Background: Whole-body vibration (WBV) has been proposed as a viable alternative, or adjuvant to exercise for power development in athletes. More recently individualized frequency (I-Freq) has been introduced with the notion that individuals may elicit a greater reflex response to different levels (Hz) of vibration. Purpose: The aim of the study was to evaluate acute WBV as a feasible intervention to increase power in trained cyclists. Additionally, to evaluate the efficacy of utilizing I-Freq as an alternative to 30Hz, a common frequency seen in the literature. Methods: Twelve highly-trained, competitive male cyclists (age= 29.9 yrs ± SD 10.0; body height=175.4 cm ± SD 7.8; body mass= 77.3 kg ± SD 13.9) free of musculoskeletal injury or pathology participated in the study. The Wingate test for anaerobic power was administered on three occasions following a control of no vibration, 30 Hz, and I-freq. Measures of peak power (PP), average power (AP) and rate of fatigue were recorded and compared to the vibratory conditions using separate RM-ANOVA’s. Results: PP, AP, and rate of fatigue were not significantly impacted by 30 Hz and I-Freq vibration interventions (p > 0.05). Conclusion: Acute WBV using the parameters of the present study may not have been practical to elicit an increase in power as potential changes in the highly trained population may have been muted as a function of training status. / School of Physical Education, Sport, and Exercise Science

Preliminary normative standards are a tool clinical exercise specialists and health fitness instructors can use when interpreting muscular strength testing results. However, a challenge for professionals is evaluating an individual's one-repetition maximum (IRM) and relating that to others of the same age and gender, because there are no preliminary normative standards for 1RMs available when testing via free-weights and machines.This study conducted at Ball State University, Adult Physical Fitness Laboratory, examined results of muscular strength testing in order to obtain the normative muscular strength of adults. The purpose was to develop preliminary normative standards for strength of adults and to compare the 1RM weight an individual lifts between free-weights, Paramount, and Cybex machines. Seventy-nine healthy men and women between 18 and 79 years of age participated in the study. Subjects were tested on free weights, Paramount, and Cybex machines.Test results revealed preliminary normative standards for 1RM on free weights. Individuals were categorized in three age groups for the free-weight bench press and the Cybex (free-weight) Leg Press. The 18-23 year olds obtained a IRM mean (± Standard Deviation (SD)) of 200.6 + 32.8 lbs and 83.6 ± 18.5 lbs for men and women, respectively, for the free-weight bench press. The 43-59 year olds obtained a 1RM mean of 149.2 ± 41.8 lbs and 71.3 ± 8.6 lbs and the 60-79 year olds had a 1RM mean of 119.5 + 30.0 Ibs and 61.6 ± 15.6 lbs for men and women, respectively, for the free-weight bench press. The 18-23 year olds obtained a 1RM Cybex (free-weight) leg press mean of 484.9 + 58.0 lbs and 234.3 ± 67.5 lbs for men and women, respectively. The 43-59 year olds were able to obtain 1RM means of 444.4 + 84.9 lbs and 254.5 ± 51.7 lbs and the older subjects (60-79 years old) were able to obtain 1RM mean of 390.7 ± 98.6 lbs and 230.3 ± 76.6 lbs for men and women, respectively. Results were also documented in relative values by the amount of weight pushed divided by body weight for better comparison of individuals. Subjects generally lifted more weight on the Cybex (free-weight) leg press compared to the Cybex (machine) leg press. All subjects (N=79) had a mean and standard deviation of 294.9 + 87.7 lbs for the Cybex (machine) leg press (1RMs) and 343.4 ± 123.4 lbs on the Cybex (free-weight) leg press (1RMs). There was a significant difference between the Cybex (free-weight) leg press and the Cybex leg press (p<.001). The correlation for these two types of lifts was r=0.88. There was a significant difference between the free-weight bench press and the Paramount seated chest press (p<.001). The correlation for between the two types of lifts was r=0.93. / School of Physical Education, Sport, and Exercise Science

