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Contractile And Non-Contractile Tissue Volume And Distribution In Ankle Muscles Of Young And Older Adults, Christopher J. Hasson, Jane A. Kent-Braun, Graham E. Caldwell
Contractile And Non-Contractile Tissue Volume And Distribution In Ankle Muscles Of Young And Older Adults, Christopher J. Hasson, Jane A. Kent-Braun, Graham E. Caldwell
Graham E. Caldwell
Magnetic resonance imaging (MRI) enables accurate in vivo quantification of human muscle volumes, which can be used to estimate subject-specific muscle force capabilities. An important consideration is the amount of contractile and non-contractile tissue in the muscle compartment, which will influence force capability. We quantified age-related differences in the proportion and distribution of contractile and non-contractile tissue in the dorsiflexor and plantar flexor (soleus, and medial and lateral heads of gastrocnemius) muscles, and examined how well these volumes can be estimated from single MRI cross-sections. Axial MRIs of the left leg for 12 young (mean age 27 years) and 12 …
Contractile And Elastic Ankle Joint Muscular Properties In Young And Older Adults, Christopher J. Hasson, Ross H. Miller, Graham E. Caldwell
Contractile And Elastic Ankle Joint Muscular Properties In Young And Older Adults, Christopher J. Hasson, Ross H. Miller, Graham E. Caldwell
Graham E. Caldwell
The purpose of this study was to investigate age-related differences in contractile and elastic properties of both dorsi- (DF) and plantarflexor (PF) muscles controlling the ankle joint in young and older adults. Experimental data were collected while twelve young and twelve older male and female participants performed maximal effort isometric and isovelocity contractions on a dynamometer. Equations were fit to the data to give torque-angle (Th) and torque-angular velocity (Tv) relations. Muscle series-elasticity was measured during ramped dynamometer contractions using ultrasonography to measure aponeurosis extension as a function of torque; second order polynomials were used to characterize the torqueextension (TDL) …