Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique

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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The Relationship Between Vertical Ground Reaction Force, Loading Rate, and Sound Characteristics During a Single-Leg Landing

Journal of Sport Rehabilitation ◽

10.1123/jsr.2018-0260 ◽

2020 ◽

Vol 29 (5) ◽

pp. 541-546

Author(s):

Caroline Lisee ◽

Tom Birchmeier ◽

Arthur Yan ◽

Brent Geers ◽

Kaitlin O’Hagan ◽

...

Keyword(s):

Ground Reaction Force ◽

Loading Rate ◽

Reaction Force ◽

Measurement Techniques ◽

Sound Frequency ◽

Clinical Population ◽

Vertical Ground Reaction Force ◽

Vertical Ground ◽

The Relationship ◽

Linear Loading

Context: Landing kinetic outcomes are associated with injury risk and may be persistently altered after anterior cruciate ligament injury or reconstruction. However, it is challenging to assess kinetics clinically. The relationship between sound characteristics and kinetics during a limited number of functional tasks has been supported as a potential clinical alternative. Objective: To assess the relationship between kinetics and sound characteristics during a single-leg landing task. Design: Observational Setting: Laboratory. Participants: There was total of 26 healthy participants (15 males/11 females, age = 24.8 [3.6] y, height = 176.0 [9.1] cm, mass = 74.9 [14.4] kg, Tegner Activity Scale = 6.1 [1.1]). Intervention: Participants completed single-leg landings onto a force plate while audio characteristics were recorded. Main Outcome Measures: Peak vertical ground reaction force, linear loading rate, instantaneous loading rate, peak sound magnitude, sound frequency were measured. Means and SDs were calculated for each participant’s individual limbs. Spearman rho correlations were used to assess the relationships between audio characteristics and kinetic outcomes. Results: Peak sound magnitude was positively correlated with normalized peak vertical ground reaction force (ρ = .486, P = .001); linear loading rate (ρ = .491, P = .001); and instantaneous loading rate (ρ = .298, P = .03). Sound frequency was negatively correlated with instantaneous loading rate (ρ = −.444, P = .001). Conclusions: Peak sound magnitude may be more helpful in providing feedback about an individual’s normalized vertical ground reaction force and linear loading rate, and sound frequency may be more helpful in providing feedback about instantaneous loading rate. Further refinement in sound measurement techniques may be required before these findings can be applied in a clinical population.

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A 6-Week Transition to Maximal Running Shoes Does Not Change Running Biomechanics

The American Journal of Sports Medicine ◽

10.1177/0363546519826086 ◽

2019 ◽

Vol 47 (4) ◽

pp. 968-973 ◽

Cited By ~ 4

Author(s):

J.J. Hannigan ◽

Christine D. Pollard

Keyword(s):

Ground Reaction Force ◽

Loading Rate ◽

Impact Force ◽

Reaction Force ◽

Vertical Ground Reaction Force ◽

Risk Of Injury ◽

Impact Peak ◽

Running Shoes ◽

Vertical Ground ◽

The Impact

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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Association between increase in vertical ground reaction force loading rate and pain level in women with patellofemoral pain after a patellofemoral joint loading protocol

The Knee ◽

10.1016/j.knee.2018.03.009 ◽

2018 ◽

Vol 25 (3) ◽

pp. 398-405 ◽

Cited By ~ 8

Author(s):

Ronaldo Valdir Briani ◽

Marcella Ferraz Pazzinatto ◽

Marina Cabral Waiteman ◽

Danilo de Oliveira Silva ◽

Fábio Mícolis de Azevedo

Keyword(s):

Ground Reaction Force ◽

Patellofemoral Joint ◽

Loading Rate ◽

Reaction Force ◽

Patellofemoral Pain ◽

Pain Level ◽

Joint Loading ◽

Vertical Ground Reaction Force ◽

Force Loading ◽

Vertical Ground

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Computational Methods Used in the Determination of Loading Rate: Experimental and Clinical Implications

Journal of Applied Biomechanics ◽

10.1123/jab.15.4.404 ◽

1999 ◽

Vol 15 (4) ◽

pp. 404-417 ◽

Cited By ~ 7

Author(s):

C. Mark Woodard ◽

Margaret K. James ◽

Stephen P. Messier

Keyword(s):

