The concurrent validity of a hand-held versus a stationary dynamometer in testing isometric shoulder strength.
METHODS
Clinical Measurement-Validity.


BACKGROUND
Validity of the JTech PowerTrack II hand-held dynamometer (JTech; JTech Medical, Salt Lake City, UT) for measuring shoulder strength has yet to be established.


OBJECTIVE
To examine the concurrent validity of isometric strength scores obtained with the JTech PowerTrack II, and on a stationary dynamometer, the LIDO WorkSET (LIDO; LoredanBiomedical, West Sacramento, CA).


METHODS
Thirty-eight subjects performed three maximal efforts of shoulder flexion, abduction, and external rotation on a single occasion on the two dynamometers. Two testers were randomly assigned to administer the tests.


RESULTS
Pearson correlations between the scores on the two dynamometers (r.0.81) indicated a good concurrent validity. Correlations were similar when the results were subdivided by tester or gender.


CONCLUSIONS
This study suggests that either the JTech PowerTrack II or LIDOWorkSET provide comparable scores for shoulder strength. Although not interchangeable because of the differences in units of measurement, the relative conclusions about strength should be similar, regardless of which instrument is used.


METHODS
Not applicable.
Roy
Jean-Sébastien
JS
School of Rehabilitation Sciences, McMaster University, Hamilton, Ontario, Canada. jean-sebastien.roy.1@ulaval.ca
MacDermid
Joy C
JC
Orton
Brock
B
Tran
Thomas
T
Faber
Kenneth J
KJ
Drosdowech
Darren
D
Athwal
George S
GS
D000328:Adult; D004867:Equipment Design; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D011897:Random Allocation; D012399:Rotation; D012494:Sampling Studies; D012785:Shoulder Joint / Q000502:physiology*