scholarly journals Gastrocnemius medialis contractile behavior during running differs between simulated Lunar and Martian gravities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charlotte Richter ◽  
Bjoern Braunstein ◽  
Benjamin Staeudle ◽  
Julia Attias ◽  
Alexander Suess ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Joint Kinematics ◽  
Gravity Level ◽  
Simulation Studies ◽  
Lunar Gravity ◽  
The Moon ◽  
Joint Angles ◽  
Gastrocnemius Medialis ◽  
International Partnership ◽  
Reaction Forces

AbstractThe international partnership of space agencies has agreed to proceed forward to the Moon sustainably. Activities on the Lunar surface (0.16 g) will allow crewmembers to advance the exploration skills needed when expanding human presence to Mars (0.38 g). Whilst data from actual hypogravity activities are limited to the Apollo missions, simulation studies have indicated that ground reaction forces, mechanical work, muscle activation, and joint angles decrease with declining gravity level. However, these alterations in locomotion biomechanics do not necessarily scale to the gravity level, the reduction in gastrocnemius medialis activation even appears to level off around 0.2 g, while muscle activation pattern remains similar. Thus, it is difficult to predict whether gastrocnemius medialis contractile behavior during running on Moon will basically be the same as on Mars. Therefore, this study investigated lower limb joint kinematics and gastrocnemius medialis behavior during running at 1 g, simulated Martian gravity, and simulated Lunar gravity on the vertical treadmill facility. The results indicate that hypogravity-induced alterations in joint kinematics and contractile behavior still persist between simulated running on the Moon and Mars. This contrasts with the concept of a ceiling effect and should be carefully considered when evaluating exercise prescriptions and the transferability of locomotion practiced in Lunar gravity to Martian gravity.

scholarly journals Gastrocnemius Medialis Contractile Behavior During Running Differs Between Simulated Lunar and Martian Gravities

2021 ◽  
Author(s):  
Charlotte Richter ◽  
Bjoern Braunstein ◽  
Benjamin Staeudle ◽  
Julia Attias ◽  
Alexander Suess ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Joint Kinematics ◽  
Ground Reaction Forces ◽  
Gravity Level ◽  
Simulation Studies ◽  
The Moon ◽  
Joint Angles ◽  
Gastrocnemius Medialis ◽  
International Partnership ◽  
Reaction Forces

Abstract The international partnership of space agencies has agreed to proceed forward to the Moon sustainably. Activities on the Lunar surface (0.16g) will allow crewmembers to advance the exploration skills needed when expanding human presence to Mars (0.38g). Whilst data from actual hypogravity activities are limited to the Apollo missions, simulation studies have indicated that ground reaction forces, mechanical work, muscle activation and joint angles decrease with declining gravity level. However, these alterations in locomotion biomechanics do not necessarily scale to gravity level, the reduction in gastrocnemius medialis activation even appears to level off around 0.2g, whilst muscle activation pattern remains similar. Thus, it is difficult to predict whether gastrocnemius medialis contractile behavior during running on Moon will basically be the same as on Mars. Therefore, this study investigated lower limb joint kinematics and gastrocnemius medialis behavior during running at 1g, simulated 0.38g and 0.16g on the vertical treadmill facility. The results reveal that hypogravity-induced alterations in joint kinematics and contractile behavior still persist between simulated running on Moon and Mars. This contrasts the idea of a ceiling effect and should be carefully considered when evaluating exercise prescriptions and the transferability of locomotion practiced in Lunar gravity to Martian gravity.

scholarly journals The Effect of Method of Instruction Given on Muscle Activation and Kinematic During Vertical and Horizontal Based Strength Training

2019 ◽  
Vol 8 (12) ◽  
pp. 683-685
Keyword(s):  
Strength Training ◽  
Teaching And Learning ◽  
Muscle Activation ◽  
Mechanical Effect ◽  
Learning Approach ◽  
Joint Angles ◽  
Technical Aspects ◽  
Method Of Instruction

Lunge and squat exercises are two exercises mainly used in strength training due to its multi-joint, structural and free weights nature and benefits. Main aim of this study is to determine the effect of verbal and video-based mode of instructions on both exercises. Joint angles and muscle activation were measured as an indicator or determinants of the effect of the exercises. Thirty male participants were recruited and involved in two testing occasions. Results of the study indicated no significant differences for both exercises in term of all determinants measured. As a conclusion, mode of instructions may give variety to teaching and learning approach for both exercises, but it produces similar effects. Most important is to ensure in any mode of instructions utilized, the technical aspects given are based on correct biomechanical ques for optimal mechanical effect.

