A Simple Method for Measuring Lower Limb Force, Velocity and Power Capabilities During Jumping

2018 ◽  
pp. 65-96 ◽  
Author(s):  
Pierre Samozino
Keyword(s):  
Lower Limb ◽  
Simple Method ◽  
Force Velocity

Relationships between Lower Limb Muscle Characteristics and Force–Velocity Profiles Derived during Sprinting and Jumping

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
PHILLIP BELLINGER ◽  
MATTHEW BOURNE ◽  
STEVEN DUHIG ◽  
ELINE LIEVENS ◽  
BEN KENNEDY ◽  
...  
Keyword(s):  
Lower Limb ◽  
Velocity Profiles ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Force Velocity

scholarly journals Stiffness-distortion sarcomere model for muscle simulation

1999 ◽  
Vol 87 (5) ◽  
pp. 1861-1876 ◽  
Author(s):  
Maria V. Razumova ◽  
Anna E. Bukatina ◽  
Kenneth B. Campbell
Keyword(s):  
Differential Equations ◽  
Kinetic Scheme ◽  
Simple Method ◽  
Thin Filaments ◽  
Cross Bridge ◽  
Model Predictions ◽  
Force Velocity ◽  
Cross Bridges ◽  
Shearing Motion ◽  
State Kinetic

A relatively simple method is presented for incorporating cross-bridge mechanisms into a muscle model. The method is based on representing force in a half sarcomere as the product of the stiffness of all parallel cross bridges and their average distortion. Differential equations for sarcomeric stiffness are derived from a three-state kinetic scheme for the cross-bridge cycle. Differential equations for average distortion are derived from a distortional balance that accounts for distortion entering and leaving due to cross-bridge cycling and for distortion imposed by shearing motion between thick and thin filaments. The distortion equations are unique and enable sarcomere mechanodynamics to be described by only a few ordinary differential equations. Model predictions of small-amplitude step and sinusoidal responses agreed well with previously described experimental results and allowed unique interpretations to be made of various response components. Similarly good results were obtained for model reproductions of force-velocity and large-amplitude step and ramp responses. The model allowed reasonable predictions of contractile behavior by taking into account what is understood to be basic muscle contractile mechanisms.

Lower Limb Force, Velocity, Power Capabilities during Leg Press and Squat Movements

2017 ◽  
Vol 38 (14) ◽  
pp. 1083-1089 ◽  
Author(s):  
Johnny Padulo ◽  
Gian Migliaccio ◽  
Luca Ardigò ◽  
Bruno Leban ◽  
Marco Cosso ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Effect Size ◽  
Power Output ◽  
Lower Limb ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Optimal Velocity ◽  
Leg Press ◽  
Maximal Force ◽  
Force Velocity

AbstractThe aim was to compare lower-limb power, force, and velocity capabilities between squat and leg press movements. Ten healthy sportsmen performed ballistic lower-limb push-offs against 5-to-12 different loads during both the squat and leg press. Individual linear force-velocity and polynomial power-velocity relationships were determined for both movements from push-off mean force and velocity measured continuously with a pressure sensor and linear encoder. Maximal power output, theoretical maximal force and velocity, force-velocity profile and optimal velocity were computed. During the squat, maximal power output (17.7±3.59 vs. 10.9±1.39 W·kg−1), theoretical maximal velocity (1.66±0.29 vs. 0.88±0.18 m·s−1), optimal velocity (0.839±0.144 vs. 0.465±0.107 m·s−1), and force-velocity profile (−27.2±8.5 vs. −64.3±29.5 N·s·m−1·kg−1) values were significantly higher than during the leg press (p=0.000, effect size=1.72–3.23), whereas theoretical maximal force values (43.1±8.6 vs. 51.9±14.0 N·kg−1, p=0.034, effect size=0.75) were significantly lower. The mechanical capabilities of the lower-limb extensors were different in the squat compared with the leg press with higher maximal power due to much higher velocity capabilities (e.g. ability to produce force at high velocities) even if moderately lower maximal force qualities.

