Upon reaching this position and hearing the audible signal via th

Upon reaching this position and hearing the audible signal via the FitroDyne Premium device (Fitro, Slovakia), the subjects were required to lift the load with maximal speed. The subjects were not instructed to more info explode off the bench surface or throw the barbell. A three-minute rest was given between each lift. Three trials with each load were collected. The mean of the three trials was accepted for further analysis. Experimental Setup Two force plates (Kistler 9281CA and 9286AA, Switzerland) embedded in the floor and positioned below the bench, sampling at 988 Hz, were used to measure contact forces between the bench and ground during the lift. Three-dimensional upper extremities kinematic data during the bench press were collected at 247 Hz using a seven camera motion capture system (Qualisys Oqus, Sweden).

Data from the force plates and the cameras were collected simultaneously. The linear position transducer device (FitroDyne Premium, Slovakia) signaled using a sound that the subject could hear throughout the trial and which changed when the downward movement switched to the upward phase of the movement. Power testing was performed using free weight form techniques (Figure 1). Figure 1 Experimental setup of range of motion, force and velocity measurements during bench press exercises. The bench stands on the force plates. FitroDyne Premium device is connected to the barbell. Infra-red cameras layout and focus on the area of movement. … Data Analysis Power (W) was calculated as the product of vertical force (N) and vertical velocity (m?s?1) of the center of gravity (COG of system upper extremity segments and barbell).

The velocity of the center of gravity (m?s?1) was the necessary parameter derived from the visual 3D software. Marker data were processed using Visual 3D software (C-motion, Rockville, MD, USA). All upper extremity segments with the exception of hands were modeled as a frustum of right circular cones whilst the barbell was modeled as a cylinder. The vertical force (N) was obtained as the sum of two vertical ground reaction force (N) signals from two force plates and the weight of the upper extremities (N). The weight of the upper extremities (N) was calculated as a product of mass of the upper extremities (kg) and gravity acceleration (m?s?2). The power (W) for each load on each lift was determined.

We analyzed the part of the motion which showed positive power output (W). By differentiating the velocity Drug_discovery (m?s?1) of the center of gravity, the acceleration and deceleration parts of the upward part of the lift were determined (Jandacka & Vaverka 2008) (Figure 2). Thus the mean power (W) for each load (% of one repetition maximum) and lift was determined from the complete positive power movement and from the acceleration phase of the movement as well. Maximum power output (W) was the absolute maximum for all loads. We neglected the horizontal power which was negligibly small for all loads.

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