scholarly journals Mechanics, energetics and implementation of grounded running technique: a narrative review

2020 ◽  
Vol 6 (1) ◽  
pp. e000963
Author(s):  
Sheeba Davis ◽  
Aaron Fox ◽  
Jason Bonacci ◽  
Fiddy Davis
Keyword(s):  
Postural Stability ◽  
Injury Risk ◽  
Metabolic Cost ◽  
Duty Factor ◽  
Vertical Oscillation ◽  
Leg Stiffness ◽  
Speed Range ◽  
Impact Attenuation ◽  
Acute Increase ◽  
Recreational Runners

Grounded running predominantly differs from traditional aerial running by having alternating single and double stance with no flight phase. Approximately, 16% of runners in an open marathon and 33% of recreational runners in a 5 km running event adopted a grounded running technique. Grounded running typically occurs at a speed range of 2–3 m·s−1, is characterised by a larger duty factor, reduced vertical leg stiffness, lower vertical oscillation of the centre of mass (COM) and greater impact attenuation than aerial running. Grounded running typically induces an acute increase in metabolic cost, likely due to the larger duty factor. The increased duty factor may translate to a more stable locomotion. The reduced vertical oscillation of COM, attenuated impact shock, and potential for improved postural stability may make grounded running a preferred form of physical exercise in people new to running or with low loading capacities (eg, novice overweight/obese, elderly runners, rehabilitating athletes). Grounded running as a less impactful, but metabolically more challenging form, could benefit these runners to optimise their cardio-metabolic health, while at the same time minimise running-related injury risk. This review discusses the mechanical demands and energetics of grounded running along with recommendations and suggestions to implement this technique in practice.

scholarly journals Leg Stiffness, Joint Stiffness, and Running-Related Injury: Evidence From a Prospective Cohort Study

2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110112
Author(s):  
John J. Davis ◽  
Allison H. Gruber
Keyword(s):  
Cohort Study ◽  
Injury Risk ◽  
Joint Stiffness ◽  
Injury Rate ◽  
Knee Stiffness ◽  
Ankle Stiffness ◽  
Leg Stiffness ◽  
Wide Range ◽  
Recreational Runners

Background: The spring-like behavior of the leg and the joints of the lower body during running are thought to influence a wide range of physiologic and mechanical phenomena, including susceptibility to overuse injury. If leg and joint stiffness are associated with running-related injuries, altering joint or leg stiffness may be a useful avenue for injury rehabilitation and injury prevention programs. Purpose: To test the associations between running-related injury and leg stiffness, knee stiffness, and ankle stiffness in a prospective study of recreational runners. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 49 healthy recreational runners took part in a year-long study. Participants completed a 3-dimensional kinematic and kinetic biomechanical assessment at baseline and reported training volume and injury status in a weekly survey during the follow-up period. Relationships between stiffness and injury were assessed at the level of individual legs (n = 98) using spline terms in Cox proportional hazards models. Results: During follow-up, 23 participants (29 legs) sustained injury. The median time to injury was 27 weeks (53.27 hours of training). Relative injury rate as a function of knee stiffness displayed a weak and nonsignificant U-shaped curve ( P = .187-.661); ankle and leg stiffness displayed no discernable associations with relative injury rate (leg stiffness, P = .215-.605; ankle stiffness, P = .419-.712). Conclusion: Leg and joint stiffness may not be important factors in the development of running-related injuries. Moderate changes in leg and joint stiffness are unlikely to substantially alter injury risk.

Reduced prosthetic stiffness lowers the metabolic cost of running for athletes with bilateral transtibial amputations

2017 ◽  
Vol 122 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Owen N. Beck ◽  
Paolo Taboga ◽  
Alena M. Grabowski
Keyword(s):  
Lower Limb ◽  
Metabolic Cost ◽  
Ground Reaction Forces ◽  
Metabolic Rates ◽  
Distance Running ◽  
Cost Of Transport ◽  
Leg Stiffness ◽  
Metabolic Costs ◽  
In Series ◽  
Reaction Forces

