The high frequency component of the vertical ground reaction force is a valid surrogate measure of the impact peak

Background: A recent study suggested that maximal running shoes may increase the impact force and loading rate of the vertical ground-reaction force during running. It is currently unknown whether runners will adapt to decrease the impact force and loading rate over time. Purpose: To compare the vertical ground-reaction force and ankle kinematics between maximal and traditional shoes before and after a 6-week acclimation period to the maximal shoe. Study Design: Controlled laboratory study. Methods: Participants ran in a traditional running shoe and a maximal running shoe during 2 testing sessions 6 weeks apart. During each session, 3-dimensional kinematics and kinetics were collected during overground running. Variables of interest included the loading rate, impact peak, and active peak of the vertical ground-reaction force, as well as eversion and dorsiflexion kinematics. Two-way repeated measures analyses of variance compared data within participants. Results: No significant differences were observed in any biomechanical variable between time points. The loading rate and impact peak were higher in the maximal shoe. Runners were still everted at toe-off and landed with less dorsiflexion, on average, in the maximal shoe. Conclusion: Greater loading rates and impact forces were previously found in maximal running shoes, which may indicate an increased risk of injury. The eversion mechanics observed in the maximal shoes may also increase the risk of injury. A 6-week transition to maximal shoes did not significantly change any of these measures. Clinical Relevance: Maximal running shoes are becoming very popular and may be considered a treatment option for some injuries. The biomechanical results of this study do not support the use of maximal running shoes. However, the effect of these shoes on pain and injury rates is unknown.

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Vertical ground reaction force analysis during gait with unstable shoes

Fisioterapia em Movimento ◽

10.1590/0103-5150.028.003.ao04 ◽

2015 ◽

Vol 28 (3) ◽

pp. 459-466

Author(s):

Giulia Pereira ◽

Aluísio Otavio Vargas Avila ◽

Rudnei Palhano

Keyword(s):

Ground Reaction Force ◽

Reaction Force ◽

Force Plate ◽

Vertical Ground Reaction Force ◽

Significant Difference ◽

Vertical Ground ◽

The Subject ◽

Unstable Shoes ◽

The Right ◽

The Impact

AbstractIntroduction Footwear is no longer just an accessory but also a protection for the musculoskeletal system, and its most important characteristic is comfort.Objectives This study aims to identify and to analyze the vertical ground reaction force in barefoot women and women with unstable shoes.Methodology Five women aged 25 ± 4 years old and mass of 50 ± 7 kg participated in this study. An AMTI force plate was used for data acquisition. The 10 trials for each situation were considered valid where the subject approached the platform with the right foot and at the speed of 4 km/h ± 5%. The instable shoe of this study is used in the practice of physical activity.Results The results showed that the first peak force was higher for the footwear situation, about 5% and significant differences between the barefoot and footwear situation. This significant difference was in the first and second peaks force and in the time of the second peak.Conclusion The values showed that the footwear absorbs approximately 45% of the impact during gait.

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Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern

Journal of Applied Biomechanics ◽

10.1123/jab.16.2.210 ◽

2000 ◽

Vol 16 (2) ◽

pp. 210-218 ◽

Cited By ~ 101

Author(s):

Dorsey S. Williams ◽

Irene S. McClay ◽

Kurt T. Manal

Keyword(s):

Lower Extremity ◽

Ground Reaction Force ◽

Injury Risk ◽

Reaction Force ◽

Three Dimensional ◽

Vertical Ground Reaction Force ◽

Running Performance ◽

Vertical Ground ◽

The Impact

Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.

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Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

Journal of Applied Physiology ◽

10.1152/japplphysiol.00925.2018 ◽

2019 ◽

Vol 126 (5) ◽

pp. 1315-1325 ◽

Cited By ~ 3

Author(s):

Andrew B. Udofa ◽

Kenneth P. Clark ◽

Laurence J. Ryan ◽

Peter G. Weyand

Keyword(s):

Ground Reaction Force ◽

Lower Limb ◽

Reaction Force ◽

Ground Reaction Forces ◽

Vertical Ground Reaction Force ◽

Time Patterns ◽

Foot Strike ◽

Reaction Forces ◽

Vertical Ground ◽

Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

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Agreement of spatio-temporal gait parameters between a vertical ground reaction force decomposition algorithm and a motion capture system

Gait & Posture ◽

10.1016/j.gaitpost.2015.10.007 ◽

2016 ◽

Vol 43 ◽

pp. 257-264 ◽

Cited By ~ 6

Author(s):

Louis-Nicolas Veilleux ◽

Maxime Raison ◽

Frank Rauch ◽

Maxime Robert ◽

Laurent Ballaz

Keyword(s):

Motion Capture ◽

Ground Reaction Force ◽

Reaction Force ◽

Decomposition Algorithm ◽

Motion Capture System ◽

Vertical Ground Reaction Force ◽

Gait Parameters ◽

Vertical Ground ◽

Spatio Temporal ◽

Force Decomposition

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The effect of total hip and hip resurfacing arthroplasty on vertical ground reaction force and impulse symmetry during a sit-to-stand task

Clinical Biomechanics ◽

10.1016/j.clinbiomech.2014.09.008 ◽

2014 ◽

Vol 29 (10) ◽

pp. 1164-1169 ◽

Cited By ~ 6

Author(s):

N. Caplan ◽

S. Stewart ◽

S. Kashyap ◽

P. Banaszkiewicz ◽

A. St Clair Gibson ◽

...

