Impulse-Momentum: Functional Strength in the Context of Plyometric Training
Introduction Human strength is expressed at four levels physiologically: material strength of tissues, functional strength of the innervated musculotendinous unit, coordinated joint torques, and whole-body functional strength. Exercise programs aimed at improving strength should adhere to training specificity so that gains are achieved in an efficacious manner. Plyometric training can be used as a method for training the individual components of strength yet there is limited knowledge regarding which techniques might be most efficacious. This purpose of this study was to use the impulse-momentum relationship as a tool for comparing various techniques thought to improve specificity of training for functional strength. Methods Thirteen young adults performed jumping movements under four conditions: drop jump (emphasis on time, DJT), drop jump (emphasis on height, DJH), countermovement (CM), and squat jump (SJ). Differences in max force (BW), max power (kW), and propulsive impulse (BW*s) across conditions were assessed with an ANOVA. Results Differences in max force (DJH: 4.3, DJT: 5.6, CM: 2.5, SJ: 2.2) were observed for all comparisons (p<.05) with the exception of drop jumps. Differences in contact time (DJH: .34, DJT: .20, CM: .40, SJ: .51) were observed for all comparisons (p<.05) with the exception of SJ and DJH. Impulse (DJH: .55, DJT: .52, CM: .39, SJ: .39) was greater for the drop jumps compared to both SJ and CM (p<.05). Impulse was not different between drop jumps and between SJ and CM. Max power (DJH: 13.7, DJT: 16.5, CM: 11.5, SJ: 12.1) was greater for the drop jumps compared to the CM (p<.05). Conclusion The results suggest that DJT is the best plyometric exercise targeting passive force development while the others likely target high-velocity concentric force development. These results support the impulse-momentum relationship as a quantitative descriptor of functional strength and a tool to improve training specificity.
Louder, Talin, "Impulse-Momentum: Functional Strength in the Context of Plyometric Training" (2014). Graduate Research Symposium. Paper 71.