SCIENTIFIC/CLINICAL ARTICLE

JHT READ FOR CREDIT ARTICLE #170.

The Reliability of One vs. Three Trialsof Pain-free Grip Strength in Subjects

with Rheumatoid Arthritis

Donna Kennedy, BSc OT, MSc, CHTImperial College Healthcare NHS Trust, Charing CrossHospital, Occupational Therapy Department, London,United Kingdom

Christina Jerosch-Herold, DipCOT, MSc, PhDUniversity of East Anglia, Norwich, United Kingdom

Mary Hickson, SRD DipADP, PhDImperial College Healthcare NHS Trust, London, UnitedKingdom

This article is adapted from the presentation, “The Reliability ofOne vs. Three Trials of Pain-free Grip Strength in Subjects withRheumatoid Arthritis,” presented at the Best Scientific Paper ses-sion at ASSH/ASHT in San Francisco in September 2008.

A grant for this study was received from the Trustees of theImperial College Health Care NHS Trust.

Correspondence and reprint requests to Donna Kennedy, BScOT, MSc, CHT, Occupational Therapy Department, ImperialCollege Healthcare NHS Trust, Charing Cross Hospital, FulhamPalace Road, London W6 8RF, United Kingdom; e-mail:<Donna.kennedy@imperial.nhs.uk>.

0894-1130/$ - see front matter � 2010 Hanley & Belfus, an imprintof Elsevier Inc. All rights reserved.

doi:10.1016/j.jht.2010.05.002

384 JOURNAL OF HAND THERAPY

ABSTRACT:Study Design: Measurement Reliability. The purpose of the

study was to evaluate the testeretest reliability of one vs. themean of three trials of pain-free grip strength in participants withrheumatoid arthritis (RA). The study used was a repeated-measures, crossover design. Pain-free grip strength was measuredwith the Biometric E-Link Evaluation System V900S (Unit 25,Nine Mile Point Ind. Est., Gwent UK NP11 7HZ), pain levels re-corded before and after grip tests with visual analog scale. Highlevels of testeretest reliability (intraclass correlation coef-ficient$ 0.91) were found for both one trial and the mean of threetrials of pain-free grip strength testing. Median values of gripstrength for both methods produced comparable results. Clinicallysmall but statistically significant increases in pain (p# 0.01) werefound. One trial of pain-free grip strength is reliable and may savevaluable clinical timewhile reducing the assessment burden placedon patients with RA.

Level of Evidence:N/A.

J HAND THER. 2010;23:384–91.

Rheumatoid arthritis (RA) is a progressive, sys-temic autoimmune disease.1 In patients with RA,chronic inflammation of the synovium, or joint lining,can lead to the destruction of joint surfaces and mayresult in joint deformities.2 RA commonly affects thesmall distal joints and it is estimated that over 90%of patients suffer from involvement of the hand andwrist joints.3 Patients with rheumatoid hand diseasemay present with pain and swelling, limitations injoint range of motion, muscle weakness, and joint de-formity.4 Consequently, these impairmentsmay result

in diminished hand function and limitations in activ-ities of daily living for patients with RA.

Assessment of the rheumatoid hand often includesthe evaluation of isometric grip strength. Althoughthere is evidence supporting the use of a standard-ized protocol for the evaluation of grip strength, thisprotocol has not been evaluated in persons withrheumatoid hand disease and at present there is noaccepted gold standard for the evaluation of gripstrength in patients with RA.5e7

The standardized assessment of grip strength maynot be appropriate for patients with RA as thesepatients often present with hand pain, and proximalupper limb pain and weakness.8,9 Additionally, thereis evidence that during grip strength evaluation, RApatients demonstrate greater fatigue effects and expe-rience more pain than other patient groups.10,11

Modifying the standardized evaluation and assessingone trial of pain-free grip strength with a supportedinstrument warrants consideration. This proceduremay allow for the reliable evaluation of grip strengthwhile controlling for proximal limb weakness andhand pain in patients with RA, thereby minimizingthe assessment burden placed on patients with achronic, painful condition.