Cardiopulmonary Resuscitation in Hypogravity Simulation

2021 ◽  
Vol 92 (2) ◽  
pp. 106-112
Author(s):  
Sindujen Sriharan ◽  
Gemma Kay ◽  
Jimmy C.Y. Lee ◽  
Ross D. Pollock ◽  
Thais Russomano
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Lunar Gravity ◽  
The Moon ◽  
Chest Compressions ◽  
Resuscitation Guidelines ◽  
Cpr Quality ◽  
Gender Space ◽  
External Chest Compressions ◽  
Mixed Gender ◽  
Interplanetary Travel

BACKGROUND: Limited research exists into extraterrestrial CPR, despite the drive for interplanetary travel. This study investigated whether the terrestrial CPR method can provide quality external chest compressions (ECCs) in line with the 2015 UK resuscitation guidelines during ground-based hypogravity simulation. It also explored whether gender, weight, and fatigue influence CPR quality.METHODS: There were 21 subjects who performed continuous ECCs for 5 min during ground-based hypogravity simulations of Mars (0.38 G) and the Moon (0.16 G), with Earths gravity (1 G) as the control. Subjects were unloaded using a body suspension device (BSD). ECC depth and rate, heart rate (HR), ventilation (VE), oxygen uptake (Vo2), and Borg scores were measured.RESULTS: ECC depth was lower in 0.38 G (42.9 9 mm) and 0.16 G (40.8 9 mm) compared to 1 G and did not meet current resuscitation guidelines. ECC rate was adequate in all gravity conditions. There were no differences in ECC depth and rate when comparing gender or weight. ECC depth trend showed a decrease by min 5 in 0.38 G and by min 2 in 0.16 G. Increases in HR, VE, and Vo2 were observed from CPR min 1 to min 5.DISCUSSION: The terrestrial method of CPR provides a consistent ECC rate but does not provide adequate ECC depths in simulated hypogravities. The results suggest that a mixed-gender space crew of varying bodyweights may not influence ECC quality. Extraterrestrial-specific CPR guidelines are warranted. With a move to increasing ECC rate, permitting lower ECC depths and substituting rescuers after 1 min in lunar gravity and 4 min in Martian gravity is recommended.Sriharan S, Kay G, Lee JCY, Pollock RD, Russomano T. Cardiopulmonary resuscitation in hypogravity simulation. Aerosp Med Hum Perform. 2021; 92(2):106112.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Gastrocnemius Medialis ◽  
Leg Muscles ◽  
Relative Activation ◽  
Muscle Groups ◽  
High Level

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.

Human Factors Review of Space Habitat Feature Requirements

2017 ◽  
Vol 61 (1) ◽  
pp. 62-62
Author(s):  
James Flores ◽  
Farzan Sasangohar
Keyword(s):  
Parabolic Flight ◽  
Vertical Displacement ◽  
Human Motion ◽  
The Moon ◽  
Friction Forces ◽  
Transition Speed ◽  
Human Scale ◽  
Partial Gravity ◽  
Ceiling Height ◽  
Reaction Forces

