Metabolic power ( P met ) has been proposed as a tool to estimate the energetic demands of variable-speed locomotion typically seen in team sports. 1 From the outset, it should be stated that this model is not able to fully account for the physical demands of team-sport activity, 2 , 3 but nor
Ted Polglaze and Matthias W. Hoppe
Gianluca Vernillo, Adrien Mater, Gregory Doucende, Johan Cassirame, and Laurent Mourot
neither the self-optimizing capability nor the energetically optimal SF seems to be substantially affected by slope in a nonfatigued state, 3 graded running poses unique physiological and biomechanical challenges, 4 and has several fatigue-related intrinsic features. 5 Accordingly, whether a fatiguing
Richard Latzel, Olaf Hoos, Sebastian Stier, Sebastian Kaufmann, Volker Fresz, Dominik Reim, and Ralph Beneke
in direction and speed. 8 Although the BEST had been designed for testing match-related fitness, its energetic profile is not known. Therefore, the aim of this study was to provide a first metabolic profile of the BEST in junior elite basketball players. The metabolic profile was assessed by a
Sebastian Kaufmann, Olaf Hoos, Timo Kuehl, Thomas Tietz, Dominik Reim, Kai Fehske, Richard Latzel, and Ralph Beneke
the magnitude of ∼25 mmol·kg wetmuscle −1 . This estimate can be seen as a muscle energetic performance limit and is supported by biopsy measurements after intermittent high-intensity exercise. 28 , 29 Although the overall contribution of the anaerobic lactic energy system is rather low in both YYIR1
Rodrigo Zacca, Bruno Mezêncio, Flávio A. de Souza Castro, Fábio Y. Nakamura, David B. Pyne, João Paulo Vilas-Boas, and Ricardo J. Fernandes
and not evaluated for wetsuits). 1 The use of wetsuits in OW swimming events is forbidden if water temperature is ≥20°C, optional if 18°C–20°C, and compulsory between 16°C and 18°C. 1 , 2 Improved biomechanics and energetics have already been reported when swimming with wetsuit. 3 However
Sebastian Kaufmann, Olaf Hoos, Aaron Beck, Fabian Fueller, Richard Latzel, and Ralph Beneke
multiple SSC, probably induced by fast change of direction movements with rapid repetitive accelerations and decelerations, sprints, and/or jumps. So far, the metabolic profile of CJ30 is unknown. In order to compare the energetics of CJ30 and WAnT, we aimed at calculating the first metabolic profile for
Jonathan K. Holm, Jonas Contakos, Sang-Wook Lee, and John Jang
This study investigated the energetics of the human ankle during the stance phase of downhill walking with the goal of modeling ankle behavior with a passive spring and damper mechanism. Kinematic and kinetic data were collected on eight male participants while walking down a ramp with inclination varying from 0° to 8°. The ankle joint moment in the sagittal plane was calculated using inverse dynamics. Mechanical energy injected or dissipated at the ankle joint was computed by integrating the power across the duration of the stance phase. The net mechanical energy of the ankle was approximately zero for level walking and monotonically decreased (i.e., became increasingly negative) during downhill walking as the slope decreased. The indication is that the behavior of the ankle is energetically passive during downhill walking, playing a key role in dissipating energy from one step to the next. A passive mechanical model consisting of a pin joint coupled with a revolute spring and damper was fit to the ankle torque and its parameters were estimated for each downhill slope using linear regression. The passive model demonstrated good agreement with actual ankle dynamics as indicated by low root-mean-square error values. These results indicate the stance phase behavior of the human ankle during downhill walking may be effectively duplicated by a passive mechanism with appropriately selected spring and damping characteristics.
Mhairi K. MacLean and Daniel P. Ferris
biomechanical perspective, an exoskeleton that assists at one lower limb joint but not others should alter energetic cost differently depending on the locomotor task. A large majority of the total mechanical work performed by muscles during a step can be calculated as the summation of positive and negative
Tiago M. Barbosa, Mário Costa, Daniel A. Marinho, Joel Coelho, Marc Moreira, and António J. Silva
The aim was to develop a path-flow analysis model for young swimmers’ performance based on biomechanical and energetic parameters, using structural equation modeling. Thirty-eight male young swimmers served as subjects. Performance was assessed by the 200-m freestyle event. For biomechanical assessment the stroke length, the stroke frequency and the swimming velocity were analyzed. Energetics assessment included the critical velocity, the stroke index and the propulsive efficiency. The confirmatory model explained 79% of swimming performance after deleting the stroke index-performance path, which was nonsignificant (SRMR = 0.06). As a conclusion, the model is appropriate to explain performance in young swimmers.
Elisa S. Arch and Bretta L. Fylstra
The large, late-stance energy generated by the ankle is believed to be critical during gait. However, the distal foot absorbs/dissipates a considerable amount of energy during the same phase. Thus, the energy generated by the combined ankle–foot system is more modest, which raises questions regarding the necessity of such a large ankle power and the interplay between foot and ankle energetics. This study aimed to evaluate our conservation of energy hypothesis, which predicted if distal foot energy absorption/dissipation was reduced, then less energy would be generated at the ankle and thus the same combined ankle–foot energetics would be achieved. Motion analysis data were collected as healthy subjects walked under 2 conditions (Shoes, Footplate). In the Footplate condition, the shoe was replaced with a customized, rigid footplate with a rocker profile. In support of the hypothesis, there was significantly less positive ankle and less negative distal foot work with footplate use, resulting in very similar combined ankle–foot work between conditions. These findings suggest that there is an interplay between the energy generated by the ankle and absorbed by the foot. This interplay should be considered when designing orthotic and prosthetic ankle–foot systems and rehabilitation programs for individuals with weakened ankle muscles.