AcknowledgementsWe are very grateful to the athletes of the Escola do Movimento Track and Field club for their involvement in the study. The authors declare that they have no conflict of interest.
Movement velocity as a measure of exercise intensity in three lower limb exercisesMovement strength velocity and intensity KEY WORDS: Resistance training, movement velocity, strength.
ABSTRACTThe purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: Leg Press, Full Squat, and Half Squat. The percentage of one Repetition Maximum (%1RM) has typically been used as the main parameter to control resistance training, however more recent research has proposed movement velocity as an alternative.Fifteen participants performed a load progression with a range of loads until they reached their one repetition maximum (1RM). Maximum instantaneous velocity (Vmax) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed.For all exercises, a strong relationship between Vmax and the %1RM was found: Leg Press (r 2 adj =0.96; 95% CI for slope is [-0.0244 Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise.
Apart from the rare malignant melanomas occurring in blue nevi, primary cutaneous malignant melanoma arises in 1 of 3 ways, regardless of the presence or absence of a pre‐existing nevus. These three types have been designated: 1. Malignant melanoma, invasive, with adjacent intra‐epidermal component of Hutchinson's melanotic freckle type; 2. Malignant melanoma, invasive, with adjacent intra‐epidermal component of superficial spreading type; and 3. Malignant melanoma, invasive, without adjacent intra‐epidermal component. Occasionally, both clinically and histologically, there may be difficulty in deciding whether a malignant melanoma belongs to category 1 or 2, but, in the majority of cases, these 2 types can be quite readily distinguished. In addition to recording the histogenetic mode of development of a malignant melanoma, a histologic system of reporting is recommended which includes mitotic activity, levels of invasion, and vascular involvement. There are other parameters such as the cell type, pigmentation, lymphocytic infiltrates, evidence of spontaneous regression, associated nevi, and solar changes in the dermis, all of which are of unknown significance. The recording of these features, which are clearly of interest for research purposes, is left to individual discretion. It is emphasized that all the usual macroscopic descriptions and measurements should continue to be recorded.
This study aims to comprehensively assess the accuracy and precision of five different devices and by incorporating a variety of analytical approaches for measuring countermovement jump height: Qualisys motion system; Force platform; Ergojump; an Accelerometer, and self-made Abalakow jump belt. Twenty-seven male and female physical education students (23.5 ± 3.8 years; height 170 ± 9.1 cm and body mass 69.1 ± 11.4 kg) performed three countermovement jumps simultaneously measured using five devices. The 3D measured displacement obtained through the Qualisys device was considered in this study as the reference value. The best accuracy (difference from 3D measured displacement) and precision (standard deviation of differences) for countermovement jump measurement was found using the Abalakow jump belt (0.8 ± 14.7 mm); followed by the Force platform when employing a double integration method (1.5 ± 13.9 mm) and a flight-time method employed using Qualisys motion system data (6.1 ± 17.1 mm). The least accuracy was obtained for the Ergojump (−72.9 mm) employing its analytical tools and then for the accelerometer and Force platform using flight time approximations (−52.8 mm and −45.3 mm, respectively). The worst precision (±122.7 mm) was obtained through double integration of accelerometer acceleration data. This study demonstrated that jump height measurement accuracy is both device and analytical-approach-dependent and that accuracy and precision in jump height measurement are achievable with simple, inexpensive equipment such as the Abalakow jump belt.
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