Ground-Reaction Forces during Form Skipping and Running

2005 ◽  
Vol 14 (4) ◽  
pp. 338-345 ◽  
Author(s):  
Sam T. Johnson ◽  
Grace M. Golden ◽  
John A. Mercer ◽  
Brent C. Mangus ◽  
Mark A. Hoffman
Keyword(s):  
Outcome Measures ◽  
Healthy Subjects ◽  
College Athletes ◽  
Sports Injury ◽  
Research Center ◽  
Ground Reaction Forces ◽  
Type Design ◽  
Male College ◽  
Reaction Forces ◽  
Injury Research

Context:Form skipping has been used to help injured athletes progress to running. Because little research has been done on form-skipping mechanics, its justification as a progression to running exercises is unclear.Objective:To compare ground-reaction forces (GRF) during form skipping and running in healthy subjects at clinically relevant speeds, 1.75 m/s and 3.83 m/s, respectively.Design:Dependentttests (α= .05).Setting:Sports-injury research center.Participants:9 male college athletes (age 20 ± 1.33 years, mass 848.4 ± 43.24 N, height 1.80 ± 0.07 m).Main Outcome Measures:Average (Fzavg) and maximum (Fzmax) vertical GRF and (Fy) braking impulse were compared.Results:FzavgandFzmaxwere greater during running than during form skipping (P< .05). Braking impulses were not different (P> .05).Conclusions:It appears thatFz, but not theFy, GRF might explain why form skipping might be an appropriate progression to running.

Augmented Feedback Reduces Ground Reaction Forces in the Landing Phase of the Volleyball Spike Jump

2008 ◽  
Vol 17 (2) ◽  
pp. 148-159 ◽  
Author(s):  
John B. Cronin ◽  
Eadric Bressel ◽  
Loren Finn
Keyword(s):  
Body Weight ◽  
Outcome Measures ◽  
Collegiate Athletes ◽  
Ground Reaction Forces ◽  
Single Session ◽  
Augmented Feedback ◽  
Type Design ◽  
Division 1 ◽  
Before And After ◽  
Reaction Forces

Context:Frequency and magnitude of ground reaction forces (GRF) have been implicated in causing injuries such as “jumpers knee.”Objective:To investigate whether a single session of augmented feedback concerning landing technique would decrease GRF.Design:Pretest posttest experimental design.Setting:University biomechanics laboratory.Participants:Fifteen female Division 1 intercollegiate volleyball players.Intervention:Participants were required to land on a force platform after spiking a volleyball from a four-step approach before and after an intervention involving visual and aural augmented feedback on correct jumping and landing technique.Main Outcome Measures:Mediolateral (ML), anterioposterior (AP), and vertical (V) GRF normalized to body weight (BW).Results:Augmented feedback was found to significantly (P = 0.01) decrease VGRF by 23.6% but not ML (25%, P = 0.16) and AP (4.9%, P = 0.40) peak GRF.Conclusions:A single session of augmented feedback may be effective in reducing VGRF in collegiate athletes.

Effects of Altering Intensity during 1-MHz Ultrasound Treatment on Increasing Triceps Surae Temperature

2004 ◽  
Vol 13 (4) ◽  
pp. 275-286 ◽  
Author(s):  
Phillip O. Burr ◽  
Timothy J. Demchak ◽  
Mitchell L. Cordova ◽  
Christopher D. Ingersoll ◽  
Marcus B. Stone
Keyword(s):  
Healthy Volunteers ◽  
Outcome Measures ◽  
Research Laboratory ◽  
Sports Injury ◽  
Ultrasound Treatment ◽  
Triceps Surae ◽  
Physiological Effects ◽  
Type Design ◽  
Injury Research ◽  
Optimal Heating

Context:It has been suggested that to obtain optimal physiological effects of heating, musculoskeletal temperature (TEMP) should be elevated 3 °C above baseline and maintained for at least 5 min.Objective:To identify a multi-intensity ultrasound protocol that will achieve optimal heating.Design:1 × 2 between-subjects.Setting:Sports-injury research laboratory.Participants:20 healthy volunteers.Interventions:A 2.5-min treatment at 2.4 W/cm2 immediately followed by a 7.5-min treatment at 1.0 W/cm2 (T1) and a 10-min treatment at 1.5 W/cm2 (T2).Outcome Measures:TEMP change during the first 2.5 min of ultrasound treatment (°C), time the TEMP was ≥3 °C above baseline during and after the treatment.Results:T1 increased TEMP during the first 2.5 min of the ultrasound treatment (3.22 ± 1.25 °C) more than T2 did (1.68 ± 0.72 °C). No difference was found for the remaining measures.Conclusions:The multi-intensity protocol (2.4 W/cm2 and 1.0 W/cm2) did not result in optimal heating.