M.Tech. / Purpose: This study aims to determine whether adjusting the area of nerve root supply, or adjusting the attachment site of the latissimus dorsi muscle, will have an effect on the latissimus dorsi muscle and to which extend, with regards to strength and electromyographic (sEMG) activity. These effects were evaluated by measuring the latissimus dorsi .muscle strength using a Jamar dynamometer as well as sEMG readings of the latissimus dorsi muscle using a Neuro Trac ETS unit. Readings were taken prior to treatment on the first, third, and fifth consultations. Method: Forty five participants who met the inclusion criteria were stratified in number and gender between three groups of equal size (15 participants each). Group 1 received lower cervical adjustments (C5 - C7), group 2 received lower thoracic and lumbar adjustments (T6 - L5) and group 3 received detuned ultrasound therapy on the latissimus dorsi muscle. Group three served as the control group. Participants were treated four times out of a total of five sessions, over a maximum three week period Procedure: Objective data was collected at the beginning of the first and third session, as well as on the fifth consultation by means of a Jamar dynamometer and a Neuro Trac ETS unit in order to assess the functionality of the latissimus dorsi muscle. Analysis of collected data was performed by a statistician. Results: Statistically significant improvement in the dynamometry readings of both the experimental groups were noted when compared to that of the control group. The results of the sEMG activity were variable. Conclusion: The results show that adjusting the area of nerve root supply as well as adjusting the attachment site of the latissimus dorsi muscle are effective treatment protocols (as demonstrated statistically) in increasing strength of the latissimus dorsi muscle. The results suggest that adjusting the attachment site of the latissimus dorsi muscle is most effective in increasing the strength of the latissimus dorsi muscle. The results of the sEMG activity were variable and there were no evidence supporting the effectiveness of adjusting the area of nerve root supply versus adjusting the attachment site ofthe latissimus dorsi muscle on sEMG activity.

Muscle strength has been identified as an important contributor to athletic performance. Little attention however, has been paid to the specific relationship between peak isokinetic muscle strength and sprint starting performance. The aim of this study was to determine the influence of an adapted front knee angle, as determined by isokinetic assessment (the angle of peak torque production), on starting performance. Sixteen track sprinters, of elite-national or competitive-regional standard, were asked to perform eight sprints over 50m using four separate starting techniques. Technique 1 featured the athlete’s usual starting preferences while Techniques 2, 3 and 4 featured a standardised set of starting preferences with experimental modifications of the front knee angle in the “set” position. Isokinetic muscle strength was measured at slow (60°/s) and fast (240°/s) test speeds in order to determine the angle of peak torque production for concentric knee extension of each subject’s lead leg. Using one-way analysis of variance (ANOVA) and Post Hoc analysis (LSD), no significant differences (p>0.05) were observed between the experimental techniques for: block time, force-time measures during block time, sprint times, sprint velocity and acceleratio n measures at intervals up to 50m. Significant differences (p<0.05) were however observed between reaction times for the experimental techniques. Slower reaction times are most likely due to increased upper body pretension, resulting from the increased hip elevation seen for these techniques. The results indicate that increased hip elevation may have delayed the initiation of the relevant motor response required to affect an optimal sprint start. Technique 1 resulted in the shortest reaction times, shortest block times, fastest sprint times and greatest sprint velocities for all four techniques. This result was possibly due to the athlete’s experience with, and repeated use of, this technique. The experimental techniques therefore provided no added advantage over the subject’s preferred starting technique and did not significantly optimise sprint starting performance. The results show that modification of the front knee angle had no significant influence on sprint starting performance and sprint running ve locity or acceleration patterns up to 50m. Using Pearson’s Correlation Coefficient to determine the strongest correlations between isokinetic knee strength and sprint starting performance, analysis revealed that the strongest relationships were found between sprint starting performance expressed as acceleration and isokinetic knee strength expressed as relative peak torque and absolute peak torque. For Technique 1 the strongest correlation was found between acceleration (30m - 40m) and relative peak torque as measured at a test speed of 240°/s (r = 0.62). For the remaining experimental techniques, the strongest correlation was found between acceleration (10m - 20m) and relative peak torque as measured at a test speed of 60°/s (r = 0.53) for Technique 2, between acceleration (40m - 50m) and peak torque measured at a test speed of 60°/s (r = 0.72) for Technique 3, and between acceleration (0m - 5m) and peak torque as measured at a test speed of 240°/s (r = 0.71) for Technique 4. These results suggest that isokinetic muscle strength does not correlate strongly with sprint starting performance and that additional factors, such as neuromuscular organisation and muscle fibre typing, possibly make a greater contribution to optimal sprint starting performance.

