THE EFFECT OF TRAINING THROUGH PARTIAL RANGE OF MOTION

Abstract

INTRODUCTION: A full range of motion (ROM) is necessary for effective motor functioning. However, rehabilitation often commences with resistance training (RT) through partial ROM (PROM) in order to minimize the risk of re-injury. Studies on specificity of RT with regard to joint ROM based on isometric training and testing support the contention that strength gains are greater at the angular position at which RT is performed than at other positions. (Morrisey et al., 1995). Data regarding the specificity of PROM dynamic RT are scarce. The purpose of this study was to evaluate the effect of PROM isokinetic RT of the knee flexors on full ROM. METHODS: Four healthy subjects (Ss) trained their right knee flexors for 6 weeks with a Cybex II at 60°.sec-1 and a ROM of 40°-70°. Ss worked out 3 times per week performing 3 sets of 10 or 15 repetitions during the first 3 and the last 3 weeks respectively. Ss were instructed to perform both flexion and extension at maximal effort with an emphasis on the flexors. Pre- and post-training tests included 5 consecutive cycles of knee extension and flexion at 60°.sec-1 at a ROM of 5°-85°. The last 4 trials were used for analysis. The full ROM was divided into three sectors: 5°-40°, 40°-70°, 70°-85°. The size effect of the changes in strength was evaluated in two ways: a) The percentage changes relative to the pre training values, and b) The ratio between the mean gain and the pre training standard deviations (s.d). The work output of each sector was subjected to a two way ANOVA (4 trials by pre-post). Conclusions from this analysis are limited to the current sample. Further generalization requires a more extensive and representative sample. RESULTS: Results are displayed in Table 1. The gains in all sectors were significant (p<.05). CONCLUSION: The hypothesis of specific local effect of RT is rejected. RT through a PROM can elicit substantial strength improvement through full ROM.Training protocols based on PROM may be integrated into rehabilitation. REFERENCES: Morrisey, M. C., Harman, E. A., Johnson, M. J. (1995). Resistance Training Modes: Specificity and Effectiveness. Medicine and Science in Sports and Exercise 27, 648-660.