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

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
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.

The Effects of Cryotherapy on Ground-Reaction Forces Produced during a Functional Task

2000 ◽  
Vol 9 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Stephen J. Kinzey ◽  
Mitchell L. Cordova ◽  
Kevin J. Gallen ◽  
Jason C. Smith ◽  
Justin B. Moore
Keyword(s):  
Outcome Measures ◽  
Ground Reaction Force ◽  
Repeated Measures ◽  
Vertical Jump ◽  
Weight Bearing ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Reaction Forces ◽  
Vertical Ground

Objective:To determine whether a standard 20-min ice-bath (10°C) immersion of the leg alters vertical ground-reaction-force components during a 1 -legged vertical jump.Design:A 1 × 5 factorial repeated-measures model was used.Setting:The Applied Biomechanics Laboratory at The University of Mississippi.Participants:Fifteen healthy and physically active subjects (age = 22.3 ± 2.1 years, height = 177.3 ± 12.2 cm, mass = 76.3 ± 19.1 kg) participated.Intervention:Subjects performed 25 one-legged vertical jumps with their preferred extremity before (5 jumps) and after (20 jumps) a 20-min cold whirlpool to the leg. The 25 jumps were reduced into 5 sets of average trials.Main Outcome Measures:Normalized peak and average vertical ground-reaction forces, as well as vertical impulse obtained using an instrumented force platform.Results:Immediately after cryotherapy (sets 2 and 3), vertical impulse decreased (P= .01); peak vertical ground-reaction force increased (set 2) but then decreased toward baseline measures (P= .02). Average vertical ground-reaction force remained unchanged (P>.05).Conclusions:The authors advocate waiting approximately 15 min before engaging in activities that require the production of weight-bearing explosive strength or power.

scholarly journals The Effects of Posture on the Three-Dimensional Gait Mechanics of Human Walking in Comparison to Bipedal Chimpanzees

2021 ◽  
Author(s):  
Russell T. Johnson ◽  
Matthew C. O'Neill ◽  
Brian R. Umberger
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Three Dimensional ◽  
Bipedal Walking ◽  
Human Walking ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Gait Mechanics ◽  
Reaction Forces ◽  
Vertical Ground

Humans walk with an upright posture on extended limbs during stance and with a double-peaked vertical ground reaction force. Our closest living relatives, chimpanzees, are facultative bipeds that walk with a crouched posture on flexed, abducted hind limbs and with a single-peaked vertical ground reaction force. Differences in human and bipedal chimpanzee three-dimensional kinematics have been well quantified; however, it is unclear what the independent effects of using a crouched posture are on three-dimensional gait mechanics for humans, and how they compare with chimpanzees. Understanding the relationships between posture and gait mechanics, with known differences in morphology between species, can help researchers better interpret the effects of trait evolution on bipedal walking. We quantified pelvis and lower limb three-dimensional kinematics and ground reaction forces as humans adopted a series of upright and crouched postures and compared them with data from bipedal chimpanzee walking. Human crouched posture gait mechanics were more similar to bipedal chimpanzee gait than normal human walking, especially in sagittal plane hip and knee angles. However, there were persistent differences between species, as humans walked with less transverse plane pelvis rotation, less hip abduction, and greater peak horizontal ground reaction force in late stance than chimpanzees. Our results suggest that human crouched posture walking reproduces only a small subset of the characteristics of three-dimensional kinematics and ground reaction forces of chimpanzee walking, with the remaining differences likely due in large part to the distinct musculoskeletal morphologies of humans and chimpanzees.

Effects of trial repetition, limb side, intraday and inter-week variation on vertical and craniocaudal ground reaction forces in clinically normal Labrador Retrievers

2011 ◽  
Vol 24 (06) ◽  
pp. 435-444 ◽  
Author(s):  
B. Nordquist ◽  
J. Fischer ◽  
S. Y. Kim ◽  
S. M. Stover ◽  
T. Garcia-Nolen ◽  
...  
Keyword(s):  
Data Collection ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Reaction Forces ◽  
Pelvic Limb ◽  
Vertical Ground ◽  
Labrador Retrievers ◽  
Force Data