The Effects of Uni- and Bilateral Fatigue on Postural and Power Tasks

2013 ◽  
Vol 29 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Paulo H. Marchetti ◽  
Maria I.V. Orselli ◽  
Marcos Duarte
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Lower Limbs ◽  
Quiet Standing ◽  
Ground Reaction Forces ◽  
Before And After ◽  
Reaction Forces ◽  
The Mean

The aim of this study was to investigate the effects of unilateral and bilateral fatigue on both postural and power bipedal tasks. Ten healthy subjects performed two tasks: bipedal quiet standing and a maximal bipedal counter-movement jumping before and after unilateral (with either the dominant or nondominant lower limb) and bilateral (with both lower limbs) fatigue. We employed two force plates (one under each lower limb) to measure the ground reaction forces and center of pressure produced by subjects during the tasks. To quantify the postural sway during quiet standing, we calculated the resultant center of pressure (COP) speed and COP area of sway, as well as the mean weight distribution between lower limbs. To quantify the performance during the countermovement jumping, we calculated the jump height and the peak force of each lower limb. We observed that both unilateral and bilateral fatigue affected the performance of maximal voluntary jumping and standing tasks and that the effects of unilateral and bilateral fatigue were stronger in the dominant limb than in the nondominant limb during bipedal tasks. We conclude that unilateral neuromuscular fatigue affects both postural and power tasks negatively.

The Effect of Textured Insoles on Postural Control in Double and Single Limb Stance

2007 ◽  
Vol 16 (4) ◽  
pp. 363-372 ◽  
Author(s):  
Dawn M. Corbin ◽  
Joseph M. Hart ◽  
Patrick O. McKeon ◽  
Christopher D. Ingersoll ◽  
Jay Hertel
Keyword(s):  
Postural Control ◽  
Outcome Measures ◽  
Healthy Subjects ◽  
Crossover Trial ◽  
Center Of Pressure ◽  
Control Measures ◽  
Eyes Closed ◽  
Type Design ◽  
Afferent Information ◽  
Balance Trials

Context:Increased plantar cutaneous afferent information may improve postural control.Objective:To compare postural control measures between balance conditions with and without textured insoles.Design:crossover trial.Setting:Research Laboratory.Patients or Other Participants:33 healthy subjects (27.4 ± 9.1yrs, 172.6 ± 10.3 cm, 75.4 ± 16.4 kg).Intervention(s):Subjects performed 24, 10-second bipedal and unilateral stance balance trials with eyes opened and eyes closed, with and without a textured insole in subjects’ shoes.Main Outcome Measures:Average velocity and area of center of pressure (COP) excursions.Results:We observed an interaction among balance conditions during bilateral stance, but not during unilateral stance. On average, subjects exhibited greater area and velocity of COP excursions with eyes closed compared to eyes opened. Significant differences in area and velocity of COP excursions were observed during bilateral stance only when subjects were not wearing textured insoles. There were no significant differences while subjects balanced in bilateral stance with textured insoles.Conclusions:Increased afferent information from textured insoles improves postural control in bilateral stance.

scholarly journals Gait in male trans-tibial amputees: A comparative study with healthy subjects in relation to walking speed

1994 ◽  
Vol 18 (2) ◽  
pp. 68-77 ◽  
Author(s):  
Y. Hermodsson ◽  
C. Ekdahl ◽  
B. M. Persson ◽  
G. Roxendal
Keyword(s):  
Healthy Subjects ◽  
Walking Speed ◽  
Systemic Disease ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Ground Reaction Forces ◽  
Walking Ability ◽  
Gait Performance ◽  
Reaction Forces ◽  
Stance Duration

Walking speed, stance duration and ground reaction forces were studied with the use of a stable force platform (Kistler) in 24 male trans-tibial amputees and 12 healthy subjects matched for sex and age. The aim of the study was to compare the gait performance of two groups with unilateral trans-tibial amputations for either vascular disease or trauma and also to compare the results of the two groups with the results of a group of healthy subjects. Multiple linear regression analysis was used to compare the stance duration and the ground reaction forces in relation to walking speed. The vascular and traumatic amputees had significantly reduced walking speeds compared with the healthy subjects, 0.85±0.2 m/s and 0.99±0.2 m/s. respectively, as compared to 1.42±0.2 m/s. By comparing the vascular and traumatic amputees with the healthy subjects in relation to walking speed, it was shown that the gait performance of the vascular amputee differed from that of the traumatic amputee, a difference that was not caused by the reduced walking speed. The active forces during push off on both the healthy (p = 0.02) and the prosthetic leg (p = 0.003) in the trauma group were not found in the vascular group. This disparity could be an effect of the systemic disease. It may be argued that the results of this study contribute to the understanding of the reduced walking ability of the vascular amputee and should be borne in mind when planning rehabilitation.

