Abstract：
:Human runners adjust the stiffness of their stance leg to accommodate surface stiffness during steady state running. This adjustment allows runners to maintain similar center of mass movement (e.g., ground contact time and stride frequency) regardless of surface stiffness. When runners encounter abrupt transitions in the running surface, they must either make a rapid adjustment or allow the change in the surface stiffness to disrupt their running mechanics. Our goal was to determine how quickly runners adjust leg stiffness when they encounter an abrupt but expected change in surface stiffness that they have encountered previously. Six human subjects ran at 3 m s(-1) on a rubber track with two types of rubber surfaces: a compliant "soft" surface (ksurf = 21.3 kN m(-1) and a non-compliant "hard" surface (ksurf = 533 kN m(-1). We found that runners completely adjusted leg stiffness for their first step on the new surface after the transition. For example, runners decreased leg stiffness by 29% between the last step on the soft surface and the first step on the hard surface (from 10.7 kN m(-1) to 7.6 kN m(-1), respectively). As a result, the vertical displacement of the center of mass during stance ( approximately 7 cm) did not change at the transition despite a reduction in surface compression from 6 cm to less than 0.25 cm. By rapidly adjusting leg stiffness, each runner made a smooth transition between surfaces so that the path of the center of mass was unaffected by the change in surface stiffness.
journal_name
J Biomechjournal_title
Journal of biomechanicsauthors
Ferris DP,Liang K,Farley CTdoi
10.1016/s0021-9290(99)00078-0keywords:
subject
Has Abstractpub_date
1999-08-01 00:00:00pages
787-94issue
8eissn
0021-9290issn
1873-2380pii
S0021-9290(99)00078-0journal_volume
32pub_type
临床试验,杂志文章,随机对照试验abstract：:Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teenage years. Although the reasons for the a...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.02.009
更新日期：2015-04-13 00:00:00
abstract：:Factors were examined which altered the propagation of aortic dissections in canine aortas. Thoracic aortas were removed from sacrificed dogs from the distal end of the arch to the diaphragm. An intimal tear was created at the proximal end of the aorta. The dissection was propagated using a pulsatile pressure system w...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(87)90268-5
更新日期：1987-01-01 00:00:00
abstract：:The longitudinal growth of long bones occurs in growth plates where chondrocytes synthesize cartilage that is subsequently ossified. Altered growth and subsequent deformity resulting from abnormal mechanical loading is often referred to as mechanical modulation of bone growth. This phenomenon has key implications in t...
journal_title：Journal of biomechanics
pub_type： 杂志文章,评审
doi：10.1016/j.jbiomech.2009.05.021
更新日期：2009-08-25 00:00:00
abstract：:A stereoradiographic method was developed to measure the three-dimensional shape of the rib cage in vivo in order to provide descriptive data and to study symmetry in the normal population. The method is also intended for use in description of rib asymmetry in scoliosis. Rib midlines were reconstructed from digitized ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(88)90127-3
更新日期：1988-01-01 00:00:00
abstract：:The use of cadavers for orthopaedic biomechanics research is well established, but presents difficulties to researchers in terms of cost, biosafety, availability, and ease of use. High fidelity composite models of human bone have been developed for use in biomechanical studies. While several studies have utilized comp...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.12.050
更新日期：2016-02-29 00:00:00
abstract：:The gait cycle is usually analyzed using one of two conventions: heel contact initiates the cycle and stance is followed by swing phases or toe-off initiates the cycle and swing then stance phases are analyzed. The purpose of the study is to demonstrate that based on a consideration of relevant biomechanical measures,...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(94)90025-6
更新日期：1994-04-01 00:00:00
abstract：:Although micromechanical finite-element models are being increasingly used to help interpret the results of bio-mechanical tests, there has not yet been a systematic study of the numerical errors and uncertainties that occur with these methods. In this work, finite-element models of human L1 vertebra have been used to...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/s0021-9290(98)00108-0
更新日期：1998-10-01 00:00:00
abstract：:In cementless total hip arthroplasty, osteoporosis may jeopardize the achievement of immediate stability and lead to migration of anatomically shaped femoral stems. Poor quality of proximal cancellous bone per se may also affect the rate of osseointegration. In a selected group of female total hip arthroplasty patient...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2010.10.012
更新日期：2011-01-11 00:00:00
abstract：:The mechanical energy expenditures (MEEs) of two human lower extremity models with different sources of mechanical energy - (1) muscles and (2) joint moments - were compared theoretically. Sources of mechanical energy producing movement of Model 1 were eight muscle, three of which were two-joint muscles. Sources of me...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(95)00083-6
更新日期：1996-04-01 00:00:00
abstract：:Transitory tasks, such as gait termination, involve interactions between neural and biomechanical factors that challenge postural stability and head stabilization patterns in older adults. The aim of the study was to compare upper body patterns of acceleration during planned gait termination at different speeds betwee...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2017.10.019
更新日期：2017-12-08 00:00:00
abstract：:Mechanical environment in callus is determinant for the evolution of bone healing. However, recent mechanobiological computational works have underestimated the effect that growth exerts on the mechanical environment of callus. In the present work, we computationally evaluate the significance of growth-induced stresse...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2011.04.021
更新日期：2011-06-03 00:00:00
abstract：:Stem-cement and cement-bone interfacial failures as well as cement fractures have been noted in cemented total hip arthroplasty (THA) as the cause of aseptic loosening. Attempts to reduce the risk of femoral component loosening include improving the stem-cement interface by various coatings, using a textured or porous...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2012.12.010
更新日期：2013-03-15 00:00:00
abstract：OBJECTIVES:To assess the ability of a biomechanical impact model to predict the likelihood of distal radius fracture in children using data gathered for a previous epidemiological case-control study of falls from playground equipment. METHODOLOGY:Factor of Risk (FR) values were generated for each of selected subjects ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2004.11.028
更新日期：2006-01-01 00:00:00