SummaryObjectives: To document the contributions of trial repetition, limb side, and intraday and inter-week measurements on variation in vertical and craniocaudal ground reaction force data.Methods: Following habituation, force and time data were collected for all four limbs of seven Labrador Retrievers during sets of five valid trot trials. Each set was performed twice daily (morning and afternoon), every seven days for three consecutive weeks. A repeated measures analysis of variance was used to determine the effects of limb, trial, intraday, and inter-week factors on ground reaction force data for the thoracic and pelvic limbs.Results: Of the four factors evaluated, variation due to trial repetition had the largest magnitude of effect on ground reaction forces. Trial within a set of data had an effect on all craniocaudal, but not vertical, ground reaction force variables studied, for the thoracic limbs. The first of five trials was often different from later trials. Some thoracic limb and pelvic limb variables were different between weeks. A limb side difference was only apparent for pelvic limb vertical ground reaction force data. Only pelvic limb craniocaudal braking variables were different between sets within a day.Discussion and clinical significance: When controlling for speed, handler, gait, weight and dog breed, variation in ground reaction forces mainly arise from trial repetition and inter-week data collection. When using vertical peak force and impulse to evaluate treatment, trial repetition and inter-week data collection should have minimal effect of the data.

scholarly journals An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
AmirAli Jafarnezhadgero ◽  
Elahe Mamashli ◽  
Urs Granacher
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Exercise Program ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Significant Group ◽  
Heel Contact ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Post Hoc

BackgroundThe prevalence of diabetes worldwide is predicted to increase from 2.8% in 2000 to 4.4% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility.ObjectiveWe aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO2max), ground reaction forces, and muscle activities during walking in patients with moderate DN.MethodsSixty male and female individuals aged 45–65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40–55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO2max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s.ResultsNo statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO2max (p < 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p < 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001–0.037; d = 0.56–1.53). For IG, post-hoc analyses showed decreases in peak lateral (p < 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p < 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001–0.044; d = 0.54–0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p < 0.001; d = 1.28).ConclusionsThis study demonstrated that an endurance-dominated exercise program has the potential to improve VO2max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics.

Vertical Ground Reaction Force Redistribution During Experimentally Induced Shoulder Lameness in Dogs

1994 ◽  
Vol 07 (04) ◽  
pp. 154-157 ◽  
Author(s):  
R. M. McLaughlin ◽  
J. K. Roush ◽  
Dominique Griffon
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Total Force ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Vertical Ground Reaction Force ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces ◽  
Surgically Induced

SummaryThe redistribution of vertical ground reaction forces after surgically induced forelimb lameness was evaluated in five Greyhounds at the walk. Vertical ground reaction forces were measured by force plate analysis before, three days, and seven days after a craniolateral approach to the shoulder was performed unilaterally in each dog.At day # 3, peak vertical force was significantly decreased in the operated forelimbs and in the ipsilateral hindlimbs. Peak vertical force was significantly increased in the contralateral fore- and hindlimbs. The total peak vertical force applied to both forelimbs did not change, nor did the total force applied to both hindlimbs. At day # 7, peak vertical force in each of the four limbs had returned to preoperative levels. Results of this study document the redistribution of ground reaction forces (at the walk) between the four limbs in the dog after an acute, surgically induced forelimb lameness.The redistribution of ground reaction force was evaluated in five Greyhounds before and during forelimb lameness. Lameness was induced by a craniolateral approach to one shoulder in each dog. At day # 3 after surgery, peak vertical force was decreased in the operated forelimbs and ipsilateral hindlimbs. Peak vertical force was increased in the contralateral fore- and hindlimbs. The distribution of ground reaction force in the four limbs returned to preoperative values seven days after surgery.

scholarly journals Force-Time Waveform Shape Reveals Countermovement Jump Strategies of Collegiate Athletes

Sports ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 159
Author(s):  
Trent M. Guess ◽  
Aaron D. Gray ◽  
Brad W. Willis ◽  
Matthew M. Guess ◽  
Seth L. Sherman ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
National Collegiate Athletic Association ◽  
Reaction Force ◽  
Collegiate Athletes ◽  
Principal Component ◽  
Countermovement Jump ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Force Time ◽  
Time Waveform

