![]() For example, shot putters may improve their overhead shot throw performance however, this does not indicate which specific strength qualities (maximal strength, rate of force development, and time to peak force) have improved. Although it is evident that isoinertial tests (e.g., 1RM back squat, 1RM power clean) and field tests (e.g., 10-m sprint, repeat agility tests, standing long jump, and overhead shot throw) demonstrate greater external validity in their ability to monitor changes in dynamic movements ( 12,13,36), there are limitations to isoinertial and field tests that can be overcome by multijoint isometric testing ( 38). These problems have been addressed recently with multijoint isometric assessments, in which tasks are closed chain, and at specific joint angles to maximize force ( 10,20,28,29). In the past, the use of isometric tests to assess changes in dynamic performance was considered suboptimal, primarily because of the neural and mechanical differences between isometric and dynamic muscular actions ( 1,25,36). Previous research has established that the isometric squat is strongly related to performance on the 1-repetition maximum (1RM) barbell back squat ( 6,8,28). The isometric squat performed on a force platform has been used as a means of detecting changes in kinetic variables as a result of training ( 20,27,38–40). In conclusion, an isometric squat performed at 90° and 120° is a reliable testing measure that can provide a strong indication of changes in strength and explosiveness during training. These findings demonstrate a degree of joint angle specificity to dynamic tasks for rapid and peak isometric force production. Rate of force development at 90° and 120° exhibited weak to moderate correlations with 1RM squat ( r = 0.55, 0.43) and partial squat ( r = 0.32, 0.42), respectively. Impulse 250 milliseconds (IMP) at 90° and 120° exhibited moderate to strong correlations with 1RM squat ( r = 0.70, 0.58) and partial squat ( r = 0.73, 0.62), respectively. Pearson product-moment correlations indicated strong relationships between isometric peak force at 90° (IPF 90°) and 1RM squat ( r = 0.86), and IPF 120° and 1RM partial squat ( r = 0.79). Test-retest reliability was very good for all isometric measures (intraclass correlation coefficients > 0.90) however, rate of force development 250 milliseconds at 90° and 120° seemed to have a higher systematic error (relative technical error of measurement = 8.12%, 9.44%). wk −1 for 12 weeks and were tested on 1RM squat, 1RM partial squat, and isometric squat at 90° and 120° of knee flexion.Subjects (17 men, 1-repetition maximum : 148.2 ± 23.4 kg) performed squats 2 d ![]() Thus, the purpose of this study was to further examine the relationship between isometric squat kinetic variables and isoinertial strength measures. J Strength Cond Res 29(5): 1386–1392, 2015-The isometric squat has been used to detect changes in kinetic variables as a result of training however, controversy exists in its application to dynamic multijoint tasks. The use of the isometric squat as a measure of strength and explosiveness.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |