Abstract
The aim of this study was to evaluate acute neuromuscular responses to local vibrations (LV) exposure through monitoring of imposed acceleration. Nineteen healthy males (age = 22.43 ± 2.76 years; body mass = 76.4 ± 12.94 kg; height = 175 ± 6.76 cm) performed an elbow flexion isometric exercise (Scott bench) in two experimental conditions: simple isometric exercise (Control - CON) and vibrating isometric exercise (Local Vibration - LV; Frequency = 20.01 ± 0.13, displacement = 2 - 5 mm). Protocols consisted of 5 maximal voluntary contractions of 12 seconds each and five minutes of recovery between series with (LV) or without vibration (CON). During the exercise, individuals were seated on the bench with the dominant arm resting on the bench support at an approximate angle of 45o between shoulder flexion and the torso. Strength parameters (Rate of Force Development - RFD, p = .030; Peak Force - PF, p = .027; and Fatigue Index - FI, p = .001) significantly increased in LV compared to CON. For EMG parameters, significant changes were only observed for highest value of increase rate of the EMG signal - RER (p = .041), median frequency of EMG signal between peak force and force at the end of the isometric action - MFFbic (p = .045) (agonist) and root mean square of EMG signal of peak force at the end of the isometric action - RMSFtric (p <.001) (antagonist). The addition of local vibrations in resistance training induced an increase in maximal strength, explosive strength and reduced the capacity to sustain strength generation.
Highlights
In sport sciences, the first studies involving vibration were conducted as an alternative to conventional methods of improving strength and flexibility (ISSURIN; TENENBAUN, 1999)
Protocols consisted of 5 maximal voluntary contractions of 12 seconds each and five minutes of recovery between series with (LV) or without vibration (CON)
Strength parameters (Rate of Force Development - Rate of force development (RFD), p = .030; Peak Force - peak force (PF), p = .027; and Fatigue Index - fatigue index (FI), p = .001) significantly increased in local vibrations (LV) compared to CON
Summary
The first studies involving vibration were conducted as an alternative to conventional methods of improving strength and flexibility (ISSURIN; TENENBAUN, 1999). It has been used to provide direct vibrations to a body segment. It is a vibration application system attached to cables and bars (ISSURIN; TENENBAUN, 1999; MORAS et al, 2009; FRIESENBICHLER; COZA; NIGG, 2012) or directly attached over the muscle tendon unit. These are classified as local vibration (LV, sinusoidal or random vibrations) devices (LUO; MCNAMARA; MORAN, 2008; LUO et al, 2009). Vibration has increasingly become importance over the past two decades in training programs, without a consensus on acute responses (RITTWEGER, 2010; FRISENBICHLER et al, 2012)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have