Jos Vanrenterghem | Liverpool John Moores University (original) (raw)
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Papers by Jos Vanrenterghem
Journal of Biomechanics, Jan 1, 2004
Gait & posture, Jan 1, 2006
Human movement …, Jan 1, 2004
The Journal of Strength & …, Jan 1, 2004
The vertical jump is a widely used activity to develop explosive strength, particularly in plyome... more The vertical jump is a widely used activity to develop explosive strength, particularly in plyometric and maximal power training programs. It is a multijoint action that requires substantial muscular effort from primarily the ankle, knee, and hip joints. It is not known if submaximal performances of a vertical jump have a proportional or differential training effect on the major lower-limb muscles compared to maximal jump performance. Therefore, the purpose of this study was to investigate the contribution that each of the major lower-limb joints makes to vertical jump performance as jump height increases and to comment on the previously mentioned uncertainty. Adult males (N = 20) were asked to perform a series of submaximal (LOW and HIGH) and maximal (MAX) vertical jumps while using an arm swing. Force, motion, and electromyographical data were recorded during each performance and used to compute a range of kinematic and kinetic data, including ankle, knee, and hip joint torques, powers, and work done. It was found that the contribution to jump height made by the ankle and knee joints remains largely unchanged as jump height increases (work done at the ankle: LOW =1.80, HIGH = 1.97, MAX = 2.06 J.kg(-1), F = 3.596, p = 0.034; knee: LOW = 1.62, HIGH = 1.77, MAX = 1.94 J.kg(-1), F = 1.492, p = 0.234) and that superior performance in the vertical jump is achieved by a greater effort of the hip extensor muscles (work done at the hip: LOW = 1.03, HIGH = 1.84, MAX = 3.24 J.kg(-1), F = 110.143, p < 0.001). It was concluded that the role of submaximal and maximal jumps can be differentiated in terms of their effect on ankle, knee, and hip joint muscles and may be of some importance to training regimens in which these muscles need to be differentially trained.
Ergonomics, Jan 1, 2001
The present study was designed to investigate the determination of vertical jumping height by mea... more The present study was designed to investigate the determination of vertical jumping height by means of force plate measurements. Four different sources of error influence this determination: the measurement of body mass, the determination of take off, the integration frequency, and the assessment of the initial conditions influencing the determination of the start of the movement. A theoretical model was utilized to simulate the vertical ground reaction forces in vertical jumping and to compare the outcome of analytical and numerical double integration of the vertical acceleration of the body centre of mass. A high integration frequency and an optimizing loop for body mass determination were found to be important and should be taken into account when determining jumping height parameters.
Medical engineering & …, Jan 1, 2007
Gait & posture, Jan 1, 2006
The Journal of Strength & …, Jan 1, 2008
It is commonly accepted that vertical jump performance is a good indicator of maximal joint power... more It is commonly accepted that vertical jump performance is a good indicator of maximal joint power. Some studies, however, have indicated that knee joint power output in the vertical jump is limited due to forward trunk inclination early in the push-off. The aim of this experimental study was to investigate the effect of forward trunk inclination on joint power output in vertical jumping. A group of 20 male subjects performed maximal vertical countermovement jumps from stance while minimizing the contribution of arm swing by holding their hands on their hips (arms akimbo). They also performed maximal jumps while holding the trunk as upright as possible throughout the jump, still holding the arms akimbo. Jump height, joint kinematics (angles), and joint kinetics (torque, power) were calculated. Jump height of vertical jumps while holding the trunk upright was 10% less than in normal jumps. Hip joint power was decreased by 37% while knee joint power was increased by 13%. Ankle joint power did not change. These results demonstrated that maximal jump performance does not necessarily represent maximal power of each individual joint. The implication is that jump performance may well be a good representation of overall joint power; it is, however, not an accurate measure to evaluate maximal individual joint power as part of contemporary training and rehabilitation methods.
Journal of sports …, Jan 1, 2006
The aims of this study were to investigate the energy build-up and dissipation mechanisms associa... more The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.
Journal of …, Jan 1, 2008
Journal of sports sciences, Jan 1, 2003
... Please use this identifier to cite or link to this item: Record Details. Record ID, 217905. R... more ... Please use this identifier to cite or link to this item: Record Details. Record ID, 217905. Record Type, journalArticle. Author, A LEES; Jos Vanrenterghem [801001244990] - Ghent University; Dirk De Clercq [801000542045] - Ghent University Dirk.DeClercq@UGent.be. ...
