scholarly journals The Relationship between Isometric Force-Time Characteristics and Dynamic Performance: A Systematic Review

Sports ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 63 ◽  
Author(s):  
Danny Lum ◽  
G. Gregory Haff ◽  
Tiago M. Barbosa
Keyword(s):  
Isometric Force ◽  
Dynamic Performance ◽  
Lower Limbs ◽  
Upper Body ◽  
Original Research ◽  
Dynamic Performances ◽  
Time Variables ◽  
Force Time ◽  
The Relationship ◽  
Body Dynamic

The purpose of this article was to review the data on the relationship between multi-joint isometric strength test (IsoTest) force-time characteristics (peak force, rate of force development and impulse) and dynamic performance that is available in the current literature. Four electronic databases were searched using search terms related to IsoTest. Studies were considered eligible if they were original research studies that investigated the relationships between multi-joint IsoTest and performance of dynamic movements; published in peer-reviewed journals; had participants who were athletes or active individuals who participate in recreational sports or resistance training, with no restriction on sex; and had full text available. A total of 47 studies were selected. These studies showed significant small to large correlations between isometric bench press (IBP) force-time variables and upper body dynamic performances (r2 = 0.221 to 0.608, p < 0.05) and significant small to very large correlation between isometric squat (ISqT) (r2 = 0.085 to 0.746, p < 0.05) and isometric mid-thigh pull (IMTP) (r2 = 0.120 to 0.941, p < 0.05) force-time variables with lower body dynamic performances. IsoTest force-time characteristics were shown to have small to very large correlations with dynamic performances of the upper and lower limbs as well as performance of sporting movements (r2 = 0.118 to 0.700, p < 0.05). These data suggest that IsoTest force-time characteristics provide insights into the force production capability of athletes which give insight into dynamic performance capabilities.

The Relationship Between Isometric Force-Time Curve Characteristics and Club Head Speed in Recreational Golfers

2012 ◽  
Vol 26 (10) ◽  
pp. 2685-2697 ◽  
Author(s):  
Brian K. Leary ◽  
Jason Statler ◽  
Britton Hopkins ◽  
Rachael Fitzwater ◽  
Tucker Kesling ◽  
...  
Keyword(s):  
Isometric Force ◽  
Time Curve ◽  
Club Head ◽  
Force Time ◽  
The Relationship ◽  
Recreational Golfers

The Relationship Between EMG-Time and Isometric Force-Time Curves

2002 ◽  
Vol 34 (5) ◽  
pp. 22
Author(s):  
Loren Z.F. Chiu ◽  
Andrew C. Fry ◽  
Brian K. Schilling ◽  
Lawrence W. Weiss ◽  
Richard B. Kreider
Keyword(s):  
Isometric Force ◽  
Force Time ◽  
The Relationship

Isometric Assessment of Muscular Function: The Effect of Joint Angle

1995 ◽  
Vol 11 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Aron J. Murphy ◽  
Greg J. Wilson ◽  
John F. Pryor ◽  
Robert U. Newton
Keyword(s):  
Bench Press ◽  
Joint Angle ◽  
Dynamic Performance ◽  
Muscle Mechanics ◽  
Upper Body ◽  
Joint Angles ◽  
Repetition Maximum ◽  
Muscular Function ◽  
And Performance ◽  
The Relationship

The purpose of this investigation was to determine the relationship between isometric measures of muscular function at two different joint angles and dynamic performance. Thirteen experienced weight trainers performed two isometric tests in a bench press position, at elbow angles of 90 and 120°. Performance was assessed by a one repetition maximum (1-RM) bench press and a series of upper body bench press throws at loads of 15, 30, and 60% of the 1-RM load. The results clearly show that changing the joint angle from 120 to 90° improved the relationship between most of the tests and performance by more than 100%, possibly due to differences in motor unit recruitment patterns and differing muscle mechanics (e.g., length-tension), at varying joint angles. It was suggested that the best angle at which to assess isometric function may be the joint angle at which peak force is developed in the performance of interest.