A simple method for assessment of muscle force, velocity, and power producing capacities from functional movement tasks

2016 ◽  
Vol 35 (13) ◽  
pp. 1287-1293 ◽  
Author(s):  
Milena Z. Zivkovic ◽  
Sasa Djuric ◽  
Ivan Cuk ◽  
Dejan Suzovic ◽  
Slobodan Jaric
Keyword(s):  
Muscle Force ◽  
Simple Method ◽  
Functional Movement ◽  
Force Velocity

scholarly journals Jump height is a poor indicator of lower limb maximal power output: theoretical demonstration, experimental evidence and practical solutions

2018 ◽  
Author(s):  
Jean-Benoit Morin ◽  
Pedro Jiménez-Reyes ◽  
Matt Brughelli ◽  
Pierre Samozino
Keyword(s):  
Body Mass ◽  
Power Output ◽  
Lower Limb ◽  
Force Plate ◽  
Computation Method ◽  
Jump Height ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Sports Science ◽  
Force Velocity

Lower limb maximal power output (Pmax) is a key physical component of performance in many sports. During squat jump (SJ) and countermovement jump (CMJ) tests, athletes produce high amounts of mechanical work over a short duration to displace their body mass (i.e. the dimension of mechanical power). Thus, jump height has been frequently used by the sports science and medicine communities as an indicator of Pmax. However, in this article, we contended that SJ and CMJ height are in fact poor indicators of Pmax in trained populations. To support our opinion, we first detailed why, theoretically, jump height and Pmax are not fully related. Specifically, we demonstrated that individual body mass, distance of push-off, optimal loading and force-velocity characteristics confound the jump height-Pmax relationship. We also discussed the poor relationship between SJ or CMJ height and Pmax measured with a force plate based on data reported in the literature, which added to our own experimental evidence.Finally, we discussed the limitations of existing practical solutions (regression-based estimation equations and allometric scaling), and advocated using a valid, reliable and simple field-based procedure to compute individual Pmax directly from jump height, body mass and push-off distance. The latter may allow researchers and practitioners to reduce bias in their assessment of Pmax by using jump height as an input with a simple yet accurate computation method, and not as the first/only variable of interest.

Push recovery control for the underactuated lower extremity exoskeleton based on improved capture point concept

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jiaqi Zhang ◽  
Ming Cong ◽  
Dong Liu ◽  
Yu Du ◽  
Hongjiang Ma
Keyword(s):  
Lower Extremity ◽  
Ankle Joint ◽  
Lower Limb ◽  
Biped Robot ◽  
Lower Limbs ◽  
Simple Method ◽  
Content Type ◽  
Torsion Spring ◽  
Balance Ability ◽  
Capture Point

Purpose The purpose of this paper is to use a simple method to enhance the ability of lower limb exoskeletons to restore balance under large interference conditions and to solve the problem that biped robot stability criterion cannot be fully applied to the underactuated lower limb exoskeletons. Design/methodology/approach The method used in this paper is to construct an underactuated lower extremity exoskeleton ankle joint with a torsion spring. Based on the constructed exoskeleton, the linear inverted torsion spring pendulum model is proposed, and the traditional capture point (CP) concept is optimized. Findings The underactuated exoskeleton ankle joint with torsion springs, combined with the improved CP concept, can effectively reduce the forward stepping distance under the same interference condition, which is equivalent to enhancing the balance ability of the lower extremity exoskeleton. Originality/value The contribution of this paper is to enhance the balance ability of the exoskeleton of the lower limbs under large interference conditions. The torsion spring is used as the exoskeleton ankle joint, and the traditional CP concept is optimized according to the constructed exoskeleton.

scholarly journals Influence of the Physical Training on Muscle Function and Walking Distance in Symptomatic Peripheral Arterial Disease in Elderly

