Maximum isometric torque at individually-adjusted joint angles exceeds eccentric and concentric torque in lower extremity joint actions

Abstract

Background Previous research indicates the high relevance of optimal joint angles for individual isometric strength assessment. The objective was to compare lower limb peak isometric muscle strength abilities at the strongest joint angles with those of dynamic contractions in healthy young adults. Methods Eighteen young male adults performed maximum concentric, isometric, and eccentric contractions of the ankle, knee, and hip flexors and extensors, and hip adductors and abductors in a randomized sequence on an isokinetic dynamometer (ISOMED 2000). Angular velocity was set at 60°/s. The peak of concentric contraction torque curves was used to define optimal joint angles best suited to generate maximum torque during isometric contractions. Maximum voluntary contraction torque of all contraction conditions was adjusted for limb weight and analyzed via a generalized linear mixed gamma regression model (GLMM). Results The gamma GLMM revealed strongly significant effects for all three categorical covariates (contraction types, muscle group, and test order) ($$p < 2 \times 10^{ - 16}$$ p < 2 × 10 - 16 ). Eccentric contraction increases the muscle torque ($$\hat{\beta }_{k} = 0.147$$ β ^ k = 0.147 ) compared to concentric contraction, and isometric contraction even more ($$\hat{\beta }_{k} = 0.258$$ β ^ k = 0.258 ). A moderate individual-specific variation was found (random effects standard deviation $$\sigma_{b} = 0.093$$ σ b = 0.093 ). Conclusion The results support the importance of optimal joint angles for isometric maximum strength assessment. When such conditions are given, isometric contractions can produce higher muscle torques than eccentric contractions in the lower body.

Examining the Link between Isokinetic Strength Metrics and Ball Speed in Women’s Soccer

“…The relationships between isometric and eccentric contractions of players' generated strength and ball speed were found to be non-significant. Previous studies have reported high strength torque production during isometric and eccentric contractions [56]. Additionally, it has been noted that immediately after isometric, concentric, and eccentric exercises with the same torque-time integral, similar neuromuscular fatigue is induced.…”

Strength and Power-Related Measures in Assessing Core Muscle Performance in Sport and Rehabilitation

“…For instance, maximum torques of the lower body differ significantly between contraction types, and this may be specific to the joint action, muscle groups used and the context of the testing ( Stotz et al, 2022 ). Maximum isometric torque can exceed eccentric and concentric torque in lower extremity joint actions when joint angles are individually adjusted ( Stotz et al, 2022 ). The knee and hip angles of 141° and 124° respectively used for MVC assessment of the back muscles correspond to the portion of the clean lift where the highest power is produced ( Garhammer, 1993 ).…”

“…However, it may also depends on joint angles used during isometric maximum strength assessment. For instance, maximum torques of the lower body differ significantly between contraction types, and this may be specific to the joint action, muscle groups used and the context of the testing ( Stotz et al, 2022 ). Maximum isometric torque can exceed eccentric and concentric torque in lower extremity joint actions when joint angles are individually adjusted ( Stotz et al, 2022 ).…”

Which trunk muscle parameter is the best predictor for physical function in older adults?

“…Similar postural sway measurements were carried out across studies and the main difference to our study is the application of isometric strength measures, while we used isokinetic strength measures. Torque of isometric measurements is highly dependent on the tested joint angle and varies between individuals [ 49 ]. Therefore, we opted for an isokinetic approach which is not dependent on the testing position.…”