Muscle Dynamics as the Result of Whole Body Vibration and Plyometrics.

摘要

BACKGROUND: Whole body (WBV) vibration and plyometrics are common training techniques which increase strength, blood flow, force and power. The effects these techniques have on sedentary population is unknown. It is our aim to assess the effectiveness of WBV and plyometrics on sedentary population.;SUBJECTS: Three groups of nine sedentary subjects were assigned to either the control group (C), jumping only group (J), or jumping with vibration group (JV).;METHODS AND PROCEDURES: Measurements included: jump height (Myotest or Vertec), velocity, force, blood lactates, gastrocnemius and quadriceps strength, and exertion (RPE). Subjects were measured at the first, seventh, and eighteenth visits. C group attended measurements only. J and JV groups performed jumping from a vibrating platform (turned off for J and on for JV) to a surface 7-1/2 inches higher for 3 bouts of 20 seconds. J and JV groups attended three times per week for six weeks. Vibration was set at 40 hertz and 2-4 mm of displacement. Level of significance was set at p<.05.;RESULTS: There were no significant differences among groups for change in force (p=.733), velocity (p=.862), Vertec height (p=.367), and myotest height (p=.647). There was a significant increase in Vertec height from initial to final measure (p=.04) for JV group. RPE was significantly higher in JV than in C group at initial, three weeks, and six weeks (p< .001/ .008/ .004 respectively). There were non-significant decreases in blood lactate response to exercise in the experimental groups over time: J (p=.895) and JV (p=.121). There was significant interaction between group and time on quadriceps strength (p=.02) and a significant change of quadriceps strength between JV and C groups over 6 weeks (p-.02). There was a significant increase of gastrocnemius strength in J group (p=.01) by week 6.;CONCLUSION: JV group increased jump height, strength of quadriceps and gastrocnemius and greater exertion than controls. WBV with plyometrics had no effect on force, velocity, blood lactates, or calculated jump height. Further studies using an external focus may be necessary to elicit velocity, force and jump height changes.;Key Words: WBV, Sedentary, Force, Velocity, Jumping, Exertion.