Gait & posture, Jan 1, 2010
Journal of Biomechanics, Jan 1, 2004
Gait & posture, Jan 1, 2006
Human movement …, Jan 1, 2004
The Journal of Strength & …, Jan 1, 2004
The vertical jump is a widely used activity to develop explosive strength, particularly in plyome... more The vertical jump is a widely used activity to develop explosive strength, particularly in plyometric and maximal power training programs. It is a multijoint action that requires substantial muscular effort from primarily the ankle, knee, and hip joints. It is not known if submaximal performances of a vertical jump have a proportional or differential training effect on the major lower-limb muscles compared to maximal jump performance. Therefore, the purpose of this study was to investigate the contribution that each of the major lower-limb joints makes to vertical jump performance as jump height increases and to comment on the previously mentioned uncertainty. Adult males (N = 20) were asked to perform a series of submaximal (LOW and HIGH) and maximal (MAX) vertical jumps while using an arm swing. Force, motion, and electromyographical data were recorded during each performance and used to compute a range of kinematic and kinetic data, including ankle, knee, and hip joint torques, powers, and work done. It was found that the contribution to jump height made by the ankle and knee joints remains largely unchanged as jump height increases (work done at the ankle: LOW =1.80, HIGH = 1.97, MAX = 2.06 J.kg(-1), F = 3.596, p = 0.034; knee: LOW = 1.62, HIGH = 1.77, MAX = 1.94 J.kg(-1), F = 1.492, p = 0.234) and that superior performance in the vertical jump is achieved by a greater effort of the hip extensor muscles (work done at the hip: LOW = 1.03, HIGH = 1.84, MAX = 3.24 J.kg(-1), F = 110.143, p < 0.001). It was concluded that the role of submaximal and maximal jumps can be differentiated in terms of their effect on ankle, knee, and hip joint muscles and may be of some importance to training regimens in which these muscles need to be differentially trained.
Ergonomics, Jan 1, 2001
The present study was designed to investigate the determination of vertical jumping height by mea... more The present study was designed to investigate the determination of vertical jumping height by means of force plate measurements. Four different sources of error influence this determination: the measurement of body mass, the determination of take off, the integration frequency, and the assessment of the initial conditions influencing the determination of the start of the movement. A theoretical model was utilized to simulate the vertical ground reaction forces in vertical jumping and to compare the outcome of analytical and numerical double integration of the vertical acceleration of the body centre of mass. A high integration frequency and an optimizing loop for body mass determination were found to be important and should be taken into account when determining jumping height parameters.
Medical engineering & …, Jan 1, 2007
Gait & posture, Jan 1, 2006
The Journal of Strength & …, Jan 1, 2008
It is commonly accepted that vertical jump performance is a good indicator of maximal joint power... more It is commonly accepted that vertical jump performance is a good indicator of maximal joint power. Some studies, however, have indicated that knee joint power output in the vertical jump is limited due to forward trunk inclination early in the push-off. The aim of this experimental study was to investigate the effect of forward trunk inclination on joint power output in vertical jumping. A group of 20 male subjects performed maximal vertical countermovement jumps from stance while minimizing the contribution of arm swing by holding their hands on their hips (arms akimbo). They also performed maximal jumps while holding the trunk as upright as possible throughout the jump, still holding the arms akimbo. Jump height, joint kinematics (angles), and joint kinetics (torque, power) were calculated. Jump height of vertical jumps while holding the trunk upright was 10% less than in normal jumps. Hip joint power was decreased by 37% while knee joint power was increased by 13%. Ankle joint power did not change. These results demonstrated that maximal jump performance does not necessarily represent maximal power of each individual joint. The implication is that jump performance may well be a good representation of overall joint power; it is, however, not an accurate measure to evaluate maximal individual joint power as part of contemporary training and rehabilitation methods.
Journal of sports …, Jan 1, 2006
The aims of this study were to investigate the energy build-up and dissipation mechanisms associa... more The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.
Journal of …, Jan 1, 2008
Journal of sports sciences, Jan 1, 2003
... Please use this identifier to cite or link to this item: Record Details. Record ID, 217905. R... more ... Please use this identifier to cite or link to this item: Record Details. Record ID, 217905. Record Type, journalArticle. Author, A LEES; Jos Vanrenterghem [801001244990] - Ghent University; Dirk De Clercq [801000542045] - Ghent University Dirk.DeClercq@UGent.be. ...
Gait & posture, Jan 1, 2010