Abstract:
:The purpose of the present work was to study swimmers' efficiency during the underwater phase of the grab start. Eight high-level swimmers participated in this study. They performed two types of start: a regular grab start (with underwater leg propulsion after the glide) and a grab start with no underwater movement (swimmers had to remain in a streamlined position). Four cameras filmed the entire underwater phase of all starts. Nine anatomic landmarks were identified on the swimmers' bodies and their positions were calculated using a modified double plan DLT technique. From these positions and Dempster's anthropometric data, the center of mass position and velocity were also determined. Kinetic energies were also calculated. This velocity and kinetic energies for the two types of start were compared. Swimmers began underwater leg propulsion 1.69 m too soon. The global and internal energies were significantly higher for the start with underwater leg propulsion. Nevertheless, swimmers' velocities were equivalent for both starts. These results suggest that the swimmers did not use the underwater phase of the start efficiently: By kicking too soon, they did not succeed in producing higher velocities and thus wasted energy.
journal_name
J Appl Biomechjournal_title
Journal of applied biomechanicsauthors
Elipot M,Dietrich G,Hellard P,Houel Ndoi
10.1123/jab.26.4.501subject
Has Abstractpub_date
2010-11-01 00:00:00pages
501-7issue
4eissn
1065-8483issn
1543-2688journal_volume
26pub_type
杂志文章abstract::In animal models, hundreds of repetitions of upper extremity (UE) task practice promote neural adaptation and functional gain. Recently, we demonstrated improved UE function following a similar intervention for people after stroke. In this secondary analysis, computerized measures of UE task performance were used to i...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.28.3.304
更新日期:2012-07-01 00:00:00
abstract::We tested the ability of healthy elderly persons to use anticipatory synergy adjustments (ASAs) prior to a self-triggered perturbation of one of the fingers during a multifinger force production task. An index of a force-stabilizing synergy was computed reflecting covariation of commands to fingers. The subjects produ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.24.2.175
更新日期:2008-05-01 00:00:00
abstract::The aim of this study was to determine the effects of pole length on energy cost and kinematics in cross country double poling. Seven sub-elite male athletes were tested using pole sets of different lengths (ranging between 77% and 98% of participants' body height). Tests were conducted on a treadmill, set to a 2% inc...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2016-0071
更新日期:2017-07-01 00:00:00
abstract::Cutting maneuvers can be executed at a range of angles and speeds, and these whole-body task descriptors are closely associated with lower-limb mechanical loading. Asymmetries in angle and speed when changing direction off the operated and nonoperated limbs after anterior cruciate ligament reconstruction may therefore...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2020-0110
更新日期:2021-01-22 00:00:00
abstract::The objective of this study was to determine if a foam testing condition and/or nonlinear analysis methods can be used to identify differences between age stratified subgroups of older adults when conducting the Limits of Stability assessment. Ninety older adults participated in this study. A force plate was used to r...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2016-0019
更新日期:2017-12-01 00:00:00
abstract::In this paper, a literature review is presented regarding the hydrodynamic effects of different hand and arm movements during swimming with the aim to identify lacunae in current methods and knowledge, and to distil practical guidelines for coaches and swimmers seeking to increase swimming speed. Experimental and nume...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章,评审
doi:10.1123/jab.2016-0064
更新日期:2017-02-01 00:00:00
abstract::Cartilage material properties provide important insights into joint health, and cartilage material models are used in whole-joint finite element models. Although the biphasic model representing experimental creep indentation tests is commonly used to characterize cartilage, cartilage short-term response to loading is ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.29.3.292
更新日期:2013-06-01 00:00:00
abstract::One potential ACL injury situation is due to contact with another person or object during the flight phase, thereby causing the person to land improperly. Conversely, athletes often have flight-phase collisions but do land safely. Therefore, to better understand ACL injury causation and methods by which people typical...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2013-0331
更新日期:2014-10-01 00:00:00
abstract::The aim of this systematic review was to evaluate the impact of bilaterally symmetrical backpack systems borne on the posterior trunk on walking biomechanics, as backpacks represent the most prevalent method of load carriage in the military and civilian population. A search of electronic databases was performed for st...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章,meta分析,评审
doi:10.1123/jab.2015-0339
更新日期:2016-12-01 00:00:00
abstract::Virtual reality (VR) paradigms have proved to be a valid method to challenge and perturb balance. There is little consensus in the literature on the best protocol design to perturb balance and induce postural sway. Current VR interventions still lack a well-defined standardized metric to generate a virtual environment...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2019-0130
更新日期:2020-05-11 00:00:00
abstract::The coupling between the residual limb and the lower-limb prosthesis is not rigid. As a result, external loading produces movement between the prosthesis and residual limb that can lead to undesirable soft-tissue shear stresses. As these stresses are difficult to measure, limb loading is commonly used as a surrogate. ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2019-0362
更新日期:2020-11-03 00:00:00
abstract::It has been suggested that noncontact anterior cruciate ligament injury commonly occurs during sports requiring acute deceleration or landing motion and that female athletes are more likely to sustain the injury than male athletes. The purpose of this study was to make task-to-task and male-female comparisons of knee ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.29.6.749
更新日期:2013-12-01 00:00:00
abstract::This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear versus polynomial regression models, (2) concentric-only versus eccentric-concentric bench press variants, as well as (3) the within-participants versus the between-participants variability of the velocity ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2017-0266
更新日期:2018-06-01 00:00:00
abstract::Use of a shank shell has been shown to estimate tibial transverse rotations better than skin-mounted markers. However, the day-to-day reliability of the transverse tibial rotations using an individually molded shank shell has not been previously investigated. This study examined the between-tests and trials reliabilit...
