Table 1

Operational definitions of domains, psychometric properties and subsets of psychometric properties for the purpose of this review

DomainsPsychometric propertiesSubsets of psychometric propertiesDefinitions adapted from COSMIN recommendations (except where indicated)
ReliabilityThe degree to which scores for (symptomatic or asymptomatic) individuals, who have not changed, are the same for repeated measurement of knee proprioception and free from measurement error.
Test–retestThe extent of agreement in repeated measurements of knee proprioception using a specific test over time.
Inter-raterThe extent of agreement between raters investigating knee proprioception scores on the same individual.
Intra-raterThe extent of agreement between repeated measurements of knee proprioception scores on the same individual by the same rater.
Measurement errorThe systematic and random error of an individual’s score that is not attributed to true changes in knee joint proprioception to be measured.
ValidityConcerns how well the specific knee proprioception test under assessment measures the construct it is designed to measure, e.g. how well a knee JPS test measures the target joint position/angle matching?
Criterion validityThe extent to which knee proprioception measurements are an adequate reflection of a ‘gold standard’ method. As the ‘gold standard’ for each type of knee proprioception test is unclear, assessing the correlation of such tests with a reference standard (criterion) will be attempted.
Concurrent validity*55 56 Addresses how well a knee proprioception test correlates to a reference standard (criterion) or instrument measuring a similar outcome, e.g. correlating the scores of a specific proprioception test such as JPS measured with dynamometer or angular motion chair method to that of position replication using a model, image-recorded angulation (photography method) and/or electrogoniometer method.
Predictive validity*55 56 A focal measure of knee proprioception measured with a specific test at one point is used to predict another criterion measured at a later point of time, e.g. the scores of a proprioception test being used to predict the outcomes of an ACL reconstruction surgery, quality of life, return-to-sport or subsequent injury risk at a later time point.
Construct validityThe extent to which the scores of a specific knee proprioception test are consistent with hypotheses regarding the scores of other measurement methods or differences between known groups, given that the proprioception test validly measures the construct it is purported to measure.
Hypothesis testing: known groups or discriminative validity56 The degree to which the scores of a knee proprioception test can discriminate between groups known to differ in proprioception sense (e.g. individuals with an ACL injury managed conservatively vs. those managed with reconstructive surgery or knee-healthy individuals vs. individuals with an ACL injury).
Hypothesis testing: convergent validity and discriminant (divergent) validity*55 56 The focal measures of knee proprioception tests (e.g. JPS, TTDPM, AMEDA, etc.) show conceptual convergence or divergence between them or with other outcome measures attributed to different constructs such as quantitative sensory testing methods (e.g. mechanical, thermal or electrical pain threshold/tolerance), thigh muscle strength, quality of life, etc. Correlations with related constructs are expected to be higher than those of unrelated constructs.
ResponsivenessThe ability of a knee proprioception test to detect change in proprioceptive ability over time.
Criterion approachA focal measure of knee proprioception is consistent with a gold standard or a reference standard (idem construct validity) over time.
Construct approachA focal measure of knee proprioception is correlated with other outcome measurement instruments or discriminated between subgroups (idem hypothesis testing) or before and after intervention, measured over a period of time.
  • We expect that the definitions will evolve and become more specific because of the study methods, type of data and the findings reported in the eligible articles, further to discussion at team meetings.

  • *Definitions adapted from sources other than the COSMIN.

  • ACL, anterior cruciate ligament; AMEDA, active movement extent discrimination assessment; COSMIN, COnsensus-based Standards for the selection of health Measurement INstruments; JPS, joint position sense; TTDPM, threshold to detect passive motion.