LITERATURE REVIEW

A review was conducted to synthesize the availableresearch literature and to inform the study protocol. Amultiple-stage search was conducted using AMED,CINAHL, EMBASE, andMedline electronic databasesfrom their inception to July 2008 using the terms“rheumatoid arthritis,” “hand,” “grip,” “Jamar dyna-mometer,”a “dynamometry,” “isometric,” “power,”“force,” “strength,” “assessment,” “evaluation,”“test,” “performance,” “outcome measure,” “pain-free,” “sphygmomanometer,” “Grippit,”b “MIE digitalgrip analyser,”c and “Biometric E-Link EvaluationSystem.”d Reference lists were hand searched for fur-ther references not identified through the searches.Inclusion criteria were English language studies andstudies investigating the testeretest or intrarater relia-bility of grip strength evaluation in adults and adultswith RA.

Testeretest Reliability of Grip StrengthEvaluation

Reliability may be described as the degree to whicha measure is consistent and free from error.12

Assessment tools, however, are seldom perfectly reli-able. Measures may be affected by both systematicerrors, such as a tool not being properly calibrated,and by random errors such as fatigue or inattentionto instructions. Grip strengthmeasurements generatecontinuous data and therefore reliability estimatesshould be reportedwith both an intraclass correlationcoefficient (ICC) and the standard error of measure-ment (SEM).13 The ICC provides a point estimate ofreliability, whereas the SEM quantifies the randomerror in measurements and aides in the clinical inter-pretation of results.

In 1981, the ASHT recommended that the assess-ment of grip strength should calculate the mean ofthree successive trials of maximal effort measuredwith the participant seated and positioned with theshoulder abducted, the elbow flexed to 90 degrees,and the forearm and wrist in neutral position.6 Thisassessment guideline has been supported by studiesof asymptomatic populations and with RA sub-jects.7,10,11,14e17 However, the body of evidence sup-porting the reliability of grip strength assessmentwith RA subjects is inconclusive because of method-ological flaws, including tool selection, sample size,and the use of inappropriate statistical tests foranalysis.

Fatigue Effects Associated with Grip StrengthEvaluation

A fatigue effect, or trend for decreasing grip scorescan be seen when testing multiple trials of gripstrength.9,18e20 This effect is reported to be greater

still in patients with RA.10 The duration of rest pro-vided between grip trials and between grip testshas been found to affect grip strength and the reliabil-ity of grip strength testing. However, the effect of theduration of rest between trials and between tests hasnot been previously investigated with an RA popula-tion. A 1-minute recovery between trials is shown todecrease fatigue effects in asymptomatic partici-pants,18 whereas a 15-minute rest between tests isadequate to allow for recovery from fatigue ordiscom-fort.21A testingprotocolusinga 1-minute rest betweengrip trials anda 15-minute recovery between testsmaycontrol for fatigue in participants with RA, therebyimproving the reliability of grip strength evaluation.

Diurnal Variability in Grip Strength

Diurnal variation affects the grip strength of bothhealthy persons and those with RA. Grip strengthin RA patients is significantly reduced in the earlymorning, increases sharply until approximately10:00 AM, levels off in the afternoon, and falls in theevening.15,22,23 This suggests that repeated-measuresstudies of grip strength in participants with RAshould avoid testing in the earlymorning and eveningand should use a short retest interval to control fornaturally occurring variation in grip strength.

The Reliability of Grip Assessment withModified Testing Protocols

The effect of hand and arm position on the relia-bility of grip strength assessment has been investi-gated extensively. A high degree of repeatability hasbeen reported in a range of different postures orpositioning of the patient provided that the samepositioning is used across repeated trials. Studieswith asymptomatic individuals have evaluated gripwith varying wrist postures24; varying degrees ofelbow flexion25; and with the use of optional armand trunk positions26; with all of these studies report-ing ICCs$ 0.90. This suggests that modifying theASHT standardized assessment of grip to supportthe participants arm and the dynamometer on thearmrest of the chair should not affect the reliabilityof assessment, providing this testing procedure is im-plemented consistently.6

The Effect of the Number of Trials onReliability in Grip Evaluation

Studies of the effect of the number of grip trials onreliability have reported contradictory results.Mathiowetz et al.7 and Hamilton et al.20 studiedtesteretest reliability in asymptomatic participantsand reported a higher degree of reliability for themean of three trials as compared with one trial ofgrip strength. Mathiowetz et al.7 investigated

