Movement-evoked pain is not associated with pain at rest or physical function in knee osteoarthritis.

INTRODUCTION: Knee Osteoarthritis (KOA) is mainly characterized by pain. The assessment of KOA-related pain frequently focuses on different constructs subject to sources of bias or drawbacks, as the classical Pain at Rest (PAR). Movement-evoked pain (MEP), recently defined as 'pain during walking', emerges as a differential concept, since PAR and MEP are driven by different underlying mechanisms. Given the novelty of the MEP approach, its association with PAR or with different performance-based tests has not been studied in KOA yet. MATERIALS AND METHODS: A cross sectional study was conducted. PAR was measured, alongside the performance of four mobility tests and their corresponding MEP: Timed Up and Go Test, 10-metre Walk Test, 2-Minute Walk Test, and 6-Minute Walk Test. Association and agreement were explored for MEP versus PAR, while the correlation of the tests versus each corresponding MEP-measure was assessed. RESULTS: Neither association nor agreement were found in the duality MEP versus PAR. Also, the lack of association between the performance of a mobility test and the perceived level of pain during the development of the test was stated. CONCLUSION: Movement-evoked pain is neither related to pain at rest nor to functional performance in subjects affected by knee osteoarthritis. The results from our study suggest that MEP and pain at rest measure and refer to different constructs in knee osteoarthritis. The implementation of MEP as an outcome in exercise-therapy could enhance the tracking of results, as well as the development of tailored interventions under different conditions. SIGNIFICANCE: This research elucidates the relevance of MEP, recently defined as 'pain during walking', through the analysis of its association with PAR and with functional performance (measured through four mobility tests) in knee osteoarthritis. The results from our study highlight the absence of either association or agreement between MEP and PAR, fact that supports and endorses the idea that both concepts measure and refer to different constructs in knee osteoarthritis.

Concurrent validity of the 2-and 6-minute walk test in knee osteoarthritis.

BACKGROUND: The 6-Minute Walk Test (6MWT) is frequently used for the assessment of walking distances in several conditions, as knee osteoarthritis, but it can be both time-consuming for the researcher or clinician, and exhausting of painful for the subject suffering from this condition. The objective of our study was to analyze the concurrent validity of the 2-Minute Walk Test (2MWT) for patients with knee osteoarthritis compared to the 6-Minute Walk Test (6MWT). METHODS: Cross-sectional validation study. Scores from the 6MWT of 42 ambulatory patients affected by knee osteoarthritis were compared to those from the shorter 2MWT. An initial correlation test was used to assess correlation between both measures, and a subsequent univariate regression analysis was performed with the aim of comparing the estimated outcomes of the 6MWT versus the actual 6MWT. RESULTS: The scores from the 2MWT and 6MWT showed excellent correlation (Pearson's correlation coefficient r = 0.976; p-value < 0.001); the predictive equation based on the scores from the 2MWT (R2 = 0.952, p-value < 0.001) estimates the 6MWT scores with a relative error of 3.23%. CONCLUSIONS: The 2MWT may be a practical assessment tool in replacement for the 6MWT in clinical assessment due to its low burden on patients and as a means of improving efficiency in a timely manner.

The pain attitudes and beliefs scale for physiotherapists: development and psychometric assessment of the Spanish version among physiotherapy students.

INTRODUCTION: Pain might be approached from a biomedical or biopsychosocial perspective. There is a lack of research on the attitudes and beliefs about pain among physiotherapy students. In this context, the Pain Attitudes and Belief Scale for Physiotherapists (PABS-PT) is an instrument widely used from a clinical and educational perspective, but its psychometric properties have not yet been tested in a student-based population. OBJECTIVE: To develop the Spanish version of the PABS-PT scale and to assess its psychometric properties among students in physiotherapy. METHODS: The study was carried out among 103 students in their final years of academic studies in the Degree in Physiotherapy in the University of Murcia (Spain). Sociodemographic and PABS-PT related variables were collected. The instrument was translated into Spanish and tested through factor analysis, internal consistency, test-retest reliability, and known-groups validity. The 95% minimal detectable change of the instrument was also calculated. RESULTS: The factor analysis revealed two factors within the instrument: Biomedical (9 items) and Biopsychosocial (7 items) factors, with Cronbach's alpha values of 0.730 and 0.708, respectively. The Intraclass Correlation Coefficient (3,2) was 0.851 for the Biomedical factor and 0.699 for the Biopsychosocial factor. The minimal detectable changes (95% CI) for the Biomedical and Biopsychosocial factors were 6.01 and 5.56, respectively. The pre-specified hypothesis for the known-groups validity test was met and revealed large effect sizes (d = 1.24). CONCLUSION: The Spanish version of the instrument PABS-PT-SP covers two factors. It shows satisfactory psychometric properties and it is therefore an effective framework to discriminate between the biomedical and/or biopsychosocial thoughts and attitudes toward pain in physiotherapy.

Addition of tDCS and TENS to an education and exercise program in subjects with knee osteoarthritis: A study protocol.

BACKGROUND: Knee osteoarthritis often leads to chronic pain that frequently becomes disabling.Osteoarthritis has been linked to maladaptive plasticity in the brain, which can contribute to chronic pain. Therapies including neuromodulation and peripheral electrical stimulation are used to counteract the maladaptive plasticity of the brain. OBJECTIVE: To determine the efficacy of the addition of tDCS and TENS to an education and exercise program in reducing pain. METHODS: Over a 2-week study period, 60 participants will complete an exercise and educational intervention. Eligible participants accepting to participate will be subsequently randomized into one of the three treatment groups: 1) Active Transcranial Direct Current Stimulation (tDCS) and active Transcutaneous Electrical Nerve Stimulation (TENS); 2) Active tDCS and sham TENS; 3) Sham tDCS and sham TENS. RESULTS: The primary outcome will be subjective pain intensity. SECONDARY OUTCOMES: quality of life, physical function, central sensitization, and pain adjuvants (uncertainty, catastrophizing kinesiophobia, adverse events). CONCLUSION: This clinical trial will provide data on the effect that the addition of tDCS and/or TENS to an education and exercise program may have to counteract maladaptive plastic changes and improve the benefits of exercises, and whether the combination of both neuromodulator techniques may have a higher magnitude of effect.