Repository logo
 

The Integration of Local Vibration Training Into Strength Protocols: The Acute Effects on Lower-body Isokinteic Strength and Power in Healthy, Active Females and Males

Files

Dissertation(2.05 MB)

Date

2023

Authors

Supervisor

Uthoff, Aaron
Cronin, John
Jones, Dianne

Item type

Dissertation

Degree name

Master of Sport, Exercise and Health

Journal Title

Journal ISSN

Volume Title

Publisher

Auckland University of Technology

Abstract

Background: Vibration stimulation has the potential to benefit individuals in the areas of therapeutic rehabilitation and exercise performance, namely in improving the strength and power of musculature. Vibration stimulation has been proven to promote neurophysiological responses within the body, such as increasing circulation to certain areas of the body and improving muscle and tendon functioning thereafter. Recent advances in technology have allowed vibration stimulation to be localised through the utilisation of localised vibration devices that can be placed directly onto or strapped around a desired anatomical location e.g. the hamstrings muscle. Applying localised vibration into a progressive exercise protocol has proven beneficial for improving bone density, increasing flexibility, improving strength and power outcomes in musculature, and enhanced ability to apply force across a range of muscle contractions. However, the best practice for integrating localised vibration into clinical, strength and power performance programs is yet to be established. The neurophysiological function of a muscle differs depending on whether it is lengthening (eccentric contraction), shortening (concentric contraction), or being held at a constant length (isometric contraction). Isometric muscle contractions are the most common actions prescribed during clinical, applied rehabilitation and strength and power programs because they are safe and allow relatively high forces to be applied. Currently there is a dearth of information within the literature on whether localised vibration during isometric muscle contractions has an acute effect on the isokinetic strength and power once the vibration stimulus has been removed. Therefore, an exploration of this information may shed light on the utility of using localised vibration training to induce strength and power adaptations to muscle. Aims: This dissertation firstly aimed to review the current literature on acute localised vibration effects on strength and power of various musculature. The second aim of this dissertation was to then integrate this information into an experimental protocol to investigate the acute effect of localised vibration stimulation during an isometric strength exercise on the subsequent isokinetic strength of the hamstrings and quadriceps muscles once the localised vibration was removed from the hamstrings muscles. Methods: Firstly, a systematic review was carried out to investigate the current literature on the acute effects of localised vibration on strength and power outcomes, in which 23 published articles were critiqued from four different databases . Secondly a random cross-over trial was conducted with 16 healthy participants (7 = female; 9 = male); aged: 24.6 ± 4.52 years, height: 172.8 ± 8.83 m, weight: 74.3 ± 14.5 kg. Participants volunteered to take part in an isokinetic strength test protocol with localised vibration applied during an isometric hamstring exercise; the subsequent eccentric and concentric strength of both the hamstrings and quadriceps was then tested once the vibration stimulation was removed. The peak torque, angle of peak torque, mean power and time to peak torque were measured for both the flexors and extensors. A repeated measures ANOVA with post hoc contrasts was employed to analyse data for statistical difference. Results: Overall the findings from the literature review revealed that acute localised vibration has a positive effect on both strength and power, with different vibratory settings having a different effect on both. The review revealed that higher frequencies (> 100 Hz), lower amplitudes (< 5mm) and longer durations (30 minutes) of vibration stimulation effected muscular strength the most, whereas lower frequencies (< 100 Hz), higher amplitudes (≥ 6mm) and shorter durations (< 1 minute) had more of an effect on muscular power outcomes. The randomised cross-over trial resulted in no statistically significant differences in peak torque, angle of peak torque, mean power and time to peak torque of both the extensors and flexors, between and within vibration and non-vibration groups. Conclusion: Acute localised vibration does have a positive effect on both muscular strength and power when the vibratory stimulus is placed onto or around the desired muscle when the appropriate loading protocol is used. However, the exact loading parameters for both strength and power are not exclusively defined and thus far ranges of effective stimulus (frequency, amplitude and duration) have been determined for both strength and power; nonetheless the literature review holds critical importance for the future application within the field. It can also be determined that one bout of localised vibration applied during an isometric hamstring exercise for ~ 8 – 12 minutes does not have an effect on the subsequent isokinetic strength of the hamstrings and quadriceps muscles. This was most likely due to a too low frequency and/or amplitude utilised for the particular muscle groups involved.

Description

Keywords

vibration, vibration stimulation, local vibration, localised vibration, muscular strength, muscular power

Source

DOI

Publisher's version

Rights statement

Permanent link

http://hdl.handle.net/10292/18836

Collections

Masters Dissertations