The reliability of the Trendelenburg test

Authors:
  • Frost Richard
Type of Publication: Generic
Institute: British College of Osteopathic Medicine
Entry date: -0001 November, 30
Status: Finished Recommended: No
Country: United Kingdom Language: English

Abstract

For any orthopaedic test or diagnostic procedure to be considered useful in clinical practice it must be shown to be a valid test and also show reproducibility as measured by its reliability. Only when reliability is established can a test or procedure form the basis for diagnosis. Reliability is the consistency or repeatability of measurements, that is, the degree to which repeated measurements will agree. This study was carried out to investigate the reliability of the Trendelenburg test using a blinding procedure which required that the subjects were blind to the procedural parameters. Statistical analysis revealed that there was a significant association between hip pathology and a positive Trendelenburg sign. There was a 100% specificity level (proportion of subjects without hip pathology testing negative) but only a 29% sensitivity level (proportion of hip pathology subjects testing positive) with the test. The results from this study therefore suggest that where there is no hip pathology present there is a high accuracy level for the Trendelenburg test. However, where there is hip pathology the sensitivity level is poor. Consequently, this study can only confirm a certain degree of reliability of the Trendelenburg test as a diagnostic tool. Ideas for Further Research. The presence of pain, poor balance and either a lack of co-operation or understanding by the patient can lead to 'false-positive tests' because the test cannot be properly performed. The reason for false-negative tests maybe that the subject uses muscles above the pelvis to elevate the non-weight-bearing side of the pelvis, or shifts the torso well over the weight-bearing side, These can be called 'trick movements'. False-negative and false-positive responses therefore may occur and their interpretation needs to be clarified to ensure that the test is properly performed. Further research may be useful with respect to looking at the results of the tests both when hip pathology is the working diagnosis and when it is ruled out. It would be of interest to conduct a study looking into all cases of hip pain and investigate the frequency with which Trendelenburg tests give apparent false negatives and positives. Ideally, the investigation would be best carried out by one practitioner who both performed and documented the tests and also carried out the case history and examination as subjects assessed by different practitioners allow no continuity in the application of the tests or in the approach to evaluation and diagnosis. At present a large proportion of the previous research into the orthopaedic tests for hip pain has either been carried out or performed for chiropractors. Wider research and surveys by and of osteopaths on the Trendelenburg test would further facilitate the discussion and perhaps clarify its perceived and actual usefulness.