The purpose of this study was to relate the shape of countermovement jump (CMJ) vertical ground reaction force waveforms to discrete parameters and determine if waveform shape could enhance CMJ analysis. Vertical ground reaction forces during CMJs were collected for 394 male and female collegiate athletes competing at the National Collegiate Athletic Association (NCAA) Division 1 and National Association of Intercollegiate Athletics (NAIA) levels. Jump parameters were calculated for each athlete and principal component analysis (PCA) was performed on normalized force-time waveforms consisting of the eccentric braking and concentric phases. A K-means clustering of PCA scores placed athletes into three groups based on their waveform shape. The overall average waveforms of all athletes in each cluster produced three distinct vertical ground reaction force waveform patterns. There were significant differences across clusters for all calculated jump parameters. Athletes with a rounded single hump shape jumped highest and quickest. Athletes with a plateau at the transition between the eccentric braking and concentric phase (amortization) followed by a peak in force near the end of the concentric phase had the lowest jump height and slowest jump time. Analysis of force-time waveform shape can identify differences in CMJ strategies in collegiate athletes.

scholarly journals Pirouette Vertical Ground Reaction Force of Ballet Dancers and Non-Dancers

2020 ◽  
Vol 14 (2) ◽  
pp. 53-61
Author(s):  
Cynthia Hiraga ◽  
Camila Siriani ◽  
Paulo Ricardo Higassiaraguti Rocha ◽  
Débora Alves Souza ◽  
José Angelo Barela
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Vertical Force ◽  
Ballet Dancer ◽  
Vertical Ground Reaction Force ◽  
Ballet Dancers ◽  
Dance Training ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Initial Impulse

BACKGROUND: Different amounts of force are needed to produce an effective turn for the pirouette, especially vertical force. AIM: To examine the vertical force produced by the supporting leg during the execution of a pirouette en dehors of ballet dancer and non-dancer participants. METHOD: The participants included five ballet dancers who composed the ballet dancer group and eight girls without previous experience of dance training who composed the non-dancer group. The participants were invited to execute the pirouette en dehors on a force platform with each leg as the supporting leg. Two-way analyses of variance were used to test vertical reaction forces between the two groups over the preferred and non-preferred leg. RESULTS: Among the three vertical forces measured in the present study, the maximum vertical peak for the initial impulse was significantly higher for the ballet dancers compared to the non-dancer girls. The minimum vertical force and maximum vertical peak for the final impulse were similar between both groups. CONCLUSION: The results suggest that the initial vertical force may be critical to the pirouette en dehors, determining proficient execution of this movement in ballet dancers.

A Finite Element Analysis of a Subject Specific Single-Leg Drop Landing at Varied Heights

2011 ◽  
Author(s):  
Chi-Yin Tse ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri ◽  
Paul K. Canavan
Keyword(s):  
Knee Flexion ◽  
Reaction Force ◽  
Acl Injury ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Element Analysis ◽  
Drop Landing ◽  
Subject Specific ◽  
Reaction Forces ◽  
Vertical Ground

The pathomechanics of knee anterior cruciate ligament (ACL) injury related to the female athlete is of high interest due to the high incidence of injury compared to males participating in the same sport. The mechanisms of ACL injury are still not completely understood, but it is known that single-leg landings, stopping and cutting at high velocity are some of the non-contact mechanisms that are causing these injuries. This study analyzed a subject specific analysis of a single-leg drop landing that was performed by a female subject at 60%, 80% and 100% of her maximum vertical jump. The femur, tibia, articular cartilage, and menisci were modeled as 3-D structures and the data collected from the motion analysis was used to obtain the knee joint contact stresses in finite element analysis (FEA). The four major ligaments of the knee were modeled as non-linear springs. Material properties of previously published studies were used to define the soft tissue structures. The articular cartilage was defined as isotropic elastic and the menisci were defined as transverse isotropic elastic. Two different styles of single-leg landings were compared to one another, resembling landing from a basketball rebound. The first landing style, single-leg arms up (SLAU), produced larger knee flexion angles at peak ground reaction forces, while single-leg arms across (SLAX) landings produced higher peak vertical ground reaction forces along with lower knee flexion angles. The mean peak vertical ground reaction force was 2.9–3.5 bodyweight for SLAU landings, while they were 3.0–3.8 for SLAX landings. The time to peak vertical ground reaction force with SLAU landings were 69 ms (60%), 60 ms (80%), and 55 ms (100%); SLAX landings were 61 ms (60%), 61 ms (80%), and 51 ms (100%).

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