title: Gait analysis in chronic heart failure: The calf as a locus of impaired walking capacity.
abstract: Reduced walking capacity, a hallmark of chronic heart failure (CHF), is strongly correlated with hospitalization and morbidity. The aim of this work was to perform a detailed biomechanical gait analysis to better identify mechanisms underlying reduced walking capacity in CHF. Inverse dynamic analyses were conducted in CHF patients and age- and exercise level-matched control subjects on an instrumented treadmill at self-selected treadmill walking speeds and at speeds representing +20% and -20% of the subjects' preferred speed. Surprisingly, no difference in preferred speed was observed between groups, possibly explained by an optimization of the mechanical cost of transport in both groups (the mechanical cost to travel a given distance; J/kg/m). The majority of limb kinematics and kinetics were also similar between groups, with the exception of greater ankle dorsiflexion angles during stance in CHF. Nevertheless, over two times greater ankle plantarflexion work during stance and per distance traveled is required for a given triceps surae muscle volume in CHF patients. This, together with a greater reliance on the ankle compared to the hip to power walking in CHF patients, especially at faster speeds, may contribute to the earlier onset of fatigue in CHF patients. This observation also helps explain the high correlation between triceps surae muscle volume and exercise capacity that has previously been reported in CHF. Considering the key role played by the plantarflexors in powering walking and their association with exercise capacity, our findings strongly suggest that exercise-based rehabilitation in CHF should not omit the ankle muscle group.
authors.affiliation: The School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, WA, 6009, Australia.
authors.forename: Fausto A
authors.initials: FA
authors.lastname: Panizzolo
authors.affiliation: Advanced Heart Failure and Cardiac Transplant Service, Royal Perth Hospital, Perth, WA 6000, Australia; School of Physiotherapy and Exercise Science, Curtin University, Perth, WA 6102, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Maiorana
authors.affiliation: The School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, WA, 6009, Australia.
authors.forename: Louise H
authors.initials: LH
authors.lastname: Naylor
authors.affiliation: Advanced Heart Failure and Cardiac Transplant Service, Royal Perth Hospital, Perth, WA 6000, Australia; Envision Medical Imaging, Perth, Western Australia, Australia.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Dembo
authors.affiliation: Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Gold Coast, QLD, 4222, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Lloyd
authors.affiliation: The School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, WA, 6009, Australia; Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Green
authors.affiliation: The School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, WA, 6009, Australia. Electronic address: jonas.rubenson@uwa.edu.au.
authors.forename: Jonas
authors.initials: J
authors.lastname: Rubenson
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D016138:Walking / Q000502:physiology*
keywords: Gait mechanics; Heart failure; Muscle work; Triceps surae