Difference Method ◽

Ground Reaction Force ◽

Loading Rate ◽

Reaction Force ◽

Vertical Force ◽

Vertical Ground Reaction Force ◽

Central Difference ◽

Symptomatic Knee Osteoarthritis ◽

Central Difference Method ◽

Vertical Ground

Our purpose was to compare methods of calculating loading rate to the first peak vertical ground reaction force during walking and provide a rationale for the selection of a loading rate algorithm in the analysis of gait in clinical and research environments. Using vertical ground reaction force data collected from 15 older adults with symptomatic knee osteoarthritis and 15 healthy controls, we: (a) calculated loading rate as the first peak vertical force divided by the time from touchdown until the first peak; (b) calculated loading rate as the slope of the least squares regression line using vertical force and time as the dependent and independent variables, respectively; (c) calculated loading rate over discrete intervals using the Central Difference method; and (d) calculated loading rate using vertical force and lime data representing 20% and 90% of the first peak vertical force. The largest loading rate, which may be of greatest clinical importance, occurred when loading rates were calculated using the fewest number of data points. The Central Difference method appeared to maximize our ability to detect differences between healthy and pathologic cohorts. Finally, there was a strong correlation between methods, suggesting that all four methods are acceptable. However, if maximizing the chances of detecting differences between groups is of primary importance, the Central Difference method appears superior.

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Effectiveness of Insole Colour on Impact Loading and Lower-Limb Kinematics When Running at Preferred and Nonpreferred Speeds

Journal of Healthcare Engineering ◽

10.1155/2021/8947433 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Yi Wang ◽

Wing-Kai Lam ◽

Lok-Yee Pak ◽

Charis K.-W. Wong ◽

Mohammad F. Tan ◽

...

Keyword(s):

Impact Loading ◽

Ground Reaction Force ◽

Lower Limb ◽

Repeated Measures ◽

Loading Rate ◽

Reaction Force ◽

Human Perception ◽

Movement Variability ◽

Mean Values ◽

Maximum Loading

While colour of red can play a significant role in altering human perception and performances, little is known about its perceptual-motor effect on running mechanics. This study examined the effects of variations in insole colours on impact forces, ankle kinematics, and trial-to-trial reliability at various running speeds. Sixteen male recreational runners ran on instrumented treadmill at slow (90%), preferred (100%), and fast (110%) running speeds when wearing insoles in red, blue, and white colours. We used synchronized force platform and motion capturing system to measure ground reaction force, ankle sagittal and frontal kinematics, and movement variability. A two-way (colour x speed) ANOVA with repeated measures was performed with Bonferroni adjusted post hoc comparisons, with alpha set at 0.05. Data analyses indicated that participants demonstrated higher impact and maximum loading rate of ground reaction force, longer stride length, shorter contact time, and smaller touchdown ankle inversion as well as larger ankle sagittal range of motion (RoM), but smaller frontal RoM in fast speed as compared with preferred P < 0.05 and slow speeds P < 0.001 . Although insole colour had minimal effect on mean values of any tested variables P > 0.05 , participants wearing red-coloured orthoses showed higher coefficient of variation values for maximum loading rate than wearing blue insoles P = 0.009 . These results suggest that running at faster speed would lead to higher impact loading and altered lower-limb mechanics and that colour used on the tops of insoles influences the wearers’ movement repeatability, with implications for use of foot insole in running.

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A Forefoot Strike Requires the Highest Forces Applied to the Foot Among Foot Strike Patterns

Sports Medicine International Open ◽

10.1055/s-0042-122017 ◽

2017 ◽

Vol 01 (02) ◽

pp. E37-E42 ◽

Cited By ~ 2

Author(s):

Satoru Hashizume ◽

Toshio Yanagiya

Keyword(s):

Achilles Tendon ◽

Ground Reaction Force ◽

Reaction Force ◽

Moment Arm ◽

Moment Arms ◽

Joint Reaction Forces ◽

Force Moment ◽

Foot Strike ◽

Reaction Forces ◽

Joint Reaction

AbstractGround reaction force is often used to predict the potential risk of injuries but may not coincide with the forces applied to commonly injured regions of the foot. This study examined the forces applied to the foot, and the associated moment arms made by three foot strike patterns. 10 male runners ran barefoot along a runway at 3.3 m/s using forefoot, midfoot, and rearfoot strikes. The Achilles tendon and ground reaction force moment arms represented the shortest distance between the ankle joint axis and the line of action of each force. The Achilles tendon and joint reaction forces were calculated by solving equations of foot motion. The Achilles tendon and joint reaction forces were greatest for the forefoot strike (2 194 and 3 137 N), followed by the midfoot strike (1 929 and 2 853 N), and the rearfoot strike (1 526 and 2 394 N). The ground reaction force moment arm was greater for the forefoot strike than for the other foot strikes, and was greater for the midfoot strike than for the rearfoot strike. Meanwhile, there were no differences in the Achilles tendon moment arm among all foot strikes. These differences were attributed mainly to differences in the ground reaction force moment arm among the three foot strike patterns.