Inspired by the springlike action of biological legs, running-specific prostheses are designed to enable athletes with lower-limb amputations to run. However, manufacturer’s recommendations for prosthetic stiffness and height may not optimize running performance. Therefore, we investigated the effects of using different prosthetic configurations on the metabolic cost and biomechanics of running. Five athletes with bilateral transtibial amputations each performed 15 trials on a force-measuring treadmill at 2.5 or 3.0 m/s. Athletes ran using each of 3 different prosthetic models (Freedom Innovations Catapult FX6, Össur Flex-Run, and Ottobock 1E90 Sprinter) with 5 combinations of stiffness categories (manufacturer’s recommended and ± 1) and heights (International Paralympic Committee’s maximum competition height and ± 2 cm) while we measured metabolic rates and ground reaction forces. Overall, prosthetic stiffness [fixed effect (β) = 0.036; P = 0.008] but not height ( P ≥ 0.089) affected the net metabolic cost of transport; less stiff prostheses reduced metabolic cost. While controlling for prosthetic stiffness (in kilonewtons per meter), using the Flex-Run (β = −0.139; P = 0.044) and 1E90 Sprinter prostheses (β = −0.176; P = 0.009) reduced net metabolic costs by 4.3–4.9% compared with using the Catapult prostheses. The metabolic cost of running improved when athletes used prosthetic configurations that decreased peak horizontal braking ground reaction forces (β = 2.786; P = 0.001), stride frequencies (β = 0.911; P < 0.001), and leg stiffness values (β = 0.053; P = 0.009). Remarkably, athletes did not maintain overall leg stiffness across prosthetic stiffness conditions. Rather, the in-series prosthetic stiffness governed overall leg stiffness. The metabolic cost of running in athletes with bilateral transtibial amputations is influenced by prosthetic model and stiffness but not height. NEW & NOTEWORTHY We measured the metabolic rates and biomechanics of five athletes with bilateral transtibial amputations while running with different prosthetic configurations. The metabolic cost of running for these athletes is minimized by using an optimal prosthetic model and reducing prosthetic stiffness. The metabolic cost of running was independent of prosthetic height, suggesting that longer legs are not advantageous for distance running. Moreover, the in-series prosthetic stiffness governs the leg stiffness of athletes with bilateral leg amputations.

Repeated Impacts Diminish the Impact Performance of Equestrian Helmets

2019 ◽  
Vol 28 (4) ◽  
pp. 368-372
Author(s):  
Carl G. Mattacola ◽  
Carolina Quintana ◽  
Jed Crots ◽  
Kimberly I. Tumlin ◽  
Stephanie Bonin
Keyword(s):  
Injury Risk ◽  
Head Injuries ◽  
The United States ◽  
Expanded Polystyrene ◽  
Head Acceleration ◽  
Safety Equipment ◽  
Impact Performance ◽  
Computed Tomography Scans ◽  
Impact Attenuation ◽  
The Impact

Context: During thoroughbred races, jockeys are placed in potentially injurious situations, often with inadequate safety equipment. Jockeys frequently sustain head injuries; therefore, it is important that they wear appropriately certified helmets. Objective: The goals of this study are (1) to perform impact attenuation testing according to ASTM F1163-15 on a sample of equestrian helmets commonly used by jockeys in the United States and (2) to quantify headform acceleration and residual crush after repeat impacts at the same location. Participants and Design: Seven helmet models underwent impact attenuation testing according to ASTM F1163-15. A second sample of each helmet model underwent repeat impacts at the crown location for a total of 4 impacts. Setting: Laboratory. Intervention: Each helmet was impacted against a flat and equestrian hazard anvil. Main Outcome Measures: Headform acceleration was recorded during all impact and computed tomography scans were performed preimpact and after impacts 1 and 4 on the crown to quantify liner thickness. Results: Four helmets had 1 impact that exceeded the limit of 300g. During the repeated crown impacts, acceleration remained below 300g for the first and second impacts for all helmets, while only one helmet remained below 300g for all impacts. Foam liner thickness was reduced between 5% and 39% after the first crown impact and between 33% and 70% after the fourth crown impact. Conclusions: All riders should wear a certified helmet and replace it after sustaining a head impact. Following an impact, expanded polystyrene liners compress, and their ability to attenuate head acceleration during subsequent impacts to the same location is reduced. Replacing an impacted helmet may reduce a rider’s head injury risk.