The Neuromuscular Qualities of Higher- and Lower-Level Mixed-Martial-Arts Competitors

2017 ◽  
Vol 12 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Lachlan P. James ◽  
Emma M. Beckman ◽  
Vincent G. Kelly ◽  
G. Gregory Haff
Keyword(s):  
Martial Arts ◽  
Bench Press ◽  
Isometric Force ◽  
Average Power ◽  
Dynamic Strength ◽  
Upper Body ◽  
Whole Body ◽  
Lower Body ◽  
Mixed Martial Arts ◽  
Body Dynamic

Purpose:To determine whether the maximal strength, impulse, and power characteristics of competitive mixed-martial-arts (MMA) athletes differ according to competition level.Methods:Twenty-nine male semiprofessional and amateur MMA competitors were stratified into either higher-level (HL) or lower-level (LL) performers on the basis of competition grade and success. The 1-repetition-maximum (1RM) squat was used to assess lower-body dynamic strength, and a spectrum of impulse, power, force, and velocity variables were evaluated during an incremental-load jump squat. In addition, participants performed an isometric midthigh pull (IMTP) and 1RM bench press to determine whole-body isometric force and upper-body dynamic strength capabilities, respectively. All force and power variables were expressed relative to body mass (BM).Results:The HL competitors produced significantly superior values across a multitude of measures. These included 1RM squat strength (1.84 ± 0.23 vs 1.56 ± 0.24 kg BM; P = .003), in addition to performance in the incremental-load jump squat that revealed greater peak power (P = .005–.002), force (P = .002–.004), and velocity (P = .002–.03) at each load. Higher measures of impulse (P = .01–.04) were noted in a number of conditions. Average power (P = .002–.02) and velocity (P = .01–.04) at all loads in addition to a series of rate-dependent measures were also superior in the HL group (P = .005–.02). The HL competitors’ 1RM bench-press values approached significantly greater levels (P = .056) than the LL group’s, but IMTP performance did not differ between groups.Conclusions:Maximal lower-body neuromuscular capabilities are key attributes distinguishing HL from LL MMA competitors. This information can be used to inform evidenced-based training and performance-monitoring practices.

Dynamic Performance Analysis of Locomotives Based on the Matching between Worn Wheel-Rail Profiles

2013 ◽  
Vol 748 ◽  
pp. 386-389
Author(s):  
Da Kui Wang ◽  
Jun Zhang ◽  
Xiu Juan Zhang ◽  
You Yi Sheng
Keyword(s):  
Dynamic Performance ◽  
Type I ◽  
Dynamic Performances ◽  
Wheel Profile ◽  
Dynamic Software ◽  
Pass Through ◽  
Set Up ◽  
Multi Body ◽  
Dynamic Performance Analysis ◽  
Body Dynamic

Wheel profiles in different abrasion stages are tracked and measured for locomotives SS4. They are then matched with rail profiles in the measured wear stability period. In order to contrast the wheel profiles in different abrasion stages, multi-body dynamic software named SIMPACK is adapted to set up a complete dynamics model of locomotives. The influence of wheel profiles in different abrasion stages on the dynamic performances of locomotives is simulated and analyzed. Analysis results state that locomotives using the wheel profiles of typeII have the good stability for their line operation. Locomotives using the wheel profiles of type I have the highest critical hunting speed of 223km/h, which is 54.8% larger than those of wheel profile JM3. When locomotives pass through curve tracks, the value of derailment factor for the wheel profiles of typeII is the smallest and achieves an excellent level, which explains that the wheel profiles of typeII can obtain the good curve negotiation performance.

scholarly journals The Inter-Session Reliability of Isometric Force-Time Variables and the Effects of Filtering and Starting Force

2019 ◽  
Vol 66 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Gavin L. Moir ◽  
Aaron Getz ◽  
Shala E. Davis ◽  
Mário Marques ◽  
Chad A. Witmer
Keyword(s):  
Body Mass ◽  
Isometric Force ◽  
Intraclass Correlation ◽  
Time Signal ◽  
Time Intervals ◽  
Temporal Shift ◽  
Back Squat ◽  
Time Variables ◽  
Force Time

AbstractThe purposes of the present study were to assess the inter-session reliability of force-time variables recorded during isometric back squats and also to assess the effects of applying a filter to the data prior to analysis and assess the effects of different starting force thresholds on the force-time variables. Eleven resistance trained men (age: 22.5 ± 1.9 years; body mass: 90.3 ± 13.5 kg) attended two sessions where they performed isometric squats on force plates allowing the determination of force-time variables of maximal isometric force (Fmax) and different measures of the rate of force development (RFD). The force-time variables were calculated from both raw and filtered force signals. The start of the force application was determined using force thresholds of 1% or 5% of body mass (BM). Inter-session reliability for the force-time measures was assessed by calculating the intraclass correlation coefficient (ICC) and the coefficient of variation (CV) of the measures. The ICC and CV ranged from 0.03 to 0.96 and 4.6 to 168%, respectively. The application of the filter significantly reduced Fmax and peak RFD (p < 0.004) and increased the reliability of the peak RFD. The use of the 5% BM threshold increased the magnitude of many of the RFD measures (p < 0.004) and resulted in slight improvements in the reliability of these measures although the resulting temporal shift in the force-time signal would preclude accurate assessment of the early phase of the RFD (< 100 ms). The use of a 1% BM starting force threshold without a filter is recommended when using the isometric back squat protocol presented here. Furthermore, the RFD calculated within specific time intervals is recommended