The problem of the study was to determine the better predictors of sprint performance for male and female sprinters from selected leg power and isokinetic strength tests. Ten male and five female sprinters volunteered to be measured for vertical jump performance, anaerobic power and capacity, peak isokinetic torque at the hip, knee, and ankle joint, and sprint performance. A forward stepwise multiple regression analysis was performed to allow selection from all strength and power variables regressed on the dependent variables of 30 meters, 60 meters, and flying 30 meter sprints. This procedure allowed one to examine the contribution of each predictor variable to the regression model. Only the independent variables that elicited a regression equation significant at the .05 level were used in final regression models. The regression models developed for the males were: 30 meters (crouch start) = 6.115 - .083(anaerobic power) - .055(vertical jump) - .044(plantarflex 120"/s) - .022(knee flex 60'/s); 60 meters (crouch start) = 11.111 - .145(vertical jump) - .086 (anaerobic power) - .172(hip flex 300'/s) - .098(knee flex 60'/s); and 30 meters (flying start) = 4.295- .055(anaerobic power) - .312(knee flex 180'/s) - .090(hip flex 300'/s). The regression models for the women were different than the males and were: 30 meters (crouch start) = 9.530 - .346(vertical jump); 60 meters (crouch start) = 18.083- .686(vertical jump); and 30 meters (flying start) = 8.733- .352(vertical jump) . By knowledge of the variance of the better strength and power measures, 83.2% to 98.0% of the variance of the respective sprint tests were explained. The regression models could allow for the identification of potential sprint performers and the development of optimal sprint training program.

It is often difficult to optimize strength qualities in-season due to the conflicting influences of extensive skill practices combined with frequent game play of the competition schedule. The purpose of this study was to investigate the effects of two interventions on strength qualities and CMJ performance. Thirteen women volleyball players competing in NCAA Division I were tested before and after four weeks of an inseason strength training program with emphasis on heavy squatting (6-IORM), and then before and after three weeks of unloaded jump training. Dynamic squat strength, isometric squat strength, optimal power, CMJ, SJ and approach jump and reach were all tested before and after both cycles. There was a significant increase in both average 1RM squat strength (5%) and vertical jump (1%) following the strength cycle. Following the unloaded training, there was a significant increase in both peak power output (18%) and peak velocity (14%) in the CMJ. SJ performance significantly increased in both peak force (6%) and maximum height (10%). Throughout training, there were no decreases in maximal strength levels or post-test Vertec jump and reach. This study indicates that heavy squatting can improve vertical jump as well as 1RM squat despite a high volume in-season practice and competition schedule. Furthermore, unloaded training can improve the explosive qualities of athletes when used as a peaking cycle late in-season. Athletes maintained dynamic strength and jumping ability from pre-testing scores, while significantly increasing both peak velocity and power in the CMJ. / School of Physical Education

The purpose of this project is to review current literature on the mechanics and physiology of the vertical jump and to provide an understanding of the jump itself. The second purpose is to develop a step by step program to increase vertical jump from grade school through high school.