Diadynamic and Exercises in Knee Osteoarthritis
Condition: Osteoarthritis, Knee
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Osteoarthritis represents failed repair of joint damage resulting from stresses initiated by
      any joint or periarticular tissue abnormality. The rate of progression varies among persons
      and within a knee over time.

      The symptoms and signs of knee osteoarthritis include pain, stiffness, reduced joint motion,
      and muscle weakness. Long-term consequences can include reduced physical activity,
      deconditioning, impaired sleep, fatigue, depression, and disability.This reduction in
      activity to avoid pain (kinesiophobia) to evade the onset of pain, especially in the acute
      phase, limiting their compliance with effective rehabilitation strategies such as regular
      exercises.

      Physical medicine has a wide range of analgesic anti-inflammatory and muscle stimulating
      treatment methods. Both diadynamic and TENS currents have become the most frequently
      implemented electrotherapeutic methods. The impact of diadynamic currents consists of
      analgesic effects and specific dynamics during the formation of physiological processes in
      tissues.

      They occur during the administration of the current and lasts up to a few hours after the
      treatment has been terminated. One of the theories explaining the analgesic effect of
      diadynamic currents is the gate control theory of pain by Wall and Melzack. Recently, another
      theory has become very popular. It explains the analgesic effect provoked by bodies
      characterized as polypeptides called endorphins. Electric stimulation using diadynamic
      currents generates an increase in the amount of endorphins in a system.

      Although the analgesic impact of TENS therapy is well known, Diadynamic currents therapies
      have not been studied in knee osteoarthritis pain conditions. Therefore, the aim of the
      present study was to investigate the medium-term effects of Diadynamic currents combined with
      exercise on pain and disability in patients with osteoarthritis of the knee.
    

Detailed description: 
      The study included patients who attended the Special Rehabilitation Services in Taboão da
      Serra-SP, with knee osteoarthritis diagnosed by an independent rehabilitation specialist, and
      fulfilled the following inclusion criteria: (1) aged from 50 and 75; (2) symptomatic knee
      osteoarthritis for at least three months; (3) visual analogue scale12 score above 3 and (4)
      radiographic knee osteoarthritis (uni or bilateral) compatible with Kellgren-Lawrence grade
      two or higher.

      The exclusion criteria were as follows: contraindication to laser application (e.g. cancer
      and insulin-dependent diabetes); inability to perform the assessment or treatment; continuous
      use of anti-inflammatory drugs, symptomatic hip osteoarthritis and physiotherapeutic knee
      treatment within the last 3 months.

      All potentially eligible participants were contacted by telephone and those interested in
      participating were invited to attend a physical examination for inclusion and exclusion
      criterion. All participants were informed about the study and provided informed consent
      before participating. They were assigned by block randomization, stratified according to
      treatment group. An independent researcher not involved in outcome assessment was responsible
      for group allocation, using a computer-generated random number table. Immediately after
      baseline assessment by the blinded assessor, the treating physiotherapist accessed the
      allocation schedule from a centrally located locked cabinet. Patients and the physiotherapist
      responsible for the evaluation and physiotherapist responsible for the treatment were all
      unaware of the randomization results as allocation to groups was concealed.

      Demographic and anthropometric data, the use of pain relief medications, the duration of knee
      pain, the knee range of motion, and a range of patient-reported outcomes were collected at
      baseline (before randomization) and 8 weeks from baseline by the same blinded evaluator.

      The primary outcomes were pain intensity measured by the numeric pain rating scale (0-10)
      with a minimal clinically important change set at two points and disability measured using
      the Lequesne questionnaire, which consists of 11 questions about pain, discomfort, and
      function. Scores range from 0 to 24 (from 'no' to 'extremely severe' dysfunction).

      Secondary outcomes included medication intake (Paracetamol) for knee pain relief, mobility
      and balance, range of motion, muscular strength, and activity. Mobility and balance were
      evaluated by the Timed Up and Go test. The Timed Up and Go test, a measure of functional
      mobility, quantifies in seconds the time that the individual needs to stand up from a chair,
      walk 3m, turn back toward the chair and sit down again. Range of motion of the knees was
      measured with a universal goniometer (AESCULAP). Muscular strength was estimated at maximal
      isometric force for the quadriceps, using a portable dynamometer (Lafayette, USA). Under
      stabilized conditions, patients, sitting with knees flexed at 60 (measured by a goniometer),
      were asked to extend the legs as far as they could. Three attempts were conducted, and the
      mean value was obtained. Muscular strength was estimated at maximal isometric force for the
      quadriceps, using a portable dynamometer. Under stabilized conditions, patients, sitting with
      knees flexed at 10, 60 and 90 degrees (measured by a goniometer), were asked to extend the
      legs as far as they could. Three attempts were conducted and the mean value was obtained.
      Physical activity was measured using the Western Ontario and McMaster Universities
      Osteoarthritis questionnaire, which is self-administered and measures pain, stiff joints, and
      physical activity. Increased scores suggest decreased activity.

      In this study, all patients had osteoarthritis of both knees, and in every patient both knees
      were treated with the allocated treatment.

      Participants in the Group I received Diadynamic currents associated to Exercise while the
      Group II received only exercises three times a week for 8 weeks following initial assessment.

      The group I, Diadynamic currents was performed with the following parameters: application of
      the two-phase current and then the long-term one. Each current was applied for 4 minutes on
      the medial and lateral sides of the knee.

      All patients followed the same training program (Table 1). The intervention was divided into
      Phase-1, Phase-2 and Phase-3 during eight weeks with three sessions a week. Each session
      lasted 45 minutes:

        -  10 minutes warming-up (treadmill, ergometer bike or rowing machine);

        -  30 minutes 2-3 sets with Phase-1, Phase-2 and Phase-3;

        -  5 minutes stretching (hamstrings, quadriceps, adductors, and gastrocmenius).
           Participants were instructed not to use analgesic medications other than paracetamol
           (500 mg/day) or anti-inflammatory drugs during the study, and not to perform any other
           type of physical exercise in addition to the exercise performed during the study.

      After describing the data, the hypothesis of normality of continuous variables was tested
      using the Shapiro-Wilk test. The age, weight, height and BMI of volunteers between groups
      were compared using Student's t-test for independent samples. To investigate the effect of
      the treatment on the pre and post evaluation, as well as the interaction of this effect
      between the groups, the General Linear Models with mixed design (evaluations x groups) were
      applied. To analyze the effects of the interactions, Tukey's Post Hoc tests were performed
      considering an alpha error of 5%. All analyzes were performed using the statistical program R
      version 3.1.3 using the R Commander graphical interface.
    

Intervention name(s): Group that received aplication of Diadynamic currents associated to Exercise during eight weeks with three sessions a week; Group that received exercise during eight weeks with three sessions a week
Intervention type(s): Procedure; Other
Intervention description(s): Diadynamic currents was performed followed by exercises (divided into Phase-1, Phase-2 and Phase-3 during eight weeks with three sessions a week).; The intervention was divided into Phase-1, Phase-2 and Phase-3 during eight weeks with three sessions a week. Each session lasted 45 minutes.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants were randomly allocated to a Group I (diadynamic currents associated to Exercise; n=30, 60 knees) and Group II (exercises group; n=30, 60 knees) were treated 3 times a week for 8 weeks.
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: PAIN; Electric Stimulation Therapy; Exercise Therapy