• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Moderators of fatigue: the complexity of interactions

Avin, Keith Gerard 01 May 2012 (has links)
Fatigue is a difficult phenomenon to study because the response can vary based upon task-specific (i.e. contraction type, intensity, position– vs. load-matching and muscle group/joint region) and subject-specific (i.e. sex and age) variables. Although numerous investigations have provided insight into muscle fatigue, further efforts were needed to better characterize the influence of age, sex, joint/muscle group, contraction type, and task complexity have upon fatigue. The primary purpose of this series of three studies was to identify and characterize the influences of potential moderating variables (i.e., sex, joint, age, contraction type, and task complexity) upon fatigue resistance during voluntary muscle contraction fatigue tasks through both empirical (systematic review and meta-analysis) and experimental methods. In general, women demonstrated either the same or better fatigue resistance than men (men never better), the sex advantage was joint specific not systematic, old men were more fatigue resistant than young men, task complexity was not an influential factor and fatigue differences were more readily apparent under isometric conditions. The inclusion of empirical and experimental methods helped clarify the driving factors of localized muscle fatigue. This in turn will better direct future study design and power for mechanistic, training and performance response studies.
2

Postactivation Potentiation in Human Ankle Muscles: The Effect of Age and Contraction Type

Lougheed, Kristen 09 1900 (has links)
This thesis is missing page 33 and 98. Neither of which are in the other thesis copies. -Digitization Centre / N/A / Thesis / Master of Science (MS)
3

The influence of training and athletic performance on the neural and mechanical determinants of muscular rate of force development

Tillin, Neale A. January 2011 (has links)
Neuromuscular explosive strength (defined as rate of force development; RFD) is considered important during explosive functional human movements; however this association has been poorly documented. It is also unclear how different variants of strength training may influence RFD and its neuromuscular determinants. Furthermore, RFD has typically been measured in isometric situations, but how it is influenced by the types of contraction (isometric, concentric, eccentric) is unknown. This thesis compared neuromuscular function in explosive power athletes (athletes) and untrained controls, and assessed the relationship between RFD in isometric squats with sprint and jump performance. The athletes achieved a greater RFD normalised to maximum strength (+74%) during the initial phase of explosive contractions, due to greater agonist activation (+71%) in this time. Furthermore, there were strong correlations (r2 = 0.39) between normalised RFD in the initial phase of explosive squats and sprint performance, and between later phase absolute explosive force and jump height (r2 = 0.37), confirming an association between explosive athletic performance and RFD. This thesis also assessed the differential effects of short-term (4 weeks) training for maximum vs. explosive strength, and whilst the former increased maximum strength (+20%) it had no effect on RFD. In contrast explosive strength training improved explosive force production over short (first 50 ms; +70%) and long (>50 ms; +15%) time periods, due to improved agonist activation (+65%) and maximum strength (+11%), respectively. Explosive strength training therefore appears to have greater functional benefits than maximum strength training. Finally, the influence of contraction type on RFD was assessed, and the results provided unique evidence that explosive concentric contractions are 60% more effective at utilising the available force capacity of the muscle, that was explained by superior agonist activation. This work provides a comprehensive analysis of the association between athletic performance and RFD, the differential effects of maximum vs. explosive strength training, and the influence of contraction type on the capacity for RFD.

Page generated in 0.1277 seconds