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Can We Decrease Floor Impact Noise by Changing Walking Patterns? - a Preliminary Report

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181321651153 ◽

2021 ◽

Vol 65 (1) ◽

pp. 1176-1179

Author(s):

Woojin Yoon ◽

Yujin Kwon ◽

Jaehyun Yoon ◽

Seobin Choi ◽

Gwanseob Shin

Keyword(s):

Preliminary Report ◽

Loading Rate ◽

Impact Force ◽

Gait Pattern ◽

Vertical Loading ◽

Apartment Buildings ◽

Impact Noise ◽

Impact Peak ◽

Foot Strike ◽

Do So

Floor impact noise from the footsteps of neighbors is one of the major social problems among people living in apartment buildings. In this laboratory environment, walking patterns and impact force on the floor were quantified from seventeen young adults while they were walking normally and quietly to investigate how the voluntary quiet walking to reduce the footstep noise would be different from the normal walking. Eight out of the 17 participants walked with a rearfoot strike pattern, and the rest (9 participants) changed their gait pattern to a non-rearfoot foot strike pattern when asked to walk quietly. Both groups showed decreases in impact peak and vertical loading rate, but the magnitude of the decrements was greater for the participants who walked with the non-rearfoot strike pattern. The preliminary result of this ongoing study suggests that people may not walk quietly even they believe to do so, and it warrants further studies to investigate more effective and easy-to-conduct walking strategies to address the floor impact noise issue of apartment buildings.

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Clinical application of foot strike run retraining for military service members with chronic knee pain

BMJ Military Health ◽

10.1136/bmjmilitary-2021-001789 ◽

2021 ◽

pp. bmjmilitary-2021-001789

Author(s):

Brittney Mazzone ◽

A Yoder ◽

R Condon ◽

S Farrokhi

Keyword(s):

Knee Pain ◽

Rating Scale ◽

Loading Rate ◽

Military Training ◽

Reaction Force ◽

Training Session ◽

Service Members ◽

Chronic Knee Pain ◽

Foot Strike

IntroductionMilitary training is associated with a high incidence of knee pain. Conversion from a rearfoot to non-rearfoot strike during running is effective at reducing knee pain in research environments. The purpose of this report was to demonstrate run retraining as a clinical intervention for service members with knee pain.MethodsSixteen service members with running-related chronic knee pain underwent run retraining that converted foot strike from a rearfoot to a non-rearfoot strike using real-time visual feedback. The Lower Extremity Functional Scale (LEFS) and Numerical Pain Rating Scale (NPRS) for knee pain during running were assessed pretraining, at the final training session and at a 1-month follow-up. During running, foot inclination angle and vertical ground reaction force (VGRF) average loading rate were measured pretraining and at 1 month of follow-up.ResultsService members underwent 7.4±1.0 training sessions over the course of 15.8±4.6 days. LEFS improved by 8±6 points immediately after retraining, with an overall improvement of 10±6 points from pretraining to 1-month follow-up (p<0.01). NPRS improved by 2.0±0.4 points immediately after retraining, with an overall improvement of 2.0±0.4 points from pretraining to 1-month follow-up (p<0.01). Conversion to a non-rearfoot strike pattern was apparent at follow-up for all but two patients. VGRF average loading rate decreased by 56%±17% (p<0.01) from pretraining to 1-month follow-up.ConclusionsKnee pain and function improved as a result of non-rearfoot strike run retraining, which supports the clinical use of this evidence-based intervention.

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Altered Vertical Ground Reaction Force Components While Walking in Individuals With Chronic Ankle Instability

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.2018-0117 ◽

2020 ◽

Vol 25 (1) ◽

pp. 27-30

Author(s):

Erik A. Wikstrom ◽

Kyeongtak Song ◽

Kimmery Migel ◽

Chris J. Hass

Keyword(s):

Ground Reaction Force ◽

Loading Rate ◽

Ankle Instability ◽

Reaction Force ◽

Chronic Ankle Instability ◽

Vertical Ground Reaction Force ◽

Time To Peak ◽

Vertical Ground ◽

Force Components

Aberrant loading is a mechanism by which individuals with chronic ankle instability (CAI) may negatively impact cartilage health and therefore long-term health outcomes. We aimed to quantify walking vertical ground reaction force (vGRF) component differences between those with and without CAI. Participants (n = 36) walked barefoot overground at a self-selected comfortable pace. Normalized peak vGRF, time to peak vGRF, and normalized loading rate were calculated. Higher normalized loading rates (CAI: 5.69 ± 0.62 N/BW/s; controls: 5.30 ± 0.44 N/BW/s, p = .034) and less time to peak vGRF (CAI: 1.48 ± 0.18 s; controls: 1.62 ± 0.16 s, p = .018) were observed in those with CAI. In conclusion, those with CAI demonstrate a higher normalized loading rate and less time to peak vGRF compared to controls.

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