The relationship between passive stiffness and muscle power output: Influence of muscle CSA normalization
Muscle and Nerve
Introduction: We examined the relationshipbetween passive stiffness of posterior hip and thigh musclesand muscle power output before and after nor malization of pas-sive stiffness to muscle cross-sectional area (CSA). Methods:Pearson correlation coefficients (r) were used to assess the rela-tionships between the normalized and non-normalized slopes ofthe initial (phase 1) and final (phase 2) portions of the angle–tor-que curve and peak power output (Pmax). Results: A significantpositive relationship was observed between the non-normalizedslope of phase 1 and Pmax (r 5 0.723; P 0.001); however, nocorrelations were observed between the normalized slope ofphase 1 and Pmax (r 5 0.244; P 5 0.299) nor between Pmax andthe nor malized and non-normalized slopes of phase 2(r 520.159–0.418; P 5 0.067–0.504). Conclusions: The findingssuggest that muscle size, rather than stiffness, accounted for asignificant portion of the variance in muscle power output.
Palmer, T.B., Jenkins, N.D.M., Thompson, B.J., Smith, D.B. and Cramer, J.T. (2014). The relationship between passive stiffness and muscle power output: Influence of muscle CSA normalization. Muscle and Nerve, 49: 69-75.