Biomechanical Analysis of Human Stair Climbing (Ascending and Descending)

Because stair climbing is a common activity of daily living, the ability to do it efficiently is important to an individual's quality of life. More demanding than level walking, stair ambulation is performed with ease by healthy individuals; however, it is more difficult to perform for those with decrements in motor function, balance problems, or reduced lower-limb function. The difficulty with stair climbing is attributable to increased muscular demands, which are reflected in larger forces, angles, powers, moments, and ranges of motion, and these increased demands occur consistently at the knee joint. Kinematic system is used in stair climbing to record the position and orientation of the body segments, the angles of the joints and the corresponding linear and angular velocities and acceleration. The purpose of the study is to show an ideal kinematics appearance of human gait cycle for stair climbing in order to get measurement values that can be depended on in the hospitals of rehabilitation, the centers of physical therapy and the clinical of medical sports as a reference data for kinematic joint parameter. In this study, 5 subjects were selected from the society, then a video recording was made for them by using a single digital video camera recorder fitted on a stand of three legs in a sagittal plane while subjects climbing a stair one by one for different stair heights. Motion analysis was used to study the knee and hip joint kinematics. As a result, it was observed that the range of motion at the hip joint is between (10°-70°) at ascending and the range is between (20°-50°) at descending. The range of motion at the knee joint is between (20°-90°) at ascending and the range is between (10°-100°) at descending. The range of motion at the ankle joint is between (-25°-20°) at ascending and the range is between (-25°-15°) at descending. Also it was found that the angular velocity at the hip joint is between (-10-10) deg/s for ascending and (-15-25) deg/s for descending. The angular velocity at the knee joint is between (-40-30) deg/s for ascending and (-30-50) deg/s for descending. The angular velocity at the ankle joint is between (-30-20) deg/s for ascending and (-15-15) deg/s for descending. In this study, biomechanical characteristics of lower limb joint upon various stair height were presented and these data can be applied to biomedical research field that include wearable walking assistant robot

An Investigation Behavior Into Dental Biomechanical Analysis

The aim of the study is to evaluate the Von Mises stress distribution of different human teeth model. Three-dimensional model of the maxillary central incisor, mandibular first molar and mandibular central incisor were constructed using Auto CAD (Auto CAD 2007) software and then imported to ANSYS software (ANSYS V.10) to get finite element model of each teeth. A loading simulating the 200N force was applied vertically and with different inclination to the crowns. Then same loading was applied vertically but the load was distributed along the incisal area for the incisors and at occlusal margin for the molar. Finally the crown was considered as porcelain material and the vertical load was distributed along each tooth and the Von Mises stresses were calculated. The results showed that the increase in the loading angle from 0°, 26° to 45° resulted in an increase in tooth Von Mises stress which means increase the probability of tooth failure. When the load distributed along wide region the ability of model to fail for the same loading will be decreased. Also when the crown consider as porcelain material there will be increasing Von Mises stress compare with the enamel crown for the same load region and load valu

The Effect Of Increasing Dialysate Flow Rate In Hemodialysis

Hemodialysis is a technique of removing, or clearing , solutes from the blood and removal of extra fluid from the body, by using dialyzing machine and a dialyzer which is also known as (artificial kidney). The principle of hemodialysis is, primarily, the diffusion of solutes across a semipermeable membrane and ultrafiltration for removal of extra fluid. The purpose of this study is to demonstrate the effect of increasing nominal dialysate flow rate from 500 ml/min to 800 ml/min on the amount of the small solutes (urea) removed from the blood and examine its effect on the amount of dialysis delivered. In this study the in vivo effects of increase in dialysate flow rate on the delivered dose of dialysis studied on 28 maintenance hemodialysis patients. Hemodialysis was performed at dialysate flow rates 500 and 800 ml/min. The patients treated two times per week for 3 hours. The results show increase in urea clearance and dialysis adequacy, and a significant increase in the urea difference between pre- and post-blood urea concentration by increasing dialysate flow rate from 500 to 800 ml/min. It can be concluded that hemodialysis with dialysate flow rate 800 ml/min should be considered in selected patients not achieving adequacy despite extended treatment times and optimized blood flow rate. And increasing nominal dialysate flow rate from 500 ml/min to 800 ml/min alters the mass transfer characteristics of hollow fiber hemodialyzer and results in a larger increase in urea clearance