Sending humans to other planets requires an understanding of the effects of the partial gravity on human motion before attempting to design or build buildings or plan mission tasks. Architecture is the most basic example of human-centered design as everything in a building is to “human” scale. While some modern studies (e.g., Capps, et. al, 1989) reference a study which looked at the humans and forces for the Moon landing (Hewes et. al, 1966), this study was never correlated with the actual lunar data and has many erroneous assumptions. Previous work in Biomechanics was reviewed and the elements of physics required to analyze human motion in partial gravity was analyzed and several basic questions were generated. Included in these studies are NASA studies which look at parabolic flight and apparatus to simulate the effects of partial gravity (NASA/TM-2010-216139, 2010). The key part of physics that drives the changes in human motion is the fact that the momentum of a human or object in motion remains the same while gravity reduces the normal forces on the feet which in turn cause a reduction in the friction reaction forces available for maneuvering or stopping. The study investigates design of several building features for space architecture. These include: Ceiling Height, Door Size, Railing Height, Stairs, Ladders, and Ramps. The first of these the ceiling height relates to the question of does a person “bounce” when they walk in partial gravity. Typical ceilings on Earth range from 2.44 m (8 feet) to 3.05 m (10 feet) Studies of walk to run transition speed for partial gravity were reviewed and they measured the vertical displacement of the hip. This measurement varied by less than 1 cm and correlated to a minimal head height change. Door sizes and railing heights related to the height of 99th percentile humans projected to the year of launch to Mars or the Moon and also included spinal growth caused by 0 g transit. These projections do lead to a taller door opening (25 cm) and raised railing (14.3 cm) as compared to earth. Stairs and ladders both ended up being related to joint angles and human preferences such that they remain the same as on Earth. Chair heights which also relate to counter heights were looked at by reviewing studies of the sit-to-stand motion and comparing the foot and buttocks reaction forces to the friction forces available on Mars and the Moon verses Earth standard. This leads to a recommendation to use Pub height chairs and counters. Flooring and ramps required scaling and also calculating equivalency values to make comparisons. It was determined that the required friction when scaled to Mars would be possible with fairly standard flooring materials. The Lunar case however, would require a combination of high friction flooring and training for nominal movement. To analyze ramps independent calculations were used for friction requirements and then correlated to a study of emergency personnel pushing a trolley with a patient up or down a ramp. Both these methods correlated to an extremely shallow 2.86 degrees (slope 1 in 20) ramp being possible on Mars and ramps not being usable on the Moon. Based on these factors it is recommended that many of features follow standards used on earth and that only the required changes be made such that the habitation resemble Earth structures as much as possible. In addition, Astronaut training should incorporate these factors into their procedures.

Correlation of Surface Electromyography of the Vastus Lateralis Muscle in Dogs at a Walk with Joint Kinematics and Ground Reaction Forces

2009 ◽  
Vol 38 (6) ◽  
pp. 754-761 ◽  
Author(s):  
BARBARA B. BOCKSTAHLER ◽  
ROLAND GESKY ◽  
MARION MUELLER ◽  
JOHANN G. THALHAMMER ◽  
CHRISTIAN PEHAM ◽  
...  
Keyword(s):  
Surface Electromyography ◽  
Vastus Lateralis ◽  
Joint Kinematics ◽  
Vastus Lateralis Muscle ◽  
Ground Reaction Forces ◽  
Lateralis Muscle ◽  
Reaction Forces

scholarly journals Ground Reaction Force Estimation in Prosthetic Legs With Nonlinear Kalman Filtering Methods

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Seyed Fakoorian ◽  
Vahid Azimi ◽  
Mahmoud Moosavi ◽  
Hanz Richter ◽  
Dan Simon
Keyword(s):  
Kalman Filter ◽  
Continuous Time ◽  
Lyapunov Functions ◽  
Unscented Kalman Filter ◽  
Estimation Error ◽  
Reaction Force ◽  
Force Estimation ◽  
Joint Angles ◽  
Estimation Errors ◽  
Reaction Forces

