The inter-examiner reliability and comparison of motion palpation findings of the knee joint in patellofemoral pain syndrome and asymptomatic knee joints

Abstract

Motion palpation is used to assess the functional status of a joint and is defined as “The manual palpation of bony structures and soft tissues, through pressure applied in various directions of joint motion to ascertain areas of joint hypomobility and hypermobility.” Motion palpation is a collection of manual examination procedures, used to identify the site and characteristics of altered joint motion and which has been an important part of chiropractic since its inception.

One of the most important goals for any clinical instrument is for it to have good reliability and reproducibility, this is because the clinical value of a test must be demonstrated before the results are considered valid. The extent to which a repeated test will produce the same result when evaluating an unchanged characteristic is its reliability. Reliability is evaluated by multiple blinded measurements performed on a sample of subjects. Inter-examiner reliability evaluates the consistency of different examiners and is determined through repeated assessment by two or more raters.

Objective The aim of this study was to determine the inter-examiner reliability of motion palpation of knee joints with patellofemoral pain syndrome and asymptomatic knee joints, and to compare the inter-examiner reliability of motion palpation between the two groups.

Method This quantitative, inter-examiner, clinical reliability study, included 30 patients each with one knee with patellofemoral pain syndrome and one asymptomatic knee. Each patient had both of their knees motion palpated by three independent examiners blinded to which was the symptomatic knee. The examiners were senior student interns at the DUT Chiropractic Clinic. The motion palpation findings were recorded and statistically analyzed through the SPSS statistical package. Fleiss Kappa statistic was used to give a Kappa score for each direction of motion palpation and these scores evaluated the inter-examiner reliability of motion palpation in the symptomatic and the asymptomatic knee. A comparison of the inter-examiner reliability of motion palpation between the two groups was performed using a paired Wilcoxin signed ranks test.

Results The Kappa scores for motion palpation ranged from -0.2081 to 0.1802 for the symptomatic knee joint and -0.2836 to 0.0339 for the asymptomatic knee. This shows poor agreement in both cases. There was no significant difference in Kappa values (p= 0.609) for the two groups for the Wilcoxin signed ranks test and the number of positive and negative ranks were similar. This indicates that the reliability of motion palpation in both groups was similar.

Conclusion It was concluded that inter-examiner reliability of motion palpation of the knee joint was poor in knees with patellofemoral pain syndrome and in knees that were asymptomatic. Motion palpation was found to be equally reliable in both groups, indicating that motion palpation of a symptomatic joint does not improve its reliability. This research suggests that motion palpation should be used together with other diagnostic tests to identify patellofemoral pain syndrome as it is not a reliable tool when used in isolation.