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Katarzyna Kropielnicka ◽  
Wioletta Dziubek ◽  
Katarzyna Bulińska ◽  
Małgorzata Stefańska ◽  
Joanna Wojcieszczyk-Latos ◽  
...  
Keyword(s):  
Intermittent Claudication ◽  
Physical Training ◽  
Lower Limb ◽  
Training Group ◽  
Walking Distance ◽  
Nordic Walking ◽  
Group Iii ◽  
Exercise Rehabilitation ◽  
Force Velocity ◽  
Group Ii

Introduction. A typical symptom of chronic lower-limb ischaemia is lower-limb pain, which occurs during walking forcing the patient to stop, intermittent claudication (IC). Exercise rehabilitation is the basic form of treatment for these patients. Aim. The aim of this study was to compare the effectiveness of three types of physical training programmes conducted over a 12-week period in patients with chronic lower-limb arterial insufficiency. Materials and Methods. Ninety-five people qualified for the 3-month supervised motor rehabilitation programme, conducted three times a week. The respondents were assigned to three types of rehabilitation programmes using a pseudo-randomization method: Group I (TW), subjects undertaking treadmill walking training; Group II (NW), subjects undertaking Nordic walking training; Group III (RES+NW), subjects undertaking resistance and Nordic walking training. Treadmill test, 6 Minute Walk Test (6MWT), and isokinetic test were repeated after 3 months of rehabilitation, which 80 people completed. Results. Combined training (RES+NW) is more effective than Nordic walking alone and supervised treadmill training alone for improving ankle force-velocity parameters (p<0.05) in patients with intermittent claudication. Each of the proposed exercise rehabilitation programmes increased walking distance of patients with intermittent claudication (p<0.05), especially in 6MWT (p=0.001). Significant relationships of force-velocity parameters are observed in the maximum distance obtained in 6MWT, both in Group III (RES + NW) and in Group II (NW) at the level of moderate and strong correlation strength, which indicates that if the lower limbs are stronger the walking distance achieved in 6MWT is longer. Conclusions. Given both the force-velocity parameters and the covered distance, the training RES + NW gives the most beneficial changes compared to training TW alone and NW alone. All types of training increased walking distance, which is an important aspect of the everyday functioning of people with IC.

scholarly journals Where does the One-Repetition Maximum Exist on the Force-Velocity Relationship in Squat?

2017 ◽  
Vol 38 (13) ◽  
pp. 1035-1043 ◽  
Author(s):  
Jean Rivière ◽  
Jérémy Rossi ◽  
Pedro Jimenez-Reyes ◽  
Jean-Benoit Morin ◽  
Pierre Samozino
Keyword(s):  
Lower Limb ◽  
Goodness Of Fit ◽  
Reaction Force ◽  
Squat Jump ◽  
Repetition Maximum ◽  
Velocity Relationship ◽  
Force Velocity ◽  
The Difference ◽  
The One ◽  
The Individual

AbstractThe aim was to determine the position of the one-repetition maximum (1RM) squat point on the force-velocity (F-V) relationship obtained during squat jump (SJ). Ten healthy athletes performed a 1RM squat during which ground reaction force and lower-limb extension velocity were measured, and six loaded SJs to determine individual F-V relationship. The goodness of fit of the linear F-V relationship with or without the 1RM point was tested. The vertical and horizontal coordinates were determined relative to the theoretical maximal force (F0) and the highest loaded SJ (load of 44.5±4.6% 1RM). The goodness of fit of the individual F-V relationship did not differ with or without the 1RM condition, even if the 1RM point was slightly below the curve (−5±5%, P=0.018). The 1RM point can be considered as a point of the F-V relationship. The velocity (0.22±0.05 m.s−1) of the 1RM point corresponded to ~30% of the velocity reached during the highest loaded SJ. The force developed in the 1RM condition was ~16% higher than during the highest loaded SJ and ~11% lower than F0. This finding underlines the difference between F0 and the 1RM condition.

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