Rescuer’s Position and Energy Consumption, Spinal Kinetics, and Effectiveness of Simulated Cardiac Compression

2008 ◽  
Vol 17 (5) ◽  
pp. 417-425 ◽  
Author(s):  
Alice Y.M. Jones ◽  
Raymond Y.W. Lee
Keyword(s):  
Oxygen Consumption ◽  
Chest Compression ◽  
Force Plate ◽  
Lower Limbs ◽  
Emergency Medical Technicians ◽  
Chest Compressions ◽  
Cardiac Compression ◽  
Reaction Forces ◽  
Tracking Device ◽  
Kinetics Of

Background Cardiopulmonary resuscitation is often performed in compromised conditions and for long periods. Objective To compare energy expenditure, compression effectiveness, and kinetics of the spine during simulated chest compression with the rescuer in different positions. Methods A 3-group design with 36 nurses (26 females) and 20 male emergency medical technicians was used. Participants performed chest compressions on a mannequin while kneeling on the floor, standing, or kneeling on the bed at the edge of the mattress (bed mount). Oxygen consumption and effectiveness of chest compression were recorded. Muscle moment and power at the lumbosacral joint were determined by recording motions of the lower limbs and pelvis with an electromagnetic tracking device and measuring ground reaction forces with a force plate. Results A total of 80% of chest compressions delivered by male rescuers (vs 40% delivered by females) were effective, irrespective of position. Male rescuers consumed less oxygen when delivering chest compressions while standing than while kneeling (P = .03), but effective compression ratio also was lower. In female rescuers, effective compressions correlated positively with oxygen consumption in the standing (r = 0.42, P = .04) and bed-mount (r = 0.53, P = .008) positions. Administering chest compressions while standing involved a larger moment magnitude and required more power than doing so while kneeling. Conclusion Administering chest compressions while standing demands more power but consumes less oxygen than doing so while kneeling, perhaps because fewer cardiac compressions delivered while standing are effective.

Abstract 482: Differences in Ground Reaction Forces and Chest Compression Release Velocity in Professional and Lay Rescuers With and Without the Use of Real-Time CPR Feedback

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Lyra Clark ◽  
Ben Senderling ◽  
Jeff R Gould ◽  
Chris Kaufman ◽  
Nick Stergiou
Keyword(s):  
Real Time ◽  
Chest Compression ◽  
Reaction Force ◽  
Force Plate ◽  
Compression Cycle ◽  
Reaction Forces ◽  
Force Range ◽  
Favorable Neurological Outcome ◽  
Compression Characteristics ◽  
Pearson Correlations

Purpose: Chest compression release velocity (CCRV) has been associated with survival and favorable neurological outcome after cardiac resuscitation. Both complete chest release and high CCRV contribute to improved venous return during CPR. Differences in compression forces delivered by professional and lay rescuers are reported, which may contribute to differences in CCRV. The aim of this pilot study was to investigate differences in ground reaction force (GRF) and CCRV between professional and lay rescuers during CPR performed on a manikin with and without real-time feedback. Methods: Professional (n = 5) and lay rescuers (n = 11) performed two minutes of continuous compressions on a manikin positioned over a force plate for two trials. CPR feedback provided by a defibrillator was disabled in the first trial and enabled in the second. CPR pads containing an accelerometer were used to calculate individual compression characteristics. Relative maximum and minimum GRFs were calculated for each compression cycle and averaged over each trial. Paired and independent sample t tests and Pearson correlations were conducted in STATA 15.1. Results: CCRV was higher in professionals vs. lay rescuers with feedback disabled and enabled ( p <0.05). Professionals had greater maximal and lower minimum forces than lay rescuers without feedback ( p <0.05), though there were no differences between groups with feedback enabled (Table 1). CCRV was associated with minimum force (r = -0.63, p <0.01) and force range (r = 0.78, p <0.01) in all rescuers. Analysis of GRFs by CCRV for all rescuers indicated lower force minimum (9.71 + 3.16 N, p <0.05) with CCRV >400 mm/s in comparison to CCRV 300-400 mm/s (39.73 + 8.91 N) and CCRV 200-300 mm/s (63.82 + 16.98 N). Conclusions: CPR feedback attenuated differences in GRF between professional and lay rescuers. CCRV was greater in professionals and was associated with measures of GRF, and thus may serve as an indicator of both velocity and amount of chest release.

