Whole Body Vibration Induced Muscle Activity and Effect of the Changes in Length of Soleus Muscle and Angle of Ankle
Condition: Muscle Physiology
Study type: Interventional

Summary: 
      Previous studies reported that myoelectrical activity increased during whole body vibration
      (WBV). The investigators hypothesized that the change in soleus muscle length does not affect
      the whole body vibration induced soleus reflex muscle activity but the change in ankle angle
      affects the whole body induced soleus reflex muscle activity. The purpose of this study is to
      test this hypothesis.
    

Detailed description: 
      Eighteen healthy young adult men are planned to include in this study. Surface electrodes
      will be placed on the right soleus muscle's belly. The electrodes (10-mm in diameter,
      inter-electrode distance of 20 mm) were arranged in the direction of the muscle fibers. The
      skin overlying the muscle was shaved, light abrasion was applied, and the skin was cleaned
      using 70% alcohol.

      A piezo-electric accelerometer (LIS344ALH full-scale of ±6 g linear accelerometer, ECOPACK)
      will be placed on the achilles tendon and a force sensor (FC2331-0000-2000L Compression Load
      Sensor, France) will be placed under the right heel. All data will be recorded by PowerLab
      (data acquisition system, ADInstruments, Australia) device. The data were processed offline
      with a computer. All surface electromyography (SEMG) analyses were conducted using a software
      (LABCHART7 ver. 7.3.3; POWERLAB System, ADInstruments). All SEMG recordings were 80-500 Hz
      band-pass filtered. Root-mean-square values (RMS) were calculated from the filtered SEMG
      signal.

      WBV (PowerPlate Pro5) with high amplitude at 35 Hz will be applied. Participants were
      barefooted, and no sponge or foam was placed between the vibration platform and their feet.
      Participants will stand in different position with their knees locked during WBV. Their hips
      and knees were in a neutral position. Positions: Position-1: Upright standing on zero sloping
      vibration platform Position-2: Standing with 10 degrees ankle dorsiflexion on zero sloping
      vibration platform Position-3: Standing with 20 degrees ankle plantarflexion on zero sloping
      vibration platform Position-4: Upright standing on twenty degrees forward inclined vibration
      platform (angle angle will be 20 degrees ankle plantarflexion) Position-5: Leaning forward
      while standing on twenty degrees forward inclined vibration platform (angle angle will be
      neutral) Position-6: Upright standing on 10 degrees backward inclined vibration platform
      (angle angle will be 20 degrees ankle dorsiflexion) Position-7: Leaning backward while
      standing on 10 degrees backward inclined vibration platform (angle angle will be neutral)
      Sequence of the position will be random. Maximal voluntary contraction (MVC) was determined
      for each subject at the beginning of each position using magnitude of force between heel and
      vibration platform the when the subject attempted to activate the soleus muscle maximally.
      Then vibration exposure will be 30 seconds.

      The participants were instructed to relax their muscles throughout the recordings during WBV
      and were trained using electromyographic feedback to this end. WBV may impair the sense of
      balance and muscles may be activated to restore balance. To overcome this problem, the
      participants were familiarized with WBV with a 15 s trial session on the WBV device and they
      were asked to use the handles of the device to secure their balance.
    

Intervention name(s): vibration
Intervention type(s): Other
Intervention description(s): vibration will be applied at 35 Hz
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science