Mid-aortic syndrome: computed tomography angiography depicting extensive collateral circulation in an 11-year-old patient with thoracoabdominal aortic coarctation

VASA ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 132-135 ◽  
Author(s):  
Krohn ◽  
Gebauer ◽  
Hübler ◽  
Beck
Keyword(s):  
Computed Tomography ◽  
Computed Tomography Angiography ◽  
Collateral Circulation ◽  
Intestinal Ischemia ◽  
Clinical Presentation ◽  
Lower Limbs ◽  
Upper Body ◽  
Descending Aorta ◽  
Before And After ◽  
Blood Pressures

The mid-aortic syndrome is an uncommon clinical condition characterized by severe narrowing of the descending aorta, usually with involvement of its renal and visceral branches, presenting with uncontrollably elevated blood pressures of the upper body, renal and cardiac failure, intestinal ischemia, encephalopathy symptoms and claudication of the lower limbs, although clinical presentation is variable. In this article we report the case of an eleven-year-old patient with the initial diagnosis of a mid-aortic syndrome and present the computed tomography angiography pictures and reconstructions before and after surgical therapy.

Congenital Syphilis Simulating Bone Neoplasm in 2-Month Old Infant – Case Report

2017 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Case Report ◽  
Congenital Syphilis ◽  
Eosinophilic Granuloma ◽  
Osteolytic Lesion ◽  
Lower Limbs ◽  
Upper Body ◽  
Elective Cesarean Section ◽  
Distal Fibula ◽  
X Ray

Introduction: Congenital Syphilis (CS) occurs through the transplacental transmission of Treponema pallidum in inadequately treated or non-treated pregnant women, and is capable of severe consequences such as miscarriage, preterm birth, congenital disease and/or neonatal death. CS has been showing an increasing incidence worldwide, with an increase of 208% from 2009 to 2015 in Brazil. Case report: 2-month old infant receives care in emergency service due to edema of right lower limb with pain in mobilization. X-ray with osteolytic lesion in distal fibula. Infant was sent to the Pediatrics Oncology clinic. Perinatal data: 7 prenatal appointments, negative serology at 10 and 30 weeks of gestation. End of pregnancy tests were not examined and tests for mother’s hospital admission were not requested. Mother undergone elective cesarean section at 38 weeks without complications. During the pediatric oncologist appointment, patient showed erythematous-squamous lesions in neck and other scar-like lesions in upper body. A new X-ray of lower limbs showed lesions in right fibula with periosteal reaction associated with aggressive osteolytic lesion compromising distal diaphysis, with cortical bone rupture and signs of pathological fracture, suggestive of eosinophilic granuloma. She was hospitalized for a lesion biopsy. Laboratory tests: hematocrit: 23.1 / hemoglobin 7.7 / leukocytes 10,130 (without left deviation) / platelets 638,000 / Negative Cytomegalovirus IgG and IgM and Toxoplasmosis IgG and IgM / VDRL 1:128. Congenital syphilis diagnosis with skin lesions, bone alterations and anemia. Lumbar puncture: glucose 55 / total proteins 26 / VDRL non reagent / 13 leukocytes (8% neutrophils; 84% monomorphonuclear; 8% macrophages) and 160 erythrocytes / negative VDRL and culture. X-ray of other long bones, ophthalmological evaluation and abdominal ultrasound without alterations. Patient was hospitalized for 14 days for treatment with Ceftriaxone 100mg/kg/day, due to the lack of Crystalline Penicillin in the hospital. She is now under outpatient follow-up. Discussion: CS is responsible for high rates of morbidity and mortality. The ongoing increase of cases of this pathology reflects a severe health issue and indicates failures in policies for the prevention of sexually transmitted diseases, with inadequate follow-up of prenatal and maternity protocols.

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