Leg stiffness and stride frequency in human running

Farley, Claire T.; González, O

doi:10.1016/0021-9290(95)00029-1

Cited by 591 publications

(519 citation statements)

References 18 publications

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“…Adaptations in the chosen angle of attack similar to our findings has been observed during running for largely different animals (Farley et al 1993) and humans (Farley and Gonzalez, 1996).…”

Section: Comparison With Experimental Studiessupporting

confidence: 89%

“…In human, running at different stride frequencies for a given speed almost constant peak ground reaction forces were observed for largely different leg stiffness and angles of attack (Farley and Gonzalez, 1996). This supports our observation in Eq.…”

Section: Comparison With Experimental Studiessupporting

confidence: 88%

“…Blickhan (1989) and McMahon and Cheng (1990) introduced a simple spring-mass model to approximate this generally observed force pattern. This representation of the leg by a linear spring was successfully applied by biologists (Blickhan and Full, 1993;Farley et al, 1993;Farley and Gonzalez, 1996), sport scientists (Arampatzis et al, 1999;Seyfarth et al, 1999), and bioengineers (Herr, 1998) to describe and predict animal and human locomotion. However, there is only little known about the advantages of this type of leg operation.…”

Section: Introductionmentioning

confidence: 99%

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A movement criterion for running

Seyfarth

Geyer

Günther

et al. 2002

Journal of Biomechanics

425

382

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The adjustment of the leg during running was addressed using a spring-mass model with a fixed landing angle of attack. The objective was to obtain periodic movement patterns. Spring-like running was monitored by a one-dimensional stride-to-stride mapping of the apex height to identify mechanically stable fixed points.We found that for certain angles of attack, the system becomes self-stabilized if the leg stiffness was properly adjusted and a minimum running speed was exceeded. At a given speed, running techniques fulfilling a stable movement pattern are characterized by an almost constant maximum leg force. With increasing speed, the leg adjustment becomes less critical. The techniques predicted for stable running are in agreement with experimental studies.Mechanically self-stabilized running requires a spring-like leg operation, a minimum running speed and a proper adjustment of leg stiffness and angle of attack. These conditions can be considered as a movement criterion for running. r

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Section: Comparison With Experimental Studiessupporting

confidence: 89%

Section: Comparison With Experimental Studiessupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

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A movement criterion for running

Seyfarth

Geyer

Günther

et al. 2002

Journal of Biomechanics

425

382

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show abstract

“…Arampatzis et al, 1999), the predicted stiffness is far above the biological range, which, however, is no contradiction since humans do use flatter angles of attack in running (speed dependent, e.g. a 0 ¼ 60-70 ; Farley and Gonzalez (1996)). …”

Section: Quality Of Approximate Solutionmentioning

confidence: 93%

Spring-mass running: simple approximate solution and application to gait stability

Geyer

Seyfarth

Blickhan

2005

Journal of Theoretical Biology

249

232

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The planar spring-mass model is frequently used to describe bouncing gaits (running, hopping, trotting, galloping) in animal and human locomotion and robotics. Although this model represents a rather simple mechanical system, an analytical solution predicting the center of mass trajectory during stance remains open. We derive an approximate solution in elementary functions assuming a small angular sweep and a small spring compression during stance. The predictive power and quality of this solution is investigated for model parameters relevant to human locomotion. The analysis shows that (i), for spring compressions of up to 20% (angle of attack X60 ; angular sweep p60 ) the approximate solution describes the stance dynamics of the center of mass within a 1% tolerance of spring compression and 0:6 tolerance of angular motion compared to numerical calculations, and (ii), despite its relative simplicity, the approximate solution accurately predicts stable locomotion well extending into the physiologically reasonable parameter domain. (iii) Furthermore, in a particular case, an explicit parametric dependency required for gait stability can be revealed extending an earlier, empirically found relationship. It is suggested that this approximation of the planar spring-mass dynamics may serve as an analytical tool for application in robotics and further research on legged locomotion. r

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“…Leg-spring stiffness like CT and RSI further illustrates how the muscle tendon unit behaves during jumping. An increase in leg stiffness can be associated with increased leg cadence of a fast SSC activity, such as hopping and sprinting (2,15,16). In addition, it has been shown that sprinters have high legspring stiffness (9,22).…”

Section: Discussionmentioning

confidence: 99%

An Investigation Into the Recovery Process of a Maximum Stretch-Shortening Cycle Fatigue Protocol on Drop and Rebound Jumps

Comyns

Harrison

Hennessy

2011

Journal of Strength and Conditioning Research

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Comyns, TM, Harrison, AJ, and Hennessy, LK. An investigation into the recovery process of a maximum stretch-shortening cycle fatigue protocol on drop and rebound jumps. J Strength Cond Res 25(X): 000-000, 2011-The aim of this study was to investigate the recovery process of a maximal stretch-shortening cycle (SSC) fatigue workout on the biomechanical performance of drop jump (DJ) and rebound jump (RBJ) on a force sledge apparatus. Thirteen elite level rugby players performed sledge DJs and RBJs before and 15, 45, 120, and 300 seconds after a maximum SSC fatigue workout. Flight time, ground contact time (CT), peak force, reactive strength index (RSI), and leg-spring stiffness were the dependent variables. The DJ results showed that after 15 seconds recovery, there was a significant reduction in flight time (FT) (p , 0.01), RSI (p , 0.001), peak force (p , 0.01), and leg stiffness (p , 0.001). Similarly, the results for the RBJ indicated that the fatigue workout significantly reduced FT (p , 0.001), peak force (p , 0.01), RSI (p , 0.01), and significantly increased CT (p , 0.05) at the 15-second interval. The results also indicated a potentiation effect at the 300-second interval because of significant increases in RSI, peak force, and leg stiffness (p , 0.05) for the RBJ and significant increases in RSI (p , 0.05), peak force, and leg stiffness (p , 0.01) and a significant decrease in ground CT (p , 0.05) for the DJ. A maximal SSC fatigue workout had both an inhibiting and potentiating effect on DJ and RBJ performance depending on the recovery interval. The efficiency of the SSC function was reduced immediately after the cessation of the fatigue workout. A potentiation effect was evident for both jumps 300 seconds postfatigue.

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Leg stiffness and stride frequency in human running

Cited by 591 publications

References 18 publications

A movement criterion for running

A movement criterion for running

Spring-mass running: simple approximate solution and application to gait stability

An Investigation Into the Recovery Process of a Maximum Stretch-Shortening Cycle Fatigue Protocol on Drop and Rebound Jumps

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