Runners adjust leg stiffness for their first step on a new running surface

Ferris, Daniel P.; Liang, Kailine; Farley, Claire T.

doi:10.1016/s0021-9290(99)00078-0

Cited by 330 publications

(281 citation statements)

References 19 publications

Supporting

Mentioning

260

Contrasting

Unclassified

Order By: Relevance

“…The two players who preferred sandbased pitches have one as their home pitch. It appeared that some players adapted better than others to different surfaces, a finding supported by Ferris et al, 1999. The skill level aspect of play was mentioned by many, and it is possible that players with more experience of many surface types will have learned to adapt more than those with less experience.…”

Section: Pitch Propertiesmentioning

confidence: 81%

Human perceptions of artificial surfaces for field hockey

et al. 2005

View full text Add to dashboard Cite

Measuring the performance of a sports surface is typically derived from a series of field and laboratory tests that assess the playing properties under simulated game conditions. However, from a player's perspective their own comfort and confidence in the surface and its playing characteristics are equally if not more important. To date no comparative study to measure playing preference tests has been made. The aim of this research was to develop a suitable method for eliciting player perceptions of field hockey pitches and determine the key themes that players consider when assessing field hockey pitches. To elicit meaningful unbiased human perceptions of a playing surface, an individual subjective analysis was carried out, using interviews and inductive analysis of the recorded player statements. A qualitative analysis of elite hockey players (n = 22) was performed to obtain their perceptions immediately after a competitive match. The significant surface characteristics that emerged as part of an inductive analysis of their responses were grouped together and formed five general themes or dimensions: player performance, playing environment, pitch properties, ball interaction and player interaction. Each dimension was formed from a hierarchy of sub-themes. During the analysis, relationships between the dimensions were identified and a structured relationship model was produced to highlight each relationship. Players' responses suggested that they perceived differences between pitches and that the majority of players considered a 'hard' pitch with a 'low' ball bounce facilitating a 'fast' game speed was desirable. However, further research is required to understand the relative importance of each theme and to develop appropriate measurement strategies to quantify the relevant engineering properties of pitch materials.

show abstract

Section: Pitch Propertiesmentioning

confidence: 81%

Human perceptions of artificial surfaces for field hockey

et al. 2005

View full text Add to dashboard Cite

show abstract

“…We expect that differences in the metabolic cost of running on various surfaces are likely related to the k leg variations observed by Farley et al and Ferris et al (13,17,18). Specifically, we expect a less flexed knee to account for a reduction in metabolic cost (30), as well as an increase in k leg (3,18).…”

Section: In Their Groundbreaking Work Mcmahon and Greenementioning

confidence: 83%

“…This range of stiffnesses was selected to incorporate the range of McMahon and Greene's "tuned track" (29) and to extend the work of similar recent studies (16)(17)(18). We hypothesize that the metabolic cost of forward human running reaches a minimum when the k leg of the runner is maximized on surfaces of decreased stiffness.…”

Section: In Their Groundbreaking Work Mcmahon and Greenementioning

confidence: 99%

Energetics and mechanics of human running on surfaces of different stiffnesses

Kerdok

Biewener

McMahon

et al. 2002

Journal of Applied Physiology

305

246

View full text Add to dashboard Cite

. Energetics and mechanics of human running on surfaces of different stiffnesses. J Appl Physiol 92: 469-478, 2002; 10.1152/ japplphysiol.01164.2000.-Mammals use the elastic components in their legs (principally tendons, ligaments, and muscles) to run economically, while maintaining consistent support mechanics across various surfaces. To examine how leg stiffness and metabolic cost are affected by changes in substrate stiffness, we built experimental platforms with adjustable stiffness to fit on a force-plate-fitted treadmill. Eight male subjects [mean body mass: 74.4 Ϯ 7.1 (SD) kg; leg length: 0.96 Ϯ 0.05 m] ran at 3.7 m/s over five different surface stiffnesses (75.4, 97.5, 216.8, 454.2, and 945.7 kN/m). Metabolic, ground-reaction force, and kinematic data were collected. The 12.5-fold decrease in surface stiffness resulted in a 12% decrease in the runner's metabolic rate and a 29% increase in their leg stiffness. The runner's support mechanics remained essentially unchanged. These results indicate that surface stiffness affects running economy without affecting running support mechanics. We postulate that an increased energy rebound from the compliant surfaces studied contributes to the enhanced running economy. biomechanics; locomotion; leg stiffness; metabolic rate IN THEIR GROUNDBREAKING work, McMahon and Greene (29) investigated the effects of surface stiffness (k surf ) on running mechanics. Their study sought to determine whether it was possible to build a track surface that would enhance performance and decrease injury. Their work showed that a range of k surf values existed over which a runner's performance was enhanced by decreasing foot-ground contact time (t c ), decreasing the initial spike in peak vertical ground reaction force (f peak ), and increasing stride length. Tracks built within this enhanced performance range at Harvard University, Yale University, and Madison Square Garden have been shown to increase running speeds by 2-3% and to decrease running injuries by 50% (29). Despite the success of these "tuned tracks," the mechanisms underlying the performance enhancement are not clearly understood.A major assumption of McMahon and Greene's (29) was that the running leg and surface could be represented as a simple spring and mass (Fig.

show abstract

“…Surface compliance and damping can affect locomotion energetics and dynamics (Ferris et al, 1998;Ferris et al, 1999;Kerdok et al, 2002), as do surface inclines or declines (Margaria, 1976;Minetti et al, 1993). However, few studies have characterized the biomechanics and energetics of walking on uneven surfaces.…”

Section: Discussionmentioning

confidence: 99%

Biomechanics and energetics of walking on uneven terrain

Voloshina

Kuo

Daley

et al. 2013

Journal of Experimental Biology

207

186

View full text Add to dashboard Cite

Summary Walking on uneven terrain is more energetically costly than walking on smooth ground, but the biomechanical factors that contribute to this increase are unknown. To identify possible factors, we constructed an uneven terrain treadmill that allowed us to record biomechanical, electromyographic, and metabolic energetics data from human subjects. We hypothesized that walking on uneven terrain would increase step width and length variability, joint mechanical work, and muscle co-activation compared to walking on smooth terrain. We tested healthy subjects (N=11) walking at 1.0 m/s, and found that, when walking on uneven terrain with up to 2.5 cm variation, subjects decreased their step length by 4% and did not significantly change their step width, while both step length and width variability increased significantly (22% and 36%, respectively; p<0.05). Uneven terrain walking caused a 28% and 62% increase in positive knee and hip work, and a 26% greater magnitude of negative knee work (0.0106, 0.1078, and 0.0425 J/kg, respectively; p<0.05). Mean muscle activity increased in seven muscles in the lower leg and thigh (p<0.05). These changes caused overall net metabolic energy expenditure to increase by 0.73 W/kg (28%; p<0.0001). Much of that increase could be explained by the increased mechanical work observed at the knee and hip. Greater muscle co-activation could also contribute to increased energetic cost but to unknown degree. The findings provide insight into how lower limb muscles are used differently for natural terrain compared to laboratory conditions.

show abstract

Runners adjust leg stiffness for their first step on a new running surface

Cited by 330 publications

References 19 publications

Human perceptions of artificial surfaces for field hockey

Human perceptions of artificial surfaces for field hockey

Energetics and mechanics of human running on surfaces of different stiffnesses

Biomechanics and energetics of walking on uneven terrain

Contact Info

Product

Resources

About