abstract：:Stress, strain and modulus are regularly used to characterize material properties of tissue samples. However, when comparing results from different studies it is evident the reported material properties, particularly failure strains, vary hugely. The aim of our study was to characterize how and why specimen length and...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2010.04.040
更新日期：2010-08-26 00:00:00
abstract：:The purpose of this study was to analyze the reproducibility of kinematic, dynamometric and derived mechanical energy parameters in the pole vault as a main precondition for the practical applicability of the concept of energy exchange in the pole vault. A total of 46 vaults of six experienced vaulters were analyzed. ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2005.03.027
更新日期：2006-01-01 00:00:00
abstract：:Although arterial blood flow is physiologically non-periodic under resting conditions, periodic flow assumption has been widely adopted in most hemodynamic studies. So far, it remains unclear how the non-periodicity of blood flow would influence local hemodynamic parameters, especially wall shear stress (WSS) that ass...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2020.109617
更新日期：2020-03-05 00:00:00
abstract：:Although a significant proportion of patient falls occur during egress from the hospital bed, the biomechanical adaptations during egress from different bed heights are still largely unknown. The purpose of this study was to evaluate the effect of hospital bed height on natural transition during egress in patients wit...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2020.110116
更新日期：2021-01-22 00:00:00
abstract：:Nonconformity between the polyethylene liner and the metal shell may exist in modular acetabular components by design, due to manufacturing tolerances, or from locking mechanisms that attach the polyethylene liner to the metal shell. Relative motion at the liner/shell interface has been associated with backside wear, ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/s0021-9290(98)00030-x
更新日期：1998-05-01 00:00:00
abstract：:Stepping down an elevation in ongoing gait is a common task that can cause falls when the level change is unexpected. The aim of this study was to compare expected and unexpected stepping down. We hypothesized that unexpected stepping would lead to loss of control over the movement and potentially falls due to bucklin...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2007.06.009
更新日期：2007-01-01 00:00:00
abstract：:In the context of reconciling the mechanical properties of trabecular bone measured from in vitro mechanical testing with the true in situ behavior, recent attention has focused on the "side-artifact" which results from interruption of the trabecular network along the sides of machined specimens. The objective of this...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2007.05.008
更新日期：2007-01-01 00:00:00
abstract：:Knowledge about in vivo spinal loads is required for the identification of risk factors for low back pain and for realistic preclinical testing of spinal implants. Therefore, the aim of the present study was to measure the in vivo forces on a vertebral body replacement (VBR) during trunk flexion and to analyze in deta...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.01.007
更新日期：2015-02-26 00:00:00
abstract：:The reference point indentation (RPI) method is a microindentation technique involving successive indentation cycles. We employed RPI to measure average stiffness (Ave US), indentation distance increase (IDI), total indentation distance (TID), average energy dissipated (Ave ED), and creep indentation distance (CID) of...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2013.04.003
更新日期：2013-06-21 00:00:00
abstract：:Confinement of the heel due to the counter of the shoe is believed to influence heel pad biomechanics. Using a two-dimensional finite element model of the heel pad and shoe during a simulation of static standing, the aim of this study was to quantify the potential effect of confinement on internal heel pad stress. Non...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2007.01.004
更新日期：2007-01-01 00:00:00
abstract：:Muscle force is modulated by varying the number of active motor units and their firing rates. For the past five decades, the notion that the magnitude of the firing rates is directly related to motor unit size and recruitment threshold has been widely accepted. This construct, here named the After-hyperpolarization sc...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2014.12.003
更新日期：2015-01-21 00:00:00
abstract：:A finite element model was used to investigate the counter-intuitive experimental observation that some regions of the aponeuroses of a loaded and contracting muscle may shorten rather than undergo an expected lengthening. The model confirms the experimental findings and suggests that pennation angle plays a significa...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2010.01.005
更新日期：2010-05-07 00:00:00
abstract：:A three-dimensional finite element model of the human head is presented. The model has been validated against two sets of experimental results. To assess injury likelihood of the head subjected to impact loading, the structural intensity (SI) methodology is introduced in accordance with the prevailing practice in expe...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2004.11.015
更新日期：2006-01-01 00:00:00
abstract：:In order to gain better understanding for rheology of an isolated red blood cell (RBC) and a group of multiple RBCs, new continuum models for describing mechanical properties of cellular structures of an RBC and inter-cellular interactions among multiple RBCs are developed. The viscous property of an RBC membrane, whi...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.11.027
更新日期：2016-07-26 00:00:00
abstract：BACKGROUND:Children with spastic cerebral palsy (CP) experience secondary musculoskeletal adaptations, affecting the mechanical and material properties of muscles and tendons. CP-related changes in the spastic muscle are well documented whilst less is known about the tendon. From a clinical perspective, it is important...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2016.07.020
更新日期：2016-09-06 00:00:00
abstract：:The finite element method described in this study provides an easy method to simulate the kinetics of multibody mechanisms. It is used in order to develop a musculoskeletal model of the shoulder mechanism. Each relevant morphological structure has been represented by an appropriate element. For the shoulder mechanism ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(94)90065-5
更新日期：1994-05-01 00:00:00
abstract：:The purpose of this study was to investigate the effects of temperature, velocity and load on the gliding resistance (GR) of flexor digitorum profundus (FDP) tendons in a human cadaver model. A total of 40 FDP tendons from the index through small digits of ten human cadavers were tested to assess the effect of tempera...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2011.01.011
更新日期：2011-04-29 00:00:00
