical decision making. Traditionally, these strength measurements have focused on manual muscle testing (MMT) or on grip and pinch strength dynamometry. We have developed a hand-held dynamometer, the Rotterdam Intrinsic Hand Myometer (RIHM), to measure this intrinsic muscle strength. The RIHM was designed such that it can measure a wide range of muscle groups, such as the abduction and adduction strength of the little finger and index finger, the opposition, palmar abduction (anteposition) and opposition strength of the thumb, and intrinsic muscles of the fingers combined in the intrinsic plus position. We found that the reliability of RIHM measurements in nerve injury patients was comparable to grip and pinch strength measurements and is appropriate to study the functional recovery of the intrinsic muscles of the hand in isolation. We have applied the RIHM in a recent study on the long-term outcome of muscle strength in patients with ulnar and median nerve injuries and found that while recovery of grip and pinch strength was relatively good, recovery of the ulnar nerve innervated muscles measured with the RIHM was poor. This poor recovery could not be detected with manual muscle strength testing or with grip and pinch dynamometry. We conclude that the RIHM provides an accurate clinical assessment of the muscle strength of the intrinsic hand muscles that adds valuable information to MMT and grip and pinch dynamometry.

Long-term outcome of muscle strength in ulnar and median nerve injury: comparing manual muscle strength testing, grip and pinch strength dynamometers and a new intrinsic muscle strength dynamometer

To compare the outcome of muscle strength with manual muscle strength testing grip and pinch strength measurements and a dynamometer which allows for measurements of the intrinsic muscles of the hand in isolation (the Rotterdam Intrinsic Hand Myometer, RIHM). Thirty-four patients more than 2 years after ulnar and/or median nerve injury. Muscle strength was evaluated using manual muscle strength testing (MMST), grip, pinch and intrinsic muscle strength measurements. Manual muscle strength testing showed that most muscles recover to grade 3 or 4. Average grip strength recovery, as percentage of the uninjured hand, was 83%. Pinch strength recovery was 75%, 58% and 39% in patients with ulnar, median and combined nerve injuries, respectively. The RIHM measurements revealed a poor recovery of the ulnar nerve innervated muscles in particular (26-37%). No significant correlation (Pearson) was found between the measurements of the RIHM and grip strength. Pinch strength was significantly correlated with strength of the abduction of thumb and opposition of the thumb strength (r 0.55 and 0.72, p = 0.026, 0.002) as measured with the RIHM. While manual muscle strength testing and grip strength measurements show a reasonable to good recovery, measurements of the intrinsic muscles by means of the RIHM showed poor recovery of intrinsic muscle strength after peripheral nerve injury. No correlation was found between the recovery of intrinsic muscle strength and grip strength measurements.

Measuring the strength of the intrinsic muscles of the hand in patients with ulnar and median nerve injuries: reliability of the rotterdam intrinsic hand myometer (RIHM)

Purpose To determine the reliability and measurement error of measurements of intrinsic muscle strength of a new hand-held dynamometer (the Rotterdam Intrinsic Hand Myometer [RIHM]). Methods With the RIHM we obtained repeated measurements of the intrinsic muscle strength of the hand in 27 patients with peripheral nerve injury of the ulnar and/or median nerve in different stages of rehabilitation. The average time period after injury was 4.4 years (range, 99 days–11 years). Results Differences between 2 measurements greater than 6.3 N were interpreted as a real change in assessing the strength of the abduction of the little and index finger; for the median innervated muscles of the thumb this value was 16 N. Conclusions In patients with nerve injuries the muscle strength is usually assessed with manual muscle strength testing and grip- and pinch-strength dynamometers. Preferably the intrinsic muscle strength should be measured in isolation and quantitatively. The RIHM is a new dynamometer that allows for measurements of the intrinsic muscle strength in isolation with reliability comparable to grip and pinch measurements.