scholarly journals Effect of Football Shoe Collar Type on Ankle Biomechanics and Dynamic Stability during Anterior and Lateral Single-Leg Jump Landings

2020 ◽  
Vol 10 (10) ◽  
pp. 3362
Author(s):  
Yunqi Tang ◽  
Zhikang Wang ◽  
Yifan Zhang ◽  
Shuqi Zhang ◽  
Shutao Wei ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Ankle Joint ◽  
Force Plate ◽  
Joint Stiffness ◽  
Lower Limbs ◽  
Jump Landing ◽  
Ankle Inversion ◽  
Reaction Forces ◽  
Ankle Biomechanics ◽  
Jump Landings

In this study, we investigated the effects of football shoes with different collar heights on ankle biomechanics and dynamic postural stability. Fifteen healthy college football players performed anterior and lateral single-leg jump landings when wearing high collar, elastic collar, or low collar football shoes. The kinematics of lower limbs and ground reaction forces were collected by simultaneously using a stereo-photogrammetric system with markers (Vicon) and a force plate (Kistler). During the anterior single-leg jump landing, a high collar shoe resulted in a significantly smaller ankle dorsiflexion range of motion (ROM), compared to both elastic (p = 0.031, dz = 0.511) and low collar (p = 0.043, dz = 0.446) types, while also presenting lower total ankle sagittal ROM, compared to the low collar type (p = 0.023, dz = 0.756). Ankle joint stiffness was significantly greater for the high collar, compared to the elastic collar (p = 0.003, dz = 0.629) and low collar (p = 0.030, dz = 1.040). Medial-lateral stability was significantly improved with the high collar, compared to the low collar (p = 0.001, dz = 1.232). During the lateral single-leg jump landing, ankle inversion ROM (p = 0.028, dz = 0.615) and total ankle frontal ROM (p = 0.019, dz = 0.873) were significantly smaller for the high collar, compared to the elastic collar. The high collar also resulted in a significantly smaller total ankle sagittal ROM, compared to the low collar (p = 0.001, dz = 0.634). Therefore, the high collar shoe should be effective in decreasing the amount of ROM and increasing the dynamic stability, leading to high ankle joint stiffness due to differences in design and material characteristics of the collar types.

scholarly journals Effects of Running on Sand vs. Stable Ground on Kinetics and Muscle Activities in Individuals With Over-Pronated Feet

2022 ◽  
Vol 12 ◽  
Author(s):  
AmirAli Jafarnezhadgero ◽  
Nasrin Amirzadeh ◽  
Amir Fatollahi ◽  
Marefat Siahkouhian ◽  
Anderson S. Oliveira ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Force Plate ◽  
Rectus Femoris ◽  
Lower Limbs ◽  
Emg Activity ◽  
Ground Reaction Forces ◽  
Compensatory Mechanism ◽  
Running Speed ◽  
Loading Rates ◽  
Reaction Forces

Background: In terms of physiological and biomechanical characteristics, over-pronation of the feet has been associated with distinct muscle recruitment patterns and ground reaction forces during running.Objective: The aim of this study was to evaluate the effects of running on sand vs. stable ground on ground-reaction-forces (GRFs) and electromyographic (EMG) activity of lower limb muscles in individuals with over-pronated feet (OPF) compared with healthy controls.Methods: Thirty-three OPF individuals and 33 controls ran at preferred speed and in randomized-order over level-ground and sand. A force-plate was embedded in an 18-m runway to collect GRFs. Muscle activities were recorded using an EMG-system. Data were adjusted for surface-related differences in running speed.Results: Running on sand resulted in lower speed compared with stable ground running (p &lt; 0.001; d = 0.83). Results demonstrated that running on sand produced higher tibialis anterior activity (p = 0.024; d = 0.28). Also, findings indicated larger loading rates (p = 0.004; d = 0.72) and greater vastus medialis (p &lt; 0.001; d = 0.89) and rectus femoris (p = 0.001; d = 0.61) activities in OPF individuals. Controls but not OPF showed significantly lower gluteus-medius activity (p = 0.022; d = 0.63) when running on sand.Conclusion: Running on sand resulted in lower running speed and higher tibialis anterior activity during the loading phase. This may indicate alterations in neuromuscular demands in the distal part of the lower limbs when running on sand. In OPF individuals, higher loading rates together with greater quadriceps activity may constitute a proximal compensatory mechanism for distal surface instability.