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.

The Effects of a Multimodal Rehabilitation Program on Symptoms and Ground-Reaction Forces in Runners With Patellofemoral Pain Syndrome

2016 ◽  
Vol 25 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Jean-Francois Esculier ◽  
Laurent J. Bouyer ◽  
Jean-Sébastien Roy
Keyword(s):  
Motor Control ◽  
Outcome Measures ◽  
Lower Limb ◽  
Pain Syndrome ◽  
Patellofemoral Pain ◽  
Rehabilitation Program ◽  
Isometric Strength ◽  
Ground Reaction Forces ◽  
Vertical Loading ◽  
Reaction Forces

Context:Patellofemoral pain (PFP) is one of the most frequent running-related injuries. However, few interventions taking into consideration the specificity of running have been shown to be effective in runners with PFP.Objective:To evaluate the effects of a multimodal rehabilitation program including lower-limb-strengthening/motor-control exercises, advice on running biomechanics, and symptoms management on symptoms, strength, and ground-reaction forces in runners with PFP.Design:Pre- to post- quasi-experimental.Setting:Gait-analysis laboratory and private physical therapy clinic.Participants:21 runners with PFP (34.1 ± 6.0 y old, symptoms duration 38.1 ± 45.5 mo).Intervention:An 8-wk multimodal rehabilitation program including lower-limb- and core-strengthening and motor-control exercises, as well as advice on running gait and symptoms management.Main Outcome Measures:The Activities of Daily Living Scale of the Knee Outcome Survey (KOS-ADLS) questionnaire and visual analog scales for usual pain (VAS-U), worst pain (VAS-W), and pain during running (VAS-R) were used to assess changes in symptoms and function. Vertical ground-reaction forces (VGRF) during running and lower-limb isometric strength were also measured.Results:Statistically and clinically significant improvements (P < .001) were reported on KOS-ADLS (+17.8 pts), VAS-U (−19.2 pts), VAS-W (−28.7 pts), and VAS-R (−32.2 pts) after the intervention. No significant changes in isometric strength were observed. The instantaneous vertical loading rate was decreased after the intervention (P = .002), and this reduction was correlated with changes in KOS-ADLS scores (P = .028).Conclusion:This multimodal intervention was successful in reducing pain and improving function of runners with PFP. However, no significant changes in lower-limb strength were observed. It appears that changes in VGRF combined with appropriate training advice could explain the clinical outcomes.

Stance limb ground reaction forces in high functioning stroke and healthy subjects during gait initiation

2015 ◽  
Vol 30 (7) ◽  
pp. 689-695 ◽  
Author(s):  
Sheena Sharma ◽  
Angus J.C. McMorland ◽  
James W. Stinear
Keyword(s):  
Healthy Subjects ◽  
Gait Initiation ◽  
Ground Reaction Forces ◽  
High Functioning ◽  
Reaction Forces

scholarly journals Assessment of Gait Kinetics Using Triaxial Accelerometers

2014 ◽  
Vol 30 (5) ◽  
pp. 668-674 ◽  
Author(s):  
Emma Fortune ◽  
Melissa M.B. Morrow ◽  
Kenton R. Kaufman
Keyword(s):  
Physical Activity ◽  
Bone Health ◽  
Healthy Subjects ◽  
Ground Reaction Forces ◽  
Free Living ◽  
Dynamic Activity ◽  
Loading Rates ◽  
Reaction Forces ◽  
Vertical Accelerations ◽  
Health Field

Repeated durations of dynamic activity with high ground reaction forces (GRFs) and loading rates (LRs) can be beneficial to bone health. To fully characterize dynamic activity in relation to bone health, field-based measurements of gait kinetics are desirable to assess free-living lower-extremity loading. The study aims were to determine correlations of peak vertical GRF and peak vertical LR with ankle peak vertical accelerations, and of peak resultant GRF and peak resultant LR with ankle peak resultant accelerations, and to compare them to correlations with tibia, thigh, and waist accelerations. GRF data were collected as ten healthy subjects (26 [19–34] years) performed 8–10 walking trials at velocities ranging from 0.19 to 3.05 m/s while wearing ankle, tibia, thigh, and waist accelerometers. While peak vertical accelerations of all locations were positively correlated with peak vertical GRF and LR (r2 > .53, P < .001), ankle peak vertical accelerations were the most correlated (r2 > .75, P < .001). All peak resultant accelerations were positively correlated with peak resultant GRF and LR (r2 > .57, P < .001), with waist peak resultant acceleration being the most correlated (r2 > .70, P < .001). The results suggest that ankle or waist accelerometers give the most accurate peak GRF and LR estimates and could be useful tools in relating physical activity to bone health.

Sign in / Sign up

Export Citation Format

Share Document