Keyword(s):

Ground Reaction Force ◽

Reaction Force ◽

Hip Resurfacing ◽

Vertical Ground Reaction Force ◽

Hip Resurfacing Arthroplasty ◽

Total Hip ◽

Resurfacing Arthroplasty ◽

Sit To Stand ◽

Vertical Ground

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Carrying loads with springy poles

Journal of Applied Physiology ◽

10.1152/jappl.1991.71.3.1119 ◽

1991 ◽

Vol 71 (3) ◽

pp. 1119-1122 ◽

Cited By ~ 37

Author(s):

R. Kram

Keyword(s):

Oxygen Consumption ◽

Ground Reaction Force ◽

Oxygen Consumption Rate ◽

Consumption Rate ◽

Reaction Force ◽

Load Carriage ◽

Vertical Ground Reaction Force ◽

Suspension Systems ◽

Vertical Ground ◽

Male Subjects

People throughout Asia use springy bamboo poles to carry the loads of everyday life. These poles are a very compliant suspension system that allows the load to move along a nearly horizontal path while the person bounces up and down with each step. Could this be an economical way to carry loads inasmuch as no gravitational work has to be done to lift the load repeatedly? To find out, an experiment was conducted in which four male subjects ran at 3.0 m/s on a motorized treadmill with no load and while carrying a load equal to 19% body wt with compliant poles. Oxygen consumption rate, vertical ground reaction force, and the force exerted by the load on the shoulders were measured. Oxygen consumption rate increased by 22%. The same increase has previously been observed when loads are carried with a backpack. Thus compliant poles are not a particularly economical method of load carriage. However, pole suspension systems offer important advantages: they minimize peak shoulder forces and loading rates. In addition, the peak vertical ground reaction force is only slightly increased above unloaded levels when loads are carried with poles.

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385 EFFECT OF RATE OF ECCENTRIC EXERCISE ON PLASMA SUBSTANCE P AND PEAK VERTICAL GROUND REACTION FORCE

Medicine & Science in Sports & Exercise ◽

10.1249/00005768-199405001-00386 ◽

1994 ◽

Vol 26 (Supplement) ◽

pp. S69

Author(s):

P. L Flynn ◽

M. Sothmann ◽

P. Schot ◽

A. Snydor

Keyword(s):

Substance P ◽

Eccentric Exercise ◽

Ground Reaction Force ◽

Reaction Force ◽

Vertical Ground Reaction Force ◽

Vertical Ground

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The Relationship Between Vertical Loadrates and Tibial Acceleration Across Footstrike Patterns

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00200 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0020 ◽

Cited By ~ 1

Author(s):

Irene Davis ◽

Todd Hayano ◽

Adam Tenforde

Keyword(s):

Impact Loading ◽

Ground Reaction Force ◽

Reaction Force ◽

Force Plate ◽

Correlation Coefficients ◽

Strongly Correlated ◽

Vertical Ground Reaction Force ◽

Vertical Ground ◽

Tibial Acceleration ◽

The Relationship

Category: Other Introduction/Purpose: While the etiology of injuries is multifactorial, impact loading, as measured by the loadrate of the vertical ground reaction force has been implicated. These loadrates are typically measured with a force plate. However, this limits the measure of impacts to laboratory environments. Tibial acceleration, another measure of running impacts, is considered a surrogate for loadrate. It can be measured using new wearable technology that can be used in a runner’s natural environment. However, the correlation between tibial acceleration measured from mobile devices and vertical ground reaction force loadrates, measured from forceplates, is unknown. The purpose of this study was to determine the correlation between vertical and resultant loadrates to vertical and resultant tibial acceleration across different footstrike patterns (FSP) in runners. Methods: The study involved a sample of convenience made up of 169 runners (74 F, 95 M; age: 38.66±13.08 yrs) presenting at a running injury clinic. This included 25 habitual forefoot strike (FFS), 17 midfoot strike (MFS) and 127 rearfoot strike (RFS) runners. Participants ran on an instrumented treadmill (average speed 2.52±0.25 m/s), with a tri-axial accelerometer attached at the left distal medial tibia. Only subjects running with pain <3/10 on a VAS scale during the treadmill run were included to reduce the confounding effect of pain. Vertical average, vertical instantaneous and resultant instantaneous loadrates (VALR, VILR and RILR) and peak vertical and resultant tibial accelerations (VTA, RTA) were averaged for 8 consecutive left steps. Correlation coefficients (r) were calculated between tibial accelerations and loadrates. Results: All tibial accelerations were significantly correlated across all loadrates, with the exception of RTA with VILR for FFS (Table 1) which was nearly significant (p=0.068). Correlations ranged from 0.37-0.82. VTA was strongly correlated with all loadrates (r = 0.66). RTA was also strongly correlated with both loadrates for RFS and MFS, but only moderately correlated with loadrates for FFS (r = 0.47). Correlations were similar across the different loadrates (VALR, VILR, RILR). Conclusion: The stronger correlation between vertical tibial acceleration and all loadrates (VALR, VILR, RILR) suggests that it may be the best surrogate for loadrates when studying impact loading in runners.

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