scholarly journals The role of the contralateral limb in below-knee amputee gait

1990 ◽  
Vol 14 (1) ◽  
pp. 33-42 ◽  
Author(s):  
G. R. B. Hurley ◽  
R. McKenney ◽  
M. Robinson ◽  
M. Zadravec ◽  
M. R. Pierrynowski
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
Force Plate ◽  
Lower Limbs ◽  
Contralateral Limb ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Joint Reaction ◽  
Amputee Gait

Very little quantitative biomechanical research has been carried out evaluating issues relevant to prosthetic management. The literature available suggests that amputees may demonstrate an asymmetrical gait pattern. Furthermore, studies suggest that the forces occurring during amputee gait may be unequally distributed between the contralateral and prosthetic lower limbs/This study investigates the role of the contralateral limb in amputee gait by determining lower limb joint reaction forces and symmetry of motion in an amputee and non-amputee population. Seven adult below-knee amputees and four non-amputees participated in the study. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force data using a Kistler force plate. The degree of lower limb symmetry was determined using bilateral angle-angle diagrams and a chain encoding technique. Ankle, knee and hip joint reaction forces were estimated in order to evaluate the forces acting across the joints of the amputee's contralateral limb. The amputees demonstrated a lesser degree of lower limb symmetry than the non-amputees. This asymmetrical movement was attributed to the inherent variability of the actions of the prosthetic lower limb. The forces acting across the joints of the contralateral limb were not significantly higher than that of the non-amputee. This suggests that, providing the adult amputee has a good prosthetic fit, there will not be increased forces across the joints of the contralateral limb and consequently no predisposition for the long-term wearer to develop premature degenerative arthritis.

Does Foot Anthropometry Predict Metabolic Cost During Running?

2017 ◽  
Vol 33 (5) ◽  
pp. 317-322 ◽  
Author(s):  
Herman van Werkhoven ◽  
Stephen J. Piazza
Keyword(s):  
Oxygen Consumption ◽  
Achilles Tendon ◽  
Body Height ◽  
Force Plate ◽  
Metabolic Cost ◽  
Running Economy ◽  
Metabolic Energy ◽  
Flexor Muscle ◽  
Reaction Forces ◽  
Tendon Force

Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h−1 on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = −.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.

Kinetics of Badminton Lunges in Four Directions

2014 ◽  
Vol 30 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Youlian Hong ◽  
Shao Jun Wang ◽  
Wing Kai Lam ◽  
Jason Tak-Man Cheung
Keyword(s):  
Impact Force ◽  
Force Plate ◽  
Loading Rates ◽  
Plantar Pressures ◽  
Reaction Forces ◽  
University Level ◽  
The Right ◽  
Kinetics Of ◽  
Vertical Impact ◽  
Anterior Posterior

The lunge is the most fundamental skill in badminton competitions. Fifteen university-level male badminton players performed lunge maneuvers in four directions, namely, right-forward, left-forward, right-backward, and left-backward, while wearing two different brands of badminton shoes. The test compared the kinetics of badminton shoes in performing typical lunge maneuvers. A force plate and an insole measurement system measured the ground reaction forces and plantar pressures. These measurements were compared across all lunge maneuvers. The left-forward lunge generated significantly higher first vertical impact force (2.34 ± 0.52 BW) than that of the right-backward (2.06 ± 0.60 BW) and left-backward lunges (1.78 ± 0.44 BW); higher second vertical impact force (2.44 ± 0.51 BW) than that of the left-backward lunge (2.07 ± 0.38 BW); and higher maximum anterior-posterior shear force (1.48 ± 0.36 BW) than that of the left-backward lunge (1.18 ± 0.38 BW). Compared with other lunge directions, the left-forward lunge showed higher mean maximum vertical impact anterior-posterior shear forces and their respective maximum loading rates, and the plantar pressure at the total foot and heel regions. Therefore, the left-forward lunge is a critical maneuver for badminton biomechanics and related footwear research because of the high loading magnitude generated during heel impact.