OctobereDecember 2010 385

reliabilityusingPearsonproductemoment correlationcoefficients (right hand mean of three trials r¼ 0.883vs. one trial r¼ 0.788, left hand mean of three trialsr¼ 0.929 vs. one trial r¼ 0.864), and Hamilton et al.20

investigated reliability using ICCs (right hand meanof three trials ICC¼ 0.964 vs. one trial ICC¼ 0.949,left hand mean of three trials ICC¼ 0.954 vs. one trialICC¼ 0.935). Similarly, MacDermid et al.14 reporteda higher degree of inter-rater reliability for the meanof three trials of grip strength in both asymptomaticparticipants (ICC¼ 0.98, confidence interval [CI]:0.96e0.99 vs. ICC¼ 0.94, CI: 0.89e0.97) and partici-pants with cumulative trauma disorder (ICC¼ 0.96,CI: 0.93e0.98 vs. ICC¼ 0.93, CI: 0.86e0.96), respec-tively. In contrast, in a study of symptomatic andasymptomatic participants, Coldham et al.21 reportedthe highest testeretest reliability for one grip strengthtrial vs. themeanof three trials, respectively, in asymp-tomatic participants (ICC. 0.95, CI: 0.89e0.98 vs.ICC¼ 0.85, CI: 0.67e0.94) andparticipants after carpaltunnel decompression (ICC¼ 0.97, CI: 0.94e0.99 vs.ICC¼ 0.94, CI: 0.80e0.98). However, Coldham et al.21

reported a higher degree of reliability for the mean ofthree trials as compared with one trial in participantsafter flexor tendon repair (ICC¼ 0.98, CI: 0.96e0.99vs. ICC¼ 0.96, CI: 0.91e0.98).

Comparison of these reliability results is difficultand possibly inappropriate because of differences instudy methodology, sample sizes, and participantcharacteristics.13 Mathiowetz et al.7 and Hamiltonet al.20 counted the first of three grip trials as one trial.However, it has been suggested thatwith three trials ofgrip, the standard deviation of the first grip in eachhand is higher, suggesting a higher range of error,15

which may account for the lower degree of reliabilityreported for one trial of grip in these study findings.The contradictory results reported by MacDermidet al.14 and Coldham et al.21 may have been becauseof differences in methodology (MacDermid et al.14

studied inter-rater reliability, whereas Coldhamet al.21 studied testeretest reliability) and differencesin patient groups. Participants in the Coldhamet al.’s21 carpal tunnel decompression group mayhave presented with a tender postsurgical scar in thepalm and may have experienced pain with grippingthe hard dynamometer handle. Pain experienced ongripping may have affected grip performance oversubsequent trials and improved the reliability of onegrip trial as compared with the mean of three.

Although there is no agreement onminimal accept-able reliability, it has been suggested that reliabilityestimates using ICCs should exceed 0.90 to ensureadequate reliability of a clinical measurement.12

Despite Hamilton et al.,20 MacDermid et al.,14 andColdham et al.21 reporting contradictory findings forthe reliability of the mean of three vs. one trial ofgrip strength, these studies are consistent in thatthey report an ICC. 0.90 for the reliability of one trial

386 JOURNAL OF HAND THERAPY

of grip strength. This would suggest that one trial ofgrip strength demonstrates a clinically acceptable de-gree of reliability with both symptomatic and asymp-tomatic participants and warrants investigation inparticipants with RA.14,20,21

The Reliability of Pain-Free Grip Assessment

The presence of pain may affect the reliability ofgrip strength evaluation.17,27 In a review of outcomemeasures, Macey and Burke28 suggest if an assess-ment is to be an objectivemeasure, it must be immunefrommodification by the patient. It is reasonable thatmotivation and performance will be less affected bypain, or fear of pain, with the evaluation of pain-freegrip strength in symptomatic participants. Pain-freegrip strength is evaluated by instructing the partici-pant to squeeze the dynamometer handle and stopwhen they begin to feel discomfort, as opposed toworking maximally.29,30 Pain-free grip strength hasbeen studied in participants with painful upper limbconditions, including lateral epicondylitis29,31 andnonspecific regional pain (NSRP),30 and is reportedto have a high degree of testeretest reliability in thesepopulations. The standardized assessment of maxi-mal grip strength6 in persons with RA may be con-founded by fatigue, hand and wrist pain, andproximal limb pain and weakness, affecting the relia-bility and validity of grip strength evaluation in thispopulation. The evaluation of pain-free gripstrength29e31 and one trial of grip strength14,20,21

have demonstrated a high degree of reliability withother populations, but have yet to be explored withan RA population.

STUDY AIMS

1. To establish the testeretest reliability of one vs. themean of three trials of pain-free grip strength witha supported Jamar dynamometera in persons withRA.

