The increase in weight-lifting performance after resistance training is greater than the increase seen in maximal voluntary isometric contraction (MVC). This discrepancy has been attributed to learning and coordination. The purpose of the present study was to look into the contribution of joint angle specificity, and the specificity of the movement at various speeds in explaining the disproportionate increase in weightlifting strength compared to isometric strength. Eighteen participants completed the study. The quadriceps muscle group of each individual was trained unilaterally on a leg extension machine. Participants performed four sets of ten lifts at a steady pace. A load of 80% of the maximum load (1RM) was prescribed. The MVC of the quadriceps was measured on a strength-testing chair. The length-tension relationship was measured isometrically at 600, 750, 900, and 1050 of knee flexion. Measurement of isokinetic strength at velocities of 450/s, 1800/s and 300/s were made. All measurements were made before and after the training. The eight weeks training resulted in a 33% increased in weights lifted (p < 0.05) that was significantly greater than the gain in isometric MVC (6%). Significant gains in isometric strength were seen at all the joint angle but with no evidence of length specificity. Although there were significant gains in strength at higher velocities, they were not sufficient to explain the increased weight-lifting performance and, in any case, similar gains were seen with the untrained leg where no improvement in weight-lifting
performance was seen. From the findings it is concluded that angle and velocity specificity could not fully account for the discrepancy between gains in weight-lifting performance compared to isometric strength.
The purpose of this study was to investigate the relationship between anthropometric and motor performance and to determine the contribution of combined anthropometric dimensions on motor performance. A total of 225 male (n = 138) and female (n = 87) Malaysian university athletes aged
between 18 and 28 years (M = 22.1, SD = 1.8) from 18 different team related sports and individual sports participated in this study. The subjects underwent anthropometric measurements (height, weight, BMI,% body fat, waist-hip ratio) and motor performance tests (grip strength - GS, back
strength - BS, 7 level sit-up - SU7, 10m sprint - S10, 30m sprint - S30, sit and reach - SR, trunk extension test - TE, SEMO agility test - SEMO, vertical jump - VJ, standing long jump - SLJ, reaction time (audio) - RTa, reaction time (visual) - RTv, bleep test - Bleep, leg strength - LS, stork test– ST, and push-ups - PU). Descriptive analysis showed that anthropometric and performance difference between sports reflected the needs and requirements of the sports. Multivariate Analysis of Covariance (MANCOVA) and multiple regression analysis showed that height, weight, BMI, % body fat, waist-hip ratio contributed positively or negatively on specific components of motor performance. Among male athletes, all anthropometric were found to be a significant contributor to strength, vertical jump, cardiovascular endurance, while among females, only % body fat and WHR contributed significantly to abdominal strength, vertical jump and trunk extension. Findings of the study suggested that anthropometric characteristics that contributed to motor performance should provide a scientific rationale in selecting and training of athletes.