Senior Projects

Objective: To investigate whether electrical stimulation combined with whole body vibration is effective in improving quadriceps strength and vertical jump performance in healthy subjects. Design: Randomized clinical trials. Setting: Faculty of Health Sciences, Department of Physical Therapy, 5th floor. Subjects: forty medical faculty students, divided into two groups, participated in the study. Interventions: Group A (9 males, 11 females) received 5 minutes stationary bicycle warm up, 30 minutes electrical stimulation with symmetrical biphasic faradic current (F: 80Hz; P.D: 100μs) plus 5minutes whole body vibration ( 1mins work, 1 min rest; F: 30Hz; amplitude: 8mm) protocol. Group B served as the control group. The five minutes of WBV was done during the 30 minutes electrical stimulation. This protocol was done for 6 weeks; 3 times/ week. The intensity of electrical stimulation was adjusted according to minimally palpable contraction in a comfortable position. Main outcome measures: Length measurements were done for volunteers for upper and lower limbs in both right and left sides. Also, all subjects were tested (pre, during and post) for peak torque on push-pull dynamometer (right and left quadriceps). The mean peak torque of three repetitions produced was used for data analysis. For vertical jump performance, the explosive power of both legs was measured (pre, after 3 weeks, and post) using the self-made Vertical jump. The test consisted of three trials; the mean of them was recorded as the final result. Approximately one minute rest was allowed between trials The perceived discomfort experienced with electrical stimulation was quantified by the use of a visual analogue scale (VAS). Results: Statistically no significant increase in quadriceps strength was observed after training in group A compared to group B. The P value was greater than 0.05; while in fact vertical jump performance improves significantly after training. Conclusion: The combination between electrical stimulation and whole body vibration is not suitable for eliciting increases in quadriceps strength. On the other hand, it can be used for gaining improvements in vertical jump performance.