scholarly journals Postural Stability During Single-Leg Stance: A Preliminary Evaluation of Noncontact Lower Extremity Injury Risk

2016 ◽  
Vol 46 (8) ◽  
pp. 650-657 ◽  
Author(s):  
Bart Dingenen ◽  
Bart Malfait ◽  
Stefaan Nijs ◽  
Koen H.E. Peers ◽  
Styn Vereecken ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Postural Stability ◽  
Injury Risk ◽  
Lower Extremity Injury ◽  
Preliminary Evaluation ◽  
Extremity Injury ◽  
Single Leg Stance

Muscle Soreness during Running: Biomechanical and Physiological Considerations

1991 ◽  
Vol 7 (2) ◽  
pp. 125-137 ◽  
Author(s):  
Joseph Hamill ◽  
Patty S. Freedson ◽  
Priscilla M. Clarkson ◽  
Barry Braun
Keyword(s):  
Lower Extremity ◽  
Muscle Soreness ◽  
Plantar Flexion ◽  
Metabolic Cost ◽  
Analysis Data ◽  
Delayed Onset ◽  
Healthy Female ◽  
Recreational Runners ◽  
Global Parameters ◽  
Level Running

This study involved an 8-day protocol to determine the effects of delayed-onset muscle soreness (DOMS) on the mechanics of the lower extremity and on oxygen consumption during level running. On Day 1 the subjects, 10 healthy female recreational runners, were administered a treadmill max V̇O2test. They completed a 30-min downhill run on Day 3 to induce muscle soreness. On Days 2, 5, and 8 they completed a 15-min level run at a speed corresponding to 80% of V̇O2max. Subsequent to each run the subjects completed a muscle soreness questionnaire and a blood sample was taken for creatine kinase (CK) analysis. Data analysis revealed statistically significant between-day differences for perceived muscle soreness and CK activity. However, metabolic cost was not different between days. There were significant differences between days in maximum ankle support dorsiflexion and plantar flexion and maximum knee flexion during both support and swing. None of the global parameters describing the total stride produced significant differences between Days 2 and 5. Therefore DOMS appeared to have little effect on V̇O2and a small effect on the kinematics of the lower extremity.

scholarly journals Injury incidence and risk factors: a cohort study of 706 8-km or 16-km recreational runners

2019 ◽  
Vol 5 (1) ◽  
pp. e000489 ◽  
Author(s):  
Joan Dallinga ◽  
Rogier Van Rijn ◽  
Janine Stubbe ◽  
Marije Deutekom
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Cohort Study ◽  
Injury Risk ◽  
Significant Risk ◽  
Personal Characteristics ◽  
Significant Risk Factor ◽  
Baseline Survey ◽  
Injury Incidence ◽  
Recreational Runners

ObjectivesTo report (1) the injury incidence in recreational runners in preparation for a 8-km or 16-km running event and (2) which factors were associated with an increased injury risk.MethodsProspective cohort study in Amsterdam, the Netherlands. Participants (n=5327) received a baseline survey to determine event distance (8 km or 16 km), main sport, running experience, previous injuries, recent overuse injuries and personal characteristics. Three days after the race, they received a follow-up survey to determine duration of training period, running distance per week, training hours, injuries during preparation and use of technology. Univariate and multivariate regression models were applied to examine potential risk factors for injuries.Results1304 (24.5%) participants completed both surveys. After excluding participants with current health problems, no signed informed consent, missing or incorrect data, we included 706 (13.3%) participants. In total, 142 participants (20.1%) reported an injury during preparation for the event. Univariate analyses (OR: 1.7, 95% CI 1.1 to 2.4) and multivariate analyses (OR: 1.7, 95% CI 1.1 to 2.5) showed that injury history was a significant risk factor for running injuries (Nagelkerke R-square=0.06).ConclusionAn injury incidence for recreational runners in preparation for a running event was 20%. A previous injury was the only significant risk factor for running-related injuries.

