Noé Gomes Borges

VALIDITY OF TWO METHODS FOR ESTIMATION OF VERTICAL JUMP HEIGHT

Ache Dias, J, Dal Pupo, JD, Reis, DC, Borges, L, Santos, SG, Moro, ARP, and Borges Jr., NG. Validity of two methods for estimation of vertical jump height. J Strength Cond Res 25(7): 2034-2039, 2011—The objectives of this study were (a) to determine the concurrent validity of the flight time (FT) and double integration of vertical reaction force (DIF) methods in the estimation of vertical jump height with the video method (VID) as reference; (b) to verify the degree of agreement among the 3 methods; (c) to propose regression equations to predict the jump height using the FT and DIF. Twenty healthy male and female nonathlete college students participated in this study. The experiment involved positioning a contact mat (CTM) on the force platform (FP), with a video camera 3 m from the FP and perpendicular to the sagittal plane of the subject being assessed. Each participant performed 15 countermovement jumps with 60-second intervals between the trials. Significant differences were found between the jump height obtained by VID and the results with FT (p ≤ 0.01) and DIF (p ≤ 0.01), showing that the methods are not valid. Additionally, the DIF showed a greater degree of agreement with the reference method than the FT did, and both presented a systematic error. From the linear regression test was determined the prediction equations with a high degree of linearity between the methods VID vs. DIF (R2 = 0.988) and VID vs. FT (R2 = 0.979). Therefore, the prediction equations suggested may allow coaches to measure the vertical jump performance of athletes by the FT and DIF, using a CTM or an FP, which represents more practical and viable approaches in the sports field; comparisons can then be made with the results of other athletes evaluated by VID.

Effect of kinesio taping on jumping and balance in athletes: a crossover randomized controlled trial.

Abstract Nunes, GS, de Noronha, M, Cunha, HS, Ruschel, C, and Borges Jr, NG. Effect of Kinesio Taping on jumping and balance in athletes: A crossover randomized controlled trial. J Strength Cond Res 27(11): 3183–3189, 2013—The purpose of this crossover randomized controlled trial was to verify the effect of Kinesio Taping (KT) applied to the triceps surae with the aim to improve muscle performance during vertical jump (VJ), horizontal jump (HJ), and dynamic balance (DB) in healthy college athletes. The participants were 20 athletes (11 men) who competed in 4 different sports modalities (track and field, handball, volleyball, and soccer). Participants had a mean age of 22.3 ± 3.3 years, mean height of 1.74 ± 0.08 m, and mean body mass of 67.8 ± 10.1 kg. The intervention consisted of applying KT from the origin of the triceps surae to its insertion with the purpose of increasing muscle performance, and the placebo consisted of applying tape with nonelastic properties. There were no significant differences between KT and placebo conditions for height (m) in VJ (KT, 0.18 ± 0.06; placebo, 0.17 ± 0.06; p = 0.14), distance (m) in HJ (KT, 1.48 ± 0.3; placebo, 1.47 ± 0.3; p = 0.40), and DB in distance reached (m) in the star excursion balance test, normalized by lower limb length (anterior: KT, 90.0 ± 6.7; placebo, 89.5 ± 7.5; p = 0.56; posterolateral: KT, 92.5 ± 7.5; placebo, 93.2 ± 5.8; p = 0.52; posteromedial: KT, 98.3 ± 6.7; placebo, 98.7 ± 7.4; p = 0.69). The KT technique was not found to be useful in improving performance in some sports-related movements in healthy college athletes; therefore, KT applied to the triceps surae should not be considered by athletes when the sole reason of the application is to increase performance during jumping and balance.

Touchscreen device layout based on thumb comfort and precision

Thumb workspace analysis on touch-sensitive screen is used to assist designers in laying control buttons out on screen devices which are thought to be one-handed operated, e.g. mobile phones. Using inertial motion tracking system, kinematic variables as position and orientation for thumb link are obtained. Based on Euler angles, the motion angle for each thumb joint relative to its comfort position is calculated for a determined number of touch points on the screen. Additionally, touch points are associated to distal phalange link inclination which correspond to a tip thumb contact area that affect the touch precision. The collected data is used to calculate discomfort index and the contact area over the total thumb workspace and map them on the screen. Through calculations it is possible to conclude that some movements are performed easily (comforting) and/or precisely than others, e.g. finger vertical sliding is easier than horizontal one. Finally, in order to improve user comfort and precision, on the screen area, where control buttons should be shown. This analysis is applied, as a practical example, on a personal magazine smartphone application, in order to suggest a suitable design for the control buttons.