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.

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.