title: Does plantarflexion fatigue influence running economy response to advanced footwear technology?

authors: Bidois, Ben

subjects: running

abstract: Background: Previous research found an average 4.0% increase in running economy (RE) with runners wearing shoes with advanced footwear technology (AFT), however there is large inter-individual variability. Serval speculations have arisen to explain this variability, one being runners needing strong enough plantarflexion strength to fully benefit from AFT shoes. Therefore, this study will investigate the effects of plantarflexion fatigue on RE response to AFT shoes. Methods: Sixty-four participants (age, 33.5 ± 15.6 y; sex, 32 male, 32 female; VO2peak, 49.4 ± 8.3 mL/kg/min) completed two sessions. Session one collected demographic information and conducted an incremental VO2peak test on a treadmill. Session two included a plantarflexion power test and four RE tests in the Control and AFT shoe in a counterbalanced mirrored crossover design. These RE tests were followed by two rounds of a plantarflexion fatigue protocol, including pre-plantarflexion (PRE) and post-plantarflexion (POST) power tests. Each fatigue protocol was followed with a calf muscle fatigue and soreness visual analogue scales, along with a RE test in a counterbalanced shoe condition. Results: RE improved 4.0 to 4.3% in the AFT compared to the Control shoe. Plantarflexion fatigue induced 1.6 to 2.4% decline in RE. There were no significant interaction between shoe conditions and time (P > 0.691). Baseline plantarflexion power did not significantly correlate to AFT response (P > 0.132), nor did the change in plantarflexion power (PRE to POST) to the change in AFT response (PRE to POST) (P > 0.930). Conclusion: Overall, AFT improved RE while plantarflexion fatigue negatively affected RE. Isolated plantarflexion fatigue did not alter AFT response and plantarflexion power was not linked to AFT response, refuting speculations that runners need strong enough plantarflexion strength to fully benefit from AFT. Since isolated plantarflexion fatigue is not generalisable to running induced fatigue, investigating the effects of running induced fatigue on RE response to AFT is recommended.

text: Does plantarflexion fatigue influence running economy response to advanced footwear technology? Background: Previous research found an average 4.0% increase in running economy (RE) with runners wearing shoes with advanced footwear technology (AFT), however there is large inter-individual variability. Serval speculations have arisen to explain this variability, one being runners needing strong enough plantarflexion strength to fully benefit from AFT shoes. Therefore, this study will investigate the effects of plantarflexion fatigue on RE response to AFT shoes. Methods: Sixty-four participants (age, 33.5 ± 15.6 y; sex, 32 male, 32 female; VO2peak, 49.4 ± 8.3 mL/kg/min) completed two sessions. Session one collected demographic information and conducted an incremental VO2peak test on a treadmill. Session two included a plantarflexion power test and four RE tests in the Control and AFT shoe in a counterbalanced mirrored crossover design. These RE tests were followed by two rounds of a plantarflexion fatigue protocol, including pre-plantarflexion (PRE) and post-plantarflexion (POST) power tests. Each fatigue protocol was followed with a calf muscle fatigue and soreness visual analogue scales, along with a RE test in a counterbalanced shoe condition. Results: RE improved 4.0 to 4.3% in the AFT compared to the Control shoe. Plantarflexion fatigue induced 1.6 to 2.4% decline in RE. There were no significant interaction between shoe conditions and time (P > 0.691). Baseline plantarflexion power did not significantly correlate to AFT response (P > 0.132), nor did the change in plantarflexion power (PRE to POST) to the change in AFT response (PRE to POST) (P > 0.930). Conclusion: Overall, AFT improved RE while plantarflexion fatigue negatively affected RE. Isolated plantarflexion fatigue did not alter AFT response and plantarflexion power was not linked to AFT response, refuting speculations that runners need strong enough plantarflexion strength to fully benefit from AFT. Since isolated plantarflexion fatigue is not generalisable to running induced fatigue, investigating the effects of running induced fatigue on RE response to AFT is recommended.

year: 2025-06

title: A power sharing series power BJT array with isolated low voltage control for AC power control applications

authors: Kularatna, Nihal

subjects: AC power control

abstract: A technique for a continuously variable AC resistance using a series BJT array is presented. This array provides high power dissipation capability and uniform voltage and power distribution across the individual transistors. The array, controlled using a set of optoisolators to maintain the electrical isolation between the control circuits and the power stage, could be used as the basis to develop several useful techniques including a solid state AC regulator with comparable performance to the commonly used ferro-resonant systems; a linear AC electronic load suitable for testing UPS and other power conditioners; and, in other AC power control applications such as switching capacitors in AC resonant circuits.

text: A power sharing series power BJT array with isolated low voltage control for AC power control applications A technique for a continuously variable AC resistance using a series BJT array is presented. This array provides high power dissipation capability and uniform voltage and power distribution across the individual transistors. The array, controlled using a set of optoisolators to maintain the electrical isolation between the control circuits and the power stage, could be used as the basis to develop several useful techniques including a solid state AC regulator with comparable performance to the commonly used ferro-resonant systems; a linear AC electronic load suitable for testing UPS and other power conditioners; and, in other AC power control applications such as switching capacitors in AC resonant circuits.

year: 2006

title: Te Raupatu o Tauranga Moana : Volume 2, Documents relating to tribal history, confiscation and reallocation of Tauranga lands.

authors: Stokes, Evelyn

subjects: Tauranga lands

abstract: A report providing a historical and geographical overview on the confiscation of Tauranga lands. In two volumes, volume one comprises a narrative of the events described as the raupatu, the confiscation of lands in the Tauranga Moana tribal area under the New Zealand Settlements Act 1863.  Volume two is a collection of documents, edited and annotated which were compiled in support of the report. These documents include personal accounts, tribal history, land purchases, lands returned and crown transactions.

text: Te Raupatu o Tauranga Moana : Volume 2, Documents relating to tribal history, confiscation and reallocation of Tauranga lands. A report providing a historical and geographical overview on the confiscation of Tauranga lands. In two volumes, volume one comprises a narrative of the events described as the raupatu, the confiscation of lands in the Tauranga Moana tribal area under the New Zealand Settlements Act 1863.  Volume two is a collection of documents, edited and annotated which were compiled in support of the report. These documents include personal accounts, tribal history, land purchases, lands returned and crown transactions.

year: 1993