EFFECT OF EXTERNAL APPLICATION OF SEMICONDUCTORS ON MOTOR PERFORMANCE: CASE STUDIES

INTRODUCTION AND PURPOSE In order to enhance motor performance, humans have utilized a variety of agents and/or techniques. External application of semiconductors has been currently advertised as a stimulus and as an enhancer of muscle performance. If the claim is correct, one could hypothesize that external application of semiconductors, such as germanium, may positively enhance motor performance. Discovery of a non invasive, effective and safe performance enhancer will be of definite value. Thus, the purpose of this study was to investigate the effects of external application of germanium on motor performance. METHODS Two motor tasks, vertical jumping and kicking, were investigated. An experienced kicker and a student participant in a University activity class participated in the kicking and jumping tasks, respectively. A NAC 400 High Speed Video Recording System was utilized to record ten kicks performed by the subject. For the first 5 kicks (condition A), the subject was wearing germanium imbedded cloth knee wraps (Goode Wraps, Reno, Nevada, USA.). For the next 5 kicks (condition B), the subject was wearing cloth knee wraps without germanium imbedded in them. Prior to videotaping each group of kicks, the subject sat quietly for 20 minutes and then exercised at the same level of intensity on a stationary bicycle ergometer for a period of five minutes. The same protocol was utilized during vertical jump data collection with the addition of a Kistler force plate to simultaneously collect force data and with the subject wearing ankle wraps and (Stromgren) shorts imbedded with germanium in addition to knee joint wraps. Jumping heights were calculated utilizing force plate data. All kicks and the best trial from each group of jumps (based on jump height) were digitized utilizing an Ariel Performance Analysis System (APAS). RESULTS AND CONCLUSION Kicking results showed that maximum ball velocity, knee joint angular velocity, and thigh and shank angular velocities at contact were larger in condition A than in condition B (26.5 d s , 802 deg/s, 382 deg/s, and 11 83 deg/s vs. 25.6 d s , 785 deg/s, 344 deg/s, and 1130 deg/s for conditions A and B, respectively). Paired t-tests, however, showed that the differences between the two conditions were not statistically significant (

EFFECT OF FORCE CHARACWRISTICS AND REACTION ABILITY ON VERTICAL JUMPING IN YOUNG BASKETBALL PLAYERS

INTRODUCTION AND PURPOSE A vast quantity of scientific literature exists on the mechanisms and determinants of jumping ability. Yet, the influence of a) the maximum isometric push-off force, b) the speed by which maximum push-off force is developed, and c) the reaction ability to drop jump on the effective use of horizontal and drop vertical velocities in vertical jumping has not been thoroughly investigated. It was, thus, the purpose of this study to investigate the relationship and influence of these parameters on vertical jumping in young basketball players. Nine young male basketball players (age: 13.34 yrs; height: 1.71m; weight: 60.2 Kg) were tested on: a) maximum isometric push-off force (F-); b) vertical countermovement jumps with (CMJw) and without (CMJw,) the use of the arms; c) vertical jump from a flexed hip, knee, and ankle joint position (SJ); d) drop vertical jumps from heights of 18 (DJ18), 36 (DJ,,), and 42 cm (DJ,,); e) vertical jumps with one step (CMJ,), and horizontal velocities of 1.5 (CMJ,), and 2.2 mlsec (CMJ,); and, f) vertical jumps with self-paced horizontal velocity with (CMJ,) and without (CMJ,,) the use of the arms. Two pairs of photo cells, and two 1-D dynamometers were used for data collection. RESULTS AND CONCLUSION T-test results showed no significant differences (

TEMPORAL CHARACTERISTICS OF THOMAS FLAIRS ON THE POMMEL AND FLOOR

To perform successfully on any apparatus, gymnasts must execute skills with creativity and virtuosity. Whereas creativity is demonstrated by introducing new skills, combining existing ones, or adapting skills to different apparatuses, virtuosity is expressed by executing skills with exceptional technique (Prassas et al. 2006). The Thomas Flairs (Fig. 1), originally introduced and performed on the pommel horse, have been adapted on other apparatuses including the floor. Understanding the timing of the different phases of the skill and what effect the different physical characteristics of the two apparatuses may impose on that timing, would be valuable to coaches and gymnasts seeking to improve performance, judges evaluating gymnastic routines, and scientists studying motor skills