Effects of whole-body vibration exercise on muscular strength and power, functional mobility and self-reported knee function in middle-aged and older Japanese women with knee pain

Background: Whole-body vibration training using vertical-vibration machines is called "acceleration training" (AT). The purpose of this study was to elucidate the effect of AT on lower-limb muscular strength and power, functional mobility and self-reported knee function in middle-aged and older Japanese women with knee pain. Methods: Thirty-eight middle-aged and older Japanese women (aged 50-73 years) with knee pain were divided into two groups: (1) the AT group (n = 29) engaged in AT three times per week for eight weeks, and (2) the control group (C group, n = 9). The AT program consisted of flexibility training, strength training of mainly the quadriceps and surrounding muscles and cool-down exercises. The C group was encouraged to perform the same or similar exercises at home without vibratory stimulus. We evaluated knee strength and power, functional mobility (timed up and go: TUG) and self-reported knee function (Japanese Knee Osteoarthritis Measure: JKOM). Results: No one in the AT group dropped out during the program. All JKOM categories except degree of pain improved significantly post intervention indicating improved knee function, and TUG was significantly shorter in these participants. All knee strength and power parameters except isometric knee extension peak torque improved significantly. The degree of change in JKOM total score and TUG was significantly different between the two groups. Conclusion: Vibratory stimulus during an eight week AT programme can promote participation and safely improve functional mobility and self-reported knee function better than exercise without vibratory stimulus in middle-aged and older Japanese women with knee pain. Level of evidence: level 2. (C) 2014 Elsevier B.V. All rights reserved.