Leg exoskeleton reduces the metabolic cost of human hopping

2009 ◽  
Vol 107 (3) ◽  
pp. 670-678 ◽  
Author(s):  
Alena M. Grabowski ◽  
Hugh M. Herr
Keyword(s):  
Metabolic Cost ◽  
Metabolic Energy ◽  
Metabolic Power ◽  
Metabolic Demand ◽  
Mass System ◽  
Leg Muscles ◽  
Single Leaf ◽  
Leg Stiffness ◽  
Reaction Forces ◽  
Linear Spring

During bouncing gaits such as hopping and running, leg muscles generate force to enable elastic energy storage and return primarily from tendons and, thus, demand metabolic energy. In an effort to reduce metabolic demand, we designed two elastic leg exoskeletons that act in parallel with the wearer's legs; one exoskeleton consisted of a multiple leaf (MLE) and the other of a single leaf (SLE) set of fiberglass springs. We hypothesized that hoppers, hopping on both legs, would adjust their leg stiffness while wearing an exoskeleton so that the combination of the hopper and exoskeleton would behave as a linear spring-mass system with the same total stiffness as during normal hopping. We also hypothesized that decreased leg force generation while wearing an exoskeleton would reduce the metabolic power required for hopping. Nine subjects hopped in place at 2.0, 2.2, 2.4, and 2.6 Hz with and without an exoskeleton while we measured ground reaction forces, exoskeletal compression, and metabolic rates. While wearing an exoskeleton, hoppers adjusted their leg stiffness to maintain linear spring-mass mechanics and a total stiffness similar to normal hopping. Without accounting for the added weight of each exoskeleton, wearing the MLE reduced net metabolic power by an average of 6% and wearing the SLE reduced net metabolic power by an average of 24% compared with hopping normally at frequencies between 2.0 and 2.6 Hz. Thus, when hoppers used external parallel springs, they likely decreased the mechanical work performed by the legs and substantially reduced metabolic demand compared with hopping without wearing an exoskeleton.

Reducing the metabolic energy of walking and running using an unpowered hip exoskeleton

2020 ◽  
Author(s):  
Tiancheng Zhou ◽  
Caihua Xiong ◽  
Juanjuan Zhang ◽  
Di Hu ◽  
Wenbin Chen ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Design Method ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Human Response ◽  
Speed Range ◽  
The Common ◽  
Spatio Temporal ◽  
Hip Flexion ◽  
Optimal Stiffness

Abstract Background: Walking and running are the most common means of locomotion in human daily life. People have made advances in developing separate exoskeletons to reduce metabolic rate of walking or running. However, the combined requirements of overcoming fundamental biomechanical differences between the two gaits and minimizing the metabolic penalty of exoskeleton mass make it challenging to develop an exoskeleton that can reduce the metabolic energy for both gaits. Here we show that the metabolic energy of both walking and running can be reduced by regulating the metabolic energy of hip flexion during the common energy consumption period of the two gaits using an unpowered hip exoskeleton. Methods: We analyzed metabolic rates, muscle activities and spatio-temporal parameters from 9 healthy subjects (mean s.t.d; 24.9 ± 3.7 years, 66.9 ± 8.7 kg, 1.76 ± 0.05 m) walking on a treadmill at the speed of 1.5 m×s -1 and running at speed of 2.5 m×s -1 with different spring stiffnesses. After obtaining the optimal spring stiffness, we recruited the participants to walk and run with the optimal stiffness spring at different speeds to demonstrate the generality of the proposed approach. Results: We found that the optimal exoskeleton spring stiffnesses for walking and running were 140 N×m Rad -1 and 210 N×m Rad -1 respectively, corresponding to 8.2% ± 1.5% (mean ± s.e.m, two-sided paired t-test: p < 0.01) and 9.1% ± 1.3% ( p < 0.01) metabolic reductions compared to walking/running without exoskeleton. The metabolic energy within tested speed range can be reduced with the assistance except for low speed walking (1.0 m s -1 ). Participants showed different changes in muscle activities with the assistance of proposed exoskeleton. Conclusions: This paper first demonstrated that metabolic cost of walking and running can be reduced using an unpowered hip exoskeleton to regulate metabolic energy of hip flexion. The design method based on analyzing the common energy consumption characteristics between gaits may inspire future exoskeletons that assist multiple gaits. The results of different changes in muscle activities provided a new insight of human response to the same assistive principle in different gaits (walking and running).

Sign in / Sign up

Export Citation Format

Share Document