journal_title:Journal of applied biomechanics
pub_type: 临床试验,杂志文章
doi:10.1123/jab.21.2.198
更新日期:2005-05-01 00:00:00
abstract::The length of a muscle's moment arm can be estimated non-invasively using ultrasound, and the tendon excursion method. The main assumption with the tendon excursion method, however, is that the force acting on the tendon during passive rotation is constant. However, passive force changes through the range of motion, a...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2017-0263
更新日期:2018-01-24 00:00:00
abstract::In running, foot contact patterns (rear-, mid-, or forefoot contact) influence impact intensity and initial ankle and foot kinematics. The aim of the study was to compare impact intensity and its spatial distribution under the foot between different foot contact patterns. Forty-nine subjects ran at 3.2 m·s-1 over a le...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2016-0206
更新日期:2017-12-01 00:00:00
abstract::The segment principal moments of inertia of a sample of 7 elderly males and 12 elderly females were estimated using a model based on stacked elliptical cylinders at 2-cm intervals. Apart from the thigh, all male parameters were larger than female parameters. The largest differences were for the lower trunk and hand an...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.9.4.287
更新日期:1993-11-01 00:00:00
abstract::Given its apparent representation of cumulative (vs peak) loads, this feasibility study investigates vertical ground reaction impulse (vGRI) as a real-time biofeedback variable for gait training aimed at reducing lower limb loading. Fifteen uninjured participants (mean age = 27 y) completed 12 2-min trials, 1 at each ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2017-0004
更新日期:2018-04-01 00:00:00
abstract::The purpose of this study was to determine if children exhibit greater variability in center of mass movement and kinetics compared with adults in vertical jumping. Countermovement jumps with arms (CMJA) and without arms (CMJ) performed by 20 female children and 20 female adults were examined using force platform. The...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2014-0043
更新日期:2014-12-01 00:00:00
abstract::Hamstring stiffness (K(HAM)) and leg stiffness (K(LEG)) are commonly examined relative to athletic performance and injury risk. Given these may be modifiable, it is important to understand day-to-day variations inherent in these measures before use in training studies. In addition, the extent to which K(HAM) and K(LEG...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2014-0289
更新日期:2015-10-01 00:00:00
abstract::The use of foot orthoses has been evaluated during a variety of functional activities. Twelve college-aged active females wore two types of foot orthoses and performed a vertical jump to determine the biomechanical effect of the orthoses on lower extremity transverse plane movement during landing. Data collection incl...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.25.4.387
更新日期:2009-11-01 00:00:00
abstract::Less than 50% of athletes pass criteria to return to sports (RTS) 6 months after ACL reconstruction (ACLR). Using data on 38 noncopers, we hypothesized that preoperative age, quadriceps strength index (QI), and knee flexion moments (KFM) during gait would predict the ability to pass/fail RTS criteria and that preopera...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章,随机对照试验
doi:10.1123/jab.28.4.366
更新日期:2012-08-01 00:00:00
abstract::This study aimed to examine the effects of knee position on the reliability and production of peak force (PF) and rate of force development (RFD) characteristics during an isometric squat. Fourteen resistance-trained females performed isometric squats at 90, 120, and 150° knee angles (corresponding to parallel, half, ...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2017-0213
更新日期:2018-04-01 00:00:00
abstract::To date, biomechanical analyses of soccer kicking have focused predominantly on lower-extremity motions, with little emphasis on the trunk and upper body. The purpose of this study was to evaluate differences in trunk axial kinematics between novice (n = 10) and skilled (n = 10) participants, as well as to establish t...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2014-0188
更新日期:2015-10-01 00:00:00
abstract::The purpose of this study was to determine whether a lateral wedge insole reduces the external knee adduction moment during slope walking. Twenty young, healthy subjects participated in this study. Subjects walked up and down a slope using 2 different insoles: a control flat insole and a 7° lateral wedge insole. A thr...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2014-0247
更新日期:2015-12-01 00:00:00
abstract::Wrist splints are commonly prescribed to limit wrist motion and provide support at night and during inactive periods but are often used in the workplace. In theory, splinting the wrist should reduce wrist extensor muscle activity by stabilizing the joint and reducing the need for co-contraction to maintain posture. Te...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.24.3.298
更新日期:2008-08-01 00:00:00
abstract::We have developed a 2-D analytical biomechanical model for monoarticular open kinetic-chain exercises with lever selectorized equipment, and different relative placement between the joint center of rotation (J) and the center of rotation (C) of the resistance input lever ("off-center" exercises). All the relevant geom...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.26.1.73
更新日期:2010-02-01 00:00:00
abstract::The purpose of this study was to evaluate whether agonist muscle fatigue changed the coactivation time and the co-contraction magnitude of the agonist and antagonist muscle, and if the agonist muscle fatigue produced bias (constant error: CE) and inconsistency (variable error: VE) of the force. Subjects are 10 healthy...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.25.4.293
更新日期:2009-11-01 00:00:00
abstract::Girls' lacrosse participation and head injury rates have increased within the past decade. In response, optional headgear was implemented following the recently developed ASTM International (ASTM) lacrosse headgear performance standards. It remains unknown how lacrosse headgear responds to blunt impacts after use. Our...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2018-0457
更新日期:2019-08-01 00:00:00
abstract::The aim was to compare torque and rate of torque development of lower limb muscles between older women with functional and slow gait speeds to determine which muscle group is the best predictor of functional gait speed, and to establish strength thresholds needed for functional walking speed. Torque and rate of torque...
journal_title:Journal of applied biomechanics
pub_type: 杂志文章
doi:10.1123/jab.2016-0354
更新日期:2018-08-01 00:00:00