Vibration training is a novel strength training method that has gained popularity in the last five years. However, current findings on vibration training are contradictory about whether vibration training is an effective training method for strength and power development. A critical review of the relevant literature reveals that vibration training effect may be dependent on a number o f factors, in particular vibration characteristics (vibration amplitude and frequency) and exercise protocol (type of exercise and exercise intensity). However, there is a lack of study of many of these factors. The aim of this study is to investigate the influence o f these factors on the acute effect o f vibration training on neuromuscular performance. Methods: A portable muscle-tendon vibrator with variable vibration amplitude (0.2 to 2 mm) and frequency (30 to 200 Hz) capacity was developed in the thesis. The vibration is produced by a number of rotating eccentric masses. The vibrator is strapped to the muscle tendon during the strength training exercise. Neuromuscular performance was assessed during strength training exercise by examining EMG and various mechanical outputs. The mechanical outputs included: angular velocity, moment and power assessed in terms of peak, average, rate of development and initial (first 100 ms) measures. Findings: Study 1: The vibration amplitude on the vibrator and the muscle was affected by the eccentric mass, with a large eccentric mass (ems-II) producing significantly greater amplitude (1.2 mm) than the small eccentric mass (0.5 mm) (ems-I) (p<0.05). The vibration frequency on the vibrator and the muscle was not effected by the eccentric mass size (p>0.05). The transmissibility o f vibration amplitude from the vibrator to the muscle was significantly higher with ems-I (p<0.05). The transmissibility of vibration peak frequency to the muscle was not affected by the eccentric mass (p>0.05), and was 100%. Vibration induced a significant increase in EMGrms of the biceps in sub-maximal isometric elbow flexion (p<0.05), with ems-II producing greater increase than ems-I (0.053 vs. 0.026 mV, p<0.05). All of the above results for amplitude, frequency, transmissibility and EMG response were not significantly effected by test day, joint angle or strapping force (p>0.05), indicating the repeatability of the vibration load under various operational conditions. Study 2 : The vibration peak frequency of the vibrator was determined only by the motor rotating speed (p<0.05). The vibration amplitude of the vibrator was determined by both the eccentric mass and the motor rotating speed (p<0.05). The transmissibility of the vibration amplitude to the muscle was affected by both the eccentric mass and motor speed of the vibrator (p<0.05). The higher the vibration amplitude (eccentric mass) and vibration frequency (motor rotating speed) on the vibrator, the lower the transmissibility of vibration amplitude to the muscle (p<0.05). The transmissibility of peak frequency was 100%, and was not affected by the eccentric mass and motor rotating speed (p>0.05). Vibration induced a significant increase in EMGrms of the biceps in sub-maximal isomctfic ClbOW flexion (p^Q.QS), with the greatest increase of EMGrms being induced by vibration with a frequency of 65 Hz and an amplitude of 1.2 mm (p<0.05). The above amplitude, frequency,transmissibility and EMG results were not significantly effected by joint angle (p>0 05). Study 3 Vibration training induced enhancements m EMGrms o f the vastus lateralis (VL) and vastus medialis (VM) during sub-maximal isometric extension o f the knee (p<0 05), but not o f the rectus femons (RF) (p>0 05) Resistance load had a significant effect on the enhancement, with the greater load (20% 1RM) producing a significantly higher EMGrms than the smaller load (10% 1RM), on both the VL (0 049 vs 0 038 mV, p<0 05) and VM (0 069 vs 0 049, p<0 05). Study 4 During training, direct vibration did not enhance the mechanical (angular velocity, moment and power) and EMG output of a maximal isotonic bicep curl exercise (p>0 05) Similarly, after training there was no enhancement in the mechanical and EMG output when either the muscle was trained maximally or the muscle was rested (untrained) (p>0 05). Study 5 Direct vibration did not enhance the mechanical (angular velocity, moment and power) and EMG output of a ballistic knee extension exercise during and after training On the contrary, vibration significantly increased the time to peak power (4%, 10% and 16% in set 1, 2 and 3, respectively, p<0 05) and decreased EMGrms o f the RF (10%, 14% and 15% m set 1, 2 and 3, respectively, p<0 05) and EMGmpf of the VL (7% in set 2, p<0 05) during training, and decreased EMGrms of the RF measured 15 minutes (16%, p<0 05) and 10 minutes (15%, p<0 05) after training. Study 6 With both resistance loads (40% and 70% 1RM), direct vibration did not have an acute or acute residual facilitatory effect on the neuromuscular performance of a maximal isotonic bicep curl exercise (p>0 05). On the contrary, vibration significantly decreased mean power with the 70% 1RM load (16 8%, 13% and 18 5% in set 1, 2 and 3, respectively, p<0 05) and the initial power with both loads (19 5%, p<0 05). Conclusion: A portable muscle tendon vibrator has been successfully developed to allow investigation of the effect of vibration at different frequencies and amplitudes during sub-maximal and maximal isometric and isotonic contractions. The vibrator can produce the required vibration load consistently across different operational conditions. For sub-maximal isometnc contractions, vibration could induce a significant increase of EMG. The enhancement was greater with the increase of vibration amplitude (1 2 vs 0 5 mm) and frequency (100 and 65 Hz vs 30 Hz). In addition, the higher resistance load could induce greater EMG response to vibration training with sub-maximal isometnc contraction. For maximal isotonic contractions, vibration did not enhance neuromuscular performance, and in fact had a negative effect on some mechanical and EMG outputs both dunng and after training Vibration alone (with no exercise) had no significant acute residual effect on the mechanical and EMG outputs of maximal isotonic contractions. The neuromuscular measurements m this thesis are repeatable across different test days.