Randomization was performed in computer-generated, permuted blocks of 6 to 10, stratified according to the participating ICU. Treatment assignments and a five-digit reference number were placed in sealed, opaque envelopes, which were opened by the person responsible for the preparation of the trial-drug solutions. The solutions of norepinephrine or dopamine were prepared in vials or syringes according to the preference of the local ICU. Each vial or syringe was then labeled with its randomly allocated number. The doctors and nurses administering the drugs, as well as the local investigators and research personnel who collected data, were unaware of the treatment assignments. The trial was approved by the ethics committee at each participating center. Written informed consent was obtained from all patients or next of kin.
Though improving jumping technique may add a couple inches to an athlete's vertical jump, good landing technique is even more crucial. The landing is when almost every jumping-related injury occurs, not the jump itself. For this reason, athletes should spend a significant amount of time learning to land in a balanced position that distributes the impact of the jump equally across all joints of the lower body. This position should look almost identical to the take-off position.
variations: The vertical jump test can also be performed using a specialized apparatus called the Vertec. The procedure when using the Vertec is very similar to as described above. Jump height can also be measured using a jump mat which measures the displacement of the hips. To be accurate, you must ensure the feet land back on the mat with legs nearly fully extended. Vertical jump height can also be measured using a timing mat. The vertical jump test is usually performed with a counter movement, where there is bending of the knees immediately prior to the jump. The test can also be performed as a squat jump, starting from the position of knees being bent. Other test variations are to perform the test with no arm movement (one hand on hip, the other raised above the head) to isolate the leg muscles and reduce the effect of variations in coordination of the arm movements. The test can also be performed off one leg, with a step into the jump, or with a run-up off two feet or one foot, depending on the relevance to the sport involved. For more details see vertical jump technique.
Vertical jump measurements are used primarily in athletic circles to measure performance. The most common sports in which one's vertical jump is measured are track and field, netball, basketball, football, and volleyball, but many sports measure their players' vertical jumping ability during physical examinations. In addition, single and multiple vertical jumps are occasionally used to assess muscular strength and anaerobic power in athletes.