2. To evaluate the level of pain experienced by RApatients during grip tests and to compare painseverity for one and three trials of grip.

METHODOLOGY

Ethical approval for this study was granted by theCharing Cross Hospital Research Ethics Committee.An a priori sample size calculation based on therecommendation that the magnitude of the ICC forclinical measurements should exceed 0.90 to ensureadequate reliability,12 and an estimated ICC of 0.965derived from similar grip strength studies20,21 deter-mined that this study would have 80% power with asample of 24 participants and 90% power with a

TABLE 1. Subject Group Demographics

Number of cases¼ 25Age (yr)Mean (standard deviation) 62.5 (10.6)Range 42e86Gender (%)

Female 20 (80%)Male 5 (20%)

Hand dominance (%)Right 23 (92%)Left 2 (8%)

Median initial pain rating on 100-mm visual analog scaleRight hand 5Left hand 6

sample size of 31 participants. Using consecutivesampling, patients referred to the OccupationalTherapy Department were recruited by the lead in-vestigator (DK) between February and September2008. Inclusion criteria included adults over the ageof 18 years with an established diagnosis of RA, con-firmed on routine clinical and laboratory tests.Participants had well-controlled rheumatoid disease,having been on a regime of disease modifying drugsfor greater than three months and with no present ac-tive inflammation. Exclusion criteria included a his-tory of hand surgery in the past year, a history ofneurological disease or peripheral neuropathy or ahistory of significant hand trauma. Fully informedwritten consent was obtained from all the partici-pants before enrollment into the study.

This quantitative study used a repeated-measuresdesign, whereby one group of participants was testedunder all conditions with each subject acting as hisown control.12 As repeated trials of grip strengthmaybe affected by order effects including fatigue, a Latinsquare design was used to systematically vary theorder of tests and control for any order effects.12

Each participant was tested under each of the fourconditions which were a single trial of pain-freegrip strength of left hand followed by right hand(A), a single trial of pain-free grip strength of righthand followed by left hand (B), three consecutivetrials of pain-free grip strength alternating betweenleft and right hands (C), and three consecutive trialsof pain-free grip strength alternating between rightand left hands (D). The order of testing for eachparticipant was prerandomized (e.g., participant1 was assessed using order ABCD, participant 2was tested using order BCDA, and so on). For thethree repeated trials of hand grip strength, a 1-minuterest was used between trials. Between each of thefour conditions (A, B, C, and D), each patient had a15-minute break between testing. All the data collec-tion for each participant was completed within onehour on the same day, with all tests starting after10 AM and completed before 4 PM to control for diur-nal variation.

Outcome Measures

Grip strength was measured with the BiometricE-Link Evaluation System V900S (Biometrics Ltd,Gwent UK),d a calibrated, computerized system in-corporating a modified Jamar dynamometer,a mea-suring strength to the tenth of the kilogram. Thedynamometer used in this study was calibrated bythe manufacturer before the start of the study withthe same dynamometer being used throughout thestudy. Pain intensity was evaluated with a visual ana-log scale (VAS). TheVASwas selected for this study asit has demonstrated acceptability with rheumatologypopulations,32,33 is more sensitive in detecting small

changes in pain and has a higher testeretest reliabilitythan verbal rating scales for pain.33

Procedure

Participants were seated on a standard straight-backed armchair with their arm supported. Thedynamometer was supported on the armrest duringtesting. The height of the chair and armrest was notmodified to control for height differences betweenparticipants; therefore, the angle of shoulder abduc-tion may have varied between participants. Theparticipants were asked to complete a VAS for painat the start and finish of each of four grip strengthtests.

Participants had their grip strength measured forall the four conditions using the second handleposition of the dynamometer. Before testing, partic-ipants were instructed to hold the dynamometerhandle and slowly squeeze as hard as they could,without causing themselves pain and to begin grip-ping when instructed to squeeze and stop wheninstructed to relax. Standardized instructions wereread to each participant: “Are you ready? Squeezetwo, three, four, relax.” Participants were blindedfrom their results during testing.

