Senior Projects

Background and objectives: Vertical jumping constitutes an integral component of explosive performance in numerous athletic activities. Plyometric exercises were initially utilized to enhance sport performance. Plyometrics are training techniques used by athletes in all types of sports to increase strength and explosiveness. The main purpose of this study is to determine the effect of 6 weeks of ground plyometric training of low-moderate intensity (counter movement/jump to box/ box drills to rings) on both vertical jump and Quadriceps leg strength for both right and left muscles. Methods: A cohort study of 36 subjects were randomly chosen from department of physical therapy from Beirut Arab University according to their level of activity (sedentary-active-highly active), level of smoker (non smoker- occasional- heavy smokers), height, weight, BMI (18-33), measurements of upper limb length, leg length and femur length (both sides). Training was performed 3 times per week. The vertical jump height and Quadriceps muscle performance were measured before training, after three weeks of training and after 6 weeks of training, using Vertec to measure the mean of the Vertical Jump Height and Isometric Dynamometer to measure the mean Quadriceps muscle strength for both right and left sides. Results: Anova studied showed that status of smoking status, level of activity, and height of the trainee had no effect, neither on vertical jump height nor on Quadriceps muscle strength of (p>0.05) . In addition the results showed correlations significance between each of BMI, weight, right femur length, right leg length, and right upper limb length with the Quadriceps muscle strength. Whereas the difference between the three measured means of Quadriceps strength showed (p>0.05) indicating of no significance difference. While for the Vertical Jump Height measured means indicated P value of 0.006 < 0.05, revealing a significance difference. Conclusions: There is no significance that plyometric training with low and moderate intensities increases Quadriceps leg strength, while a great significance revealed the effect of 6 weeks of low-moderate ground plyometric training on vertical jump height.