Effects of Backpack Loads on Kids Posture

Kids carrying heavy loads as a part of everyday activity may be related to bend their trunks forward to maintain body posture and balance while walking. This study was to determine a correlation between the weight of a child's backpack, their body weight, and certain features of their body posture. The study group consisted of 6 children, in age of primary school. The anthropometry (age, length, weight) were taken for each volunteers. A school backpack was specially built for the present study. Walking gait was filmed in three cases: (zero kg, 3 kg and 6 kg) backpack. Posture was analyzed by using (Kenova and MATLAB) computer programs. The results show that the forward inclination of the trunk increases when the load and the walking distance are increased, this forward inclination segment may impose greater stress over the vertebral column (ligaments and intervertebral disks) and increase the risk of back problems. Spine and back health may be adversely affected by load carriage and it may be important to use spinal curvature as a measure of posture for load carriage. This study shows that the backpack load cause a lumbar asymmetry by 10 to 20 degree according to the load which has a significant amount of back pain in kids

A BiomechanicalModel Study of the Rat as a Medial Collateral Ligaments of the Knee

Ligament primarily stabilizes the diarthrodial joints and function to provide stability and support during the motion of diarthrodial joints. These functions are assisted by the congruent geometry of the articulating joint surfaces and musculotendinous forces. Ligament exhibits viscoelastic, or time-dependent behavior, like many tissues in the body. From the medical point of view an understanding of the biomechanics of ligaments are crucial for the understanding of injury mechanisms and to evaluate existing surgical repair techniques. The mode of failure in ligaments depends strongly on the rate of loading. Thus, ligament viscoelasticity is an important determinant of tissue response to loading, and viscous dissipation by the tissue modulates the potential for injury. Many mathematical models have been developed to describe the complexity of these behaviors that could include the microphysical interactions of various constituents but none of them seems to represents the overall properties of these structures. Models can be an important tool in understanding tissue structure-function relationships and elucidating the effects of injury, healing, and treatment. The main objective of this work is to study from the biomechanical point of view, the behaviour of an example of the medial collateral ligament in response to stress and strain effects to evaluate the biological behaviour of the ligament. The strain effect as example of the modified superposition method and analyze the results and the model that can express the medial collateral ligament behaviou

Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic

Articular Cartilage Surface Topography and Roughness in Frozen Tissue Samples Using Optical Coherence Microscopy

This paper describes a method to visualize the topography of the surface of cartilage. Optical Coherence Microscopy (OCM) technique has been used to get two dimensional images of frozen tissue samples of bovine articular cartilage. Optical Coherence Microscopy (OCM) is a combination of optical coherence tomography and confocal microscopy. Coherence gate from OCT and confocal gate from confocal microscopy can achieve higher resolution and deeper penetration depth. The precise three-dimensional topography of the cartilage surfaces has been obtained. The full-image roughness, for frozen samples has been obtained

Kinematic analysis of human gait cycle

Kinematic system is used in gait analysis to record the position and orientation of the body segments, the angles of the joints and the corresponding linear and angular velocities and acceleration. Gait analysis is used for two very different purposes to aid directly in the treatment of individual patients and to improve our understanding of gait through research. The purpose of the study is to show an ideal kinematics appearance of human gait cycle for walking in order to get measurement values that can be depended on in the hospitals of rehabilitation, the centers of physical therapy and the clinical of medical sports as a reference data for kinematic joint parameter. In this study, 20 subjects and one abnormal subject (undergoes foot flat) were selected from the society; the 20 subjects were not to have any pathology that would affect gait and had to be unfamiliar with treadmill walking, then a video recording was made for them by using a single digital video camera recorder fitted on a stand of three legs in a sagittal plane while subjects walked on a motorized treadmill one by one, the treadmill is often used in rehabilitation programs because it allows standard and controlled conditions and it needs small space. Then by special motion analysis software (Dartfish) was used to study the knee and hip joint kinematics and the spatial –temporal gait parameters (step length, stride length, stride duration, cadence) from the video recording. Results obtained from the Dartfish program are important in understanding that the knee and hip angles differ in each gait cycle, similarly to spatial- temporal parameters, the spatial- temporal parameters differ in each gait cycle analyzed for subjects