Data Analysis

Data were analyzed using version 16.0 of theStatistical Package for the Social Sciences (SPSS Inc.,Chicago, IL). Testeretest reliability (intrarater relia-bility) was calculated using ICCs and the 95% CI. ICC(model 2) was chosen for analysis, as the procedureand instrument used in this study may be general-ized to a wide population of clinicians and readilyimplemented in clinical practice.12,13 SEM was alsocalculated. SEM gives an absolute estimate of reliabil-ity and can be used to interpret change in an individ-ual. Using a 95% CI (SEM95), it can be said that anindividual’s true score falls within62 SEM. The non-parametric Wilcoxon signed-rank test was used toinvestigate the differences between grip strength

OctobereDecember 2010 387

TABLE 2. Descriptive Statistics for Grip Strength Averaged from Both Tests for One Trial and the Mean of Three Trials,for the Left and Right Hands

Grip Test Median (kg)InterquartileRange (kg) Minimum (kg) Maximum (kg)

Comparing Left withRight Trials, Differencein Kilograms (p Value)

One trial left 7.8 5.9e12.2 2.6 22.3 0.44 (0.66)One trial right 8.8 5.6e13.2 2.6 25.0Mean of three trials left 8.6 5.9e12.6 2.3 20.8 0.08 (0.94)Mean of three trials right 9.2 5.9e13.4 1.5 26.9

values over grip tests and the change in pain scoresover grip tests, as grip and pain data did not followa normal distribution.

RESULTS

Thirty patients were invited to participate in thisstudy, of which 25 consented and were enrolled(Table 1). The participants were predominantly fe-male and right hand dominant, with hand domi-nance defined as the hand used for writing. Allinitial pain scores as rated on VAS were low.

Grip strength measurements in this group of RAparticipants were not normally distributed and werepositively skewed. Descriptive statistics for gripstrength are provided in Table 2. The median gripstrength values were higher for the mean of threetrials than with single trials for both hands but com-paredwithWilcoxon signed-ranks test, the differencefor both hands is of the same magnitude and is notstatistically significant (0.605 kg, p¼ 0.545).

The ICCs for all grip strength tests in this studywere greater than 0.90 demonstrating excellenttesteretest reliability (Table 3). The 95% CI for theICCs were wider for one trial with the right handand three trials with the left hand, with the lower con-fidence limit less than 0.90 for these tests. The SEMwas 1.5 kg or less for all the tests, with the smallestSEM of 0.8 kg for one trial of grip left hand.

Pre- and post grip test pain scores were comparedwith the nonparametric Wilcoxon signed-rank testand are presented in Table 4. The difference in painover the single trials of grip with the left and righthands and three trials of grip with the left hand,although very small were statistically significant.

TABLE 3. Testeretest Reliability of Grip Strength, forLeft and Right Hands and One and the Mean of Three

Grip Trials

Grip Test ICC 2,1 95% CI SEM (kg)

One trial left 0.96 0.911e0.982 0.8One trial right 0.92 0.828e0.964 1.2Three trials left 0.91 0.808e0.962 1.5Three trials right 0.97 0.922e0.985 1.2

ICC¼ Intraclass correlation coefficient; CI¼ confidence interval;SEM¼ standard error of measurement.

DISCUSSION

In this study, excellent testeretest reliability wasfound for one trial and the mean of three trials ofpain-free grip strength in patients with RA. The 95%CIs for the ICCs were small for all the four tests withlower limits greater than 0.75, suggesting high preci-sion of the reliability estimate. These findings agreewith the work of Coldham et al.21 demonstrating

388 JOURNAL OF HAND THERAPY

excellent testeretest reliability for the evaluation ofone trial of grip strength in symptomatic personsand with Stratford et al.31 and Nitschke et al.30 forthe reliability of pain-free grip strength in popula-tions with painful conditions. The SEMs in this studywere small, ranging from 0.8 kg for one trial of gripwith the left hand, to 1.5 kg for three trials of gripwith the left hand. Clinically, this implies that achange as small as 61.6 kg (2 SEM) is indicative ofa true change in pain-free grip strength.12

Pain with Grip Strength Evaluation

Participants in this study rated their pain on a100 mm VAS before the start of testing, reporting amedian pain rating of six for the left hand and five forthe right hand. However, pain was not an inclusioncriterion, nor was the use of pain medication consid-ered an exclusion criterion in this study. Pain wasevaluated as a dependent variable to ensure that theevaluation of “pain-free” grip strength was indeedpain free, as this has not been reported in previousstudies.29,30,31 Although very small, there was a sta-tistically significant change in pain after one trial ofgrip with the left hand, one trial of grip with the righthand, and three trials of grip with the left hand, withthe change in pain approaching significance for threetrials of grip with the right hand. The magnitude ofthe change in pain ranged from 1 to 3.5 mm for allthe tests. Although statistically significant, thischange is probably not clinically significant. Therewas no significant difference comparing the pain ex-perienced in tests with one trial of grip with tests withthree trials of grip, implying that although there wasan increase in pain after one trial of grip, this increase