A method to estimate ground reaction forces (GRFs) in a robot/prosthesis system is presented. The system includes a robot that emulates human hip and thigh motion, along with a powered (active) transfemoral prosthetic leg. We design a continuous-time extended Kalman filter (EKF) and a continuous-time unscented Kalman filter (UKF) to estimate not only the states of the robot/prosthesis system but also the GRFs that act on the foot. It is proven using stochastic Lyapunov functions that the estimation error of the EKF is exponentially bounded if the initial estimation errors and the disturbances are sufficiently small. The performance of the estimators in normal walk, fast walk, and slow walk is studied, when we use four sensors (hip displacement, thigh, knee, and ankle angles), three sensors (thigh, knee, and ankle angles), and two sensors (knee and ankle angles). Simulation results show that when using four sensors, the average root-mean-square (RMS) estimation error of the EKF is 0.0020 rad for the joint angles and 11.85 N for the GRFs. The respective numbers for the UKF are 0.0016 rad and 7.98 N, which are 20% and 33% lower than those of the EKF.

Influence of the Musculotendon Dynamics on the Muscle Force-Sharing Problem of the Shoulder—A Fully Inverse Dynamics Approach

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Quental Carlos ◽  
Azevedo Margarida ◽  
Ambrósio Jorge ◽  
Gonçalves S. B. ◽  
Folgado João
Keyword(s):  
Muscle Activation ◽  
Inverse Dynamics ◽  
Glenohumeral Joint ◽  
Inverse Dynamic ◽  
Force Sharing ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Muscle Activations ◽  
Joint Reaction

Abstract Most dynamic simulations are based on inverse dynamics, being the time-dependent physiological nature of the muscle properties rarely considered due to numerical challenges. Since the influence of muscle physiology on the consistency of inverse dynamics simulations remains unclear, the purpose of the present study is to evaluate the computational efficiency and biological validity of four musculotendon models that differ in the simulation of the muscle activation and contraction dynamics. Inverse dynamic analyses are performed using a spatial musculoskeletal model of the upper limb. The muscle force-sharing problem is solved for five repetitions of unloaded and loaded motions of shoulder abduction and shoulder flexion. The performance of the musculotendon models is evaluated by comparing muscle activation predictions with electromyography (EMG) signals, measured synchronously with motion for 11 muscles, and the glenohumeral joint reaction forces estimated numerically with those measured in vivo. The results show similar muscle activations for all muscle models. Overall, high cross-correlations are computed between muscle activations and the EMG signals measured for all movements analyzed, which provides confidence in the results. The glenohumeral joint reaction forces estimated compare well with those measured in vivo, but the influence of the muscle dynamics is found to be negligible. In conclusion, for slow-speed, standard movements of the upper limb, as those studied here, the activation and musculotendon contraction dynamics can be neglected in inverse dynamic analyses without compromising the prediction of muscle and joint reaction forces.

Lunar gravity determinations and their implications

1977 ◽  
Vol 285 (1327) ◽  
pp. 219-226 ◽  
Keyword(s):  
Gravity Data ◽  
Lunar Gravity ◽  
The Moon ◽  
Rigid Surface ◽  
Near Surface ◽  
Homogeneous Sphere ◽  
Mass Distributions ◽  
Isostatic Adjustment ◽  
History Of ◽  
Radiometric Data

The variations in speed of the orbiting Apollo spacecraft as observed from Earth-based radiometric data have provided a direct measure of the local gravitational field. The gravity data were used to infer mass distributions that relate to topography in varying degrees. The mascons exist as mass excesses in topographic lows in all the near-side ringed basins and are best represented as near surface disks with excess loads of 800 kg/cm2. Large 100 km size craters like Langrenus, Theophilus, and Copernicus have mass deficits that are consistent with the craters’ volumes. Both of these results imply a relatively rigid surface layer that allowed little isostatic adjustment over lunar time. However, the Apennine mountains, presumably formed at the time of the Imbrium impact event, reveal only a small gravitational anomaly compared to their topographic size. This suggests that at this era the Moon was more plastic and isostatically compensated. By using the orbital element history of the subsatellites, the first realistic far-side field has been determined. The far-side ringed basins are mass deficits consistent with the lack of maria filling. The 2 km centre-ofgravity offset from the geometric centre implies a thicker far-side crust that possibly prevented far-side maria flooding. The homogeneity parameter (C/MR2) is near that of a homogeneous sphere having possibly a small core with a slight density increase towards its centre.

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