NORMAL GAIT OF CHILDREN

2003 ◽  
Vol 15 (04) ◽  
pp. 160-163
Author(s):  
PEI-HSI CHOU ◽  
YOU-LI CHOU ◽  
FONG-CHING SU ◽  
WEI-KENG HUANG ◽  
TING-SHENG LIN
Keyword(s):  
Rapid Development ◽  
Body Height ◽  
Force Plate ◽  
Lower Limbs ◽  
Compensatory Mechanism ◽  
Gait Stability ◽  
Gait Parameters ◽  
Basic Studies ◽  
In The Beginning ◽  
Kinetics Of

The rapid development of gait analysis and its increasing application to pathological gait in children has created an urgent need for normative data. However, research on maturation of gait in children is just in the beginning stage in Taiwan. In order to care for the welfare of children, more data and knowledge in the field are mandatory. The first goal of this study is to offer some background data and basic studies to any other researchers who are interested in this topic. The second goal was to investigate the corresponding factors to gait parameters, such as body weight, height, angular deformities (genu varum and valgum) and torsional deformities (toe in and out). In this study, twenty-three children (five years old in average) were included and motion analysis and force plate system were applied to investigate the kinematics and kinetics of lower limbs. The results showed that body height and weight are both corresponding factors to gait development. Gait analyses revealed that there were no differences between boys and girls. Children with genu valgum attend to more gait stability using compensatory mechanism.

Prolonged Kinetics of Recovery of Oxygen Consumption After Maximal Graded Exercise in Patients With Chronic Heart Failure

Circulation ◽  
1995 ◽  
Vol 91 (12) ◽  
pp. 2924-2932 ◽  
Author(s):  
Alain Cohen-Solal ◽  
Thierry Laperche ◽  
Daniel Morvan ◽  
Michel Geneves ◽  
Bernard Caviezel ◽  
...  
Keyword(s):  
Heart Failure ◽  
Oxygen Consumption ◽  
Chronic Heart Failure ◽  
Graded Exercise ◽  
Kinetics Of

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Bilateral Changes in Ground Reaction Forces in Patients with Unilateral Anterior Cruciate Ligament Deficiency During Stair Locomotion

2011 ◽  
Vol 27 (3) ◽  
pp. 437-445 ◽  
Author(s):  
H.-C. Lin ◽  
H.-C. Hsu ◽  
T.-W. Lu
Keyword(s):  
Cruciate Ligament ◽  
Ground Level ◽  
Rehabilitation Program ◽  
Lower Limbs ◽  
Control Group ◽  
Ground Reaction Forces ◽  
Acl Deficiency ◽  
Stair Ascent ◽  
Reaction Forces ◽  
Stair Locomotion

ABSTRACTStair locomotion is an important but challenging functional activity for people with lower limb pathology. This study aimed to investigate the bilateral changes in force-bearing on lower limbs during stair locomotion in patients with unilateral ACL deficiency. The ground reaction forces (GRF) were collected from three force platforms: One at ground level in front of a 5-step stair and two on the first two steps respectively. Parameters in vertical and anterior-posterior GRF were extracted and compared between the ACL-deficient (ACLD) and control groups. The ACLD group showed significantly slower stepping cadences in both stair ascent and stepping down to the ground (p < 0.05). The vertical GRF in the ACLD group demonstrated smaller peak forces but larger minimum forces between the two peaks than those in the control group during both stair ascent and descent. Significantly reduced anterior propulsive forces and push-off rates in the late stance were also found in both limbs of the ACLD group (p < 0.05). The slower cadences and reduced force-bearing on the affected limb suggested a protective strategy was adopted. However, the anterior loading parameters in the early stance on the unaffected limb demonstrated different adaptations with significantly larger magnitudes during stair ascent but reduced magnitudes during stair descent (p < 0.05). Similar results were also found in the weight- transferring strategies between legs in consecutive steps with a significantly larger percentage of lift-up forces but a smaller percentage of impact forces on the leading unaffected limb. The results of this study indicated a cautious force-bearing strategy and bilateral adaptation were apparent in the patients with unilateral ACL deficiency. This information may provide a safety guideline for the patients and be helpful for a better use of the stair tasks as part of a rehabilitation program.

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