TABLE 4. Comparison of Pain Ratings with 100-Point Visual Analog Scale Completed before and after Grip Tests

Grip TestMedian Score (Interquartile Range)

before Grip TestMedian Score (Interquartile Range)

after Grip TestWilcoxon Signed Rank Test for

Difference in Pain Rating (p Value)

Left single 9.5 (2.5e24.5) 11.0 (3.0e35.5) 3.38 (0.001)Left three 7.5 (2.0e27.0) 8.5 (2.7e40.5) 2.88 (0.004)Right single 11.0 (2.2e28.7) 13.0 (2.0e33.5) 2.58 (0.01)Right three 7.0 (1.8e31.3) 10.5 (2.5e35.7) 1.83 (0.067)

was not greater still after three trials of grip.Although it is unclear why the change in pain forthree trials of grip with the right hand was not statis-tically significant in this study, this may be becausemost (92%) of the participants in this studywere righthand dominant and therefore would have been moreaccustomed to repetitive gripping with the righthand.

Order Effects in Grip Strength Evaluation

No fatigue effect was demonstrated in this study.Comparing the four tests with three trials of grip inthis study, no consistent pattern of decline was noted.The difference in medians between grip trials wassmall and did not approach significance. The find-ings of this study suggest that a 1-minute recoverybetween grip trials will control for fatigue effectswhen testing three trials of grip strength in partici-pants with RA.

Limitations of This Study

The RA patients who participated in this study hadwell-controlled rheumatoid disease and reported alow level of pain before testing. Comparison of thereliability results between this and other studies canonly bemadewhere size and attributes of the samplestested are similar. Results may vary in a population ofpatients with less well-controlled rheumatoid diseaseor with a greater degree of pain. This study used ashort retest interval of 15 minutes for recovery frompossible fatigue. Thehighdegree of reliability and lowSEMs found in this study may be affected if testingwith an alternative rest interval.

Implications for Practice

The results of this study demonstrate high levels oftesteretest reliability (ICC$ 0.91) for the evaluationof one and the mean of three trials of pain-free gripstrength testing using the Biometric E-Link evalua-tion system in participants with RA. Evaluation ofpain-free grip produced clinically small although sta-tistically significant increases in pain (p# 0.01). Thedifference in pain for tests with one trial of grip ascomparedwith tests of three trials of grip was not sta-tistically significant. No fatigue or learning effectswere found on tests of three trials of grip strength.A change in grip strength as small as 1.6 kg may be

indicative of meaningful clinical change in RA pa-tients; therefore, grip should be evaluated with an in-strument with adequate sensitivity to detect thismagnitude of change. The evaluation of one trial ofpain-free grip may save valuable clinical time whilereducing the assessment burden placed on patientswith RA.

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Suppliers

a. Jamar dynamometer, Sammons Preston, Bolingbrook IL, USA.b. Grippit, AB Detector, Goteborg, Sweden.c. MIEDigitalGripAnalyser,MIEMedicalResearchLtd,LeedsUK.d. Biometric E-Link Evaluation System V900S, Unit 25, Nine Mile

Point Ind. Est., Gwent UK NP11 7HZ.

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Record your answers on the Return Answer Formfound on the tear-out coupon at the back of this is-sue or to complete online and use a credit card, go toJHTReadforCredit.com. There is only one best an-swer for each question.

#1. The study compared the

a. validity of comparing grip testing in an RA

population vs. a normal populationb. validity of a single effort vs. the mean of three

trialsc. reliability of a single effort vs. the mean of

three trialsd. reliability of grip tests in an RA population vs.

a normal population

#2. Pain scores were assessed using a

a. VASb. computer detected response from surface

electrodesc. DASHd. 1-5 scale

#3. In assessing reliability the investigatorsemployed

a. a Student T Testb. an ANOVAc. a Pearson correlation coefficientd. an ICC

#4. The authors recommend not testing grip in RApatients in the

a. mid morningb. mid afternoonc. early morning or eveningd. late afternoon

#5. The authors suggest using themean of three trialsclinically

a. trueb. false

When submitting to the HTCC for re-certification,please batch your JHT RFC certificates in groupsof 3 or more to get full credit.

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