Hungarian Society of Biomechanics: E-Journals / Magyar Biomechanikai Társaság
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Neck posture measurement amongst schoolchildren
Get PDFBackground: There is a paucity in basic data concerning neck posture in childhood. Our aim was to gain preliminary data on the head/neck/shoulder posture, and to document their evolution with growth in schoolchildren.Methods: For measuring posture digital photographs were taken of the children seated in a straight-high-backed chair. The camera (Agfa 5Ti, 5.2 megapixels) was located perpendicularly to each subject’s height, positioned from the left side, the focus was on the tragus with a standard distance of 150 cm. The fi rst photo was taken in the “neutral head posture” and a second photo in “resting” posture). The digital photos were then evaluated by a computer software program (distributed as Marker Angels). The angles analyzed were as follows: the craniovertebral angle (CVA), the head tilt angle (HTA), the shoulder angle (SHA). Subjects were hundred and fortyseven 9-year old, and hundred and fourtythree 16-year old schoolchildren, who were attending public school in different districts of Budapest.Results: In the 16-year old’s group the CVA values have been found reduced signifi cantly (by an average of 8 degrees in neutral position and 6 degrees in resting position) compared to the 9 year olds. The HTA elevated by an average of 1.6 degrees (NS) in neutral position and reduced signifi cantly (by 4.2 degrees) in resting position. The values of the SHA elevated signifi cantly (by an average of 13.33 degrees in neutral position and 13.32 degrees in resting) between the 9–16 year olds, which referred to more protracted shoulder posture.Discussion: The CVA characterizes the neck posture, the less it’s value, the more the forward position. The neck posture is in strong correlation to the head and the shoulder positions. That means forward bent neck position is in correlation to the so called “rounded” shoulder or the shoulder protraction. Although the position of the was found not consequent in neutral position, however was in correlation in resting position.Conclusion: Measuring head/neck/shoulder posture by means of digital photos and evaula ted by computer program proved easy, useful method. We obtained preliminary descriptive data on neck posture in degrees of two age groups of schoolchildren. The comparison of the results pro ved the tendency of progression in “poor posture” during 7 schoolyears, between in the age of 9–16. DOI: 10.17489/biohun/2010/1/2
Sensitivity investigation of three-cylinder model of human knee joint
Get PDFThe operation is unavoidable in a certain part of patients suffering from arthrosis. The contact surfaces of wide-spread applied human knee joint prostheses can be described with simple geometrical elements. The relative motion realized by knee joint and as its results the stability of the whole body is harmonic ensured by complicated condyle surfaces. For this reason the implanted prostheses comply with requirements limited and it causes additional load on the diseased bony tissue. According to observations at the fastening of the prostheses the bony tissues become inflamed which after some years need new operation.At present it is a general aim in biomechanics to create a better mechanical model of human knee joint which can approach the natural motion and on its basis to make new prostheses. The motion of the human knee joint have been studying by many biomechanical research groups for decades. The problem is very complex and specifi c from technical point of view. The cause of complexity is partly the elaborateness of elements, partly the typical rheological properties of the components (bones, cartilages and other soft tissues).Authors as members of the Szent István University Biomechanical Research Group in order to describe the motion of knee joint at fi rst joined coordinate-systems on the basis of anatomical landmarks to the femur and tibia moreover joined a three-cylindrical mechanism as mechanical model to the axes of coordinate-systems.The aim of the investigation is to determine the six independent kinematical parameters of tibia compared to the fixed femur during fl exion and extension. The experimental examinations were carried out on cadaver knees in cooperation with doctors of Szent János Hospital. The positioning was tracked by optical positioning appliance. Needed parameters can be obtained from the recorded data determined by the kinematical model.Considering the irregular shapes of femur and tibia the anatomical coordinate systems can be joined with more or less position mistake. The aim of this paper is the determination of the effects of position mistakes on kinematical parameters. DOI: 10.17489/biohun/2010/1/0
Development of bone tissue-analogous implant of functional capacity and of integration range, microscopic incorporation examination of animal experiment implantation series
Get PDFDOI: 10.17489/biohun/2010/1/0
A non-invasive method for the examination of muscle geometry to the exploration of the context of the muscle activities and muscle length changes
Get PDFDOI: 10.17489/biohun/2010/1/1
The effects of infrared laser therapy and weightbath traction hydrotherapy in disorders of the lumbar spine: a controlled pilot study with follow-up
Get PDFIntroduction: The therapeutic modalities available for the conservative management of chronic lumbar pain included infrared laser therapy and underwater traction, which usefulness is not universally acknowledged. This study was intended to ascertain any benefi cial impact of infrared laser therapy and weightbath treatment on the clinical aprameters and quality of life of patients with lumbar discopathy.Material and methods: The study population comprised 54 randomised subjects. I. group of 18 patents received only infrared laser therapy to lumbar region and painful Valley points. II. Group of 18 subjects each received underwater traction therapy of lumbar spine with add-on McKenzie exercise and iontophoresis. The remaining III. Group treated with exercise and iontophoresis, served as control. VAS, Oswestry index, SF36 scores, range of motion, neurological fi ndings and thermography were monitored to appraise therapeutic affi cacy in lumbar discopathy. A CT or MRI scan was done at baseline and after 3 months follow-up.Result: infrared laser therapy and underwater traction for discopathy achieved signifi cant improvement of all study parameters, which was evident 3 months later. Among the controls, signifi - cant improvement of only a single parameter was seen in patients with lumbar disco pathy.Conclusions: infrared laser therapy and underwater traction treatment effectively mitigate pain, muscle spasms, enhance joint fl exibility, and improve the quality of life of patients with lumbar discopathy. DOI: 10.17489/biohun/2010/1/2
Comparison of biomechanical changes in respect of pain scores after lumbar fusion
Get PDFLow back pain is one of the leading causes of disability, some patients don’t respond to conservative therapy, and must undergo surgery. The aim of our study was to investigate the results of lumbar fusion operations, especially considering the changes in the sagittal range of motion (ROM) in the adjacent segments, thoracic, lumbar region and pain. 13 patients were involved, who had lumbar LIV/V rigid fusion (TLIF) operation, and still had low back pain symptoms. For the biomechanical measurement we used the Spinal Mouse, a computer associated device, based on electromagnetic impulses. For estimating the pain we used the 3D pain questionnaire (West-Haven-Yale Multidimensonal Pain Inventory [WHYMPI]).In the outline analysis we found that the decrease in pain and improvement of symptoms after a lumbar fusion is defi nitely the result of increased thoracic segment hypermobility, decreased lumbar segment hypomobility, decreased proximal adjacent segment hypomobility and, increase of the distal adjacent segment hypomobility. The sagittal range of motion (ROM) of the whole spine, as the hypomobility is corrected towards the normal ROM resulted in decrease of pain. In conclusion we can notice when using semirigid systems for bridging adjacent segments, it is important to secure the hypermobility of the thoracic spine, and the mobility of the proximal segment. DOI: 10.17489/biohun/2010/1/0
Kinematic model construction of lower limb based on linkage model
Get PDFThe human skeleton from mechanical point of view is a multi degree of freedom system supportingstructure. Depending upon the fact whether the muscle groups are tightened, the supportingstructure can be either determinate structure or statically indeterminate structure. Thetightened muscles turn into the part of the supporting structure, the slack muscles make it possiblethat the structure operates as a mechanism. In this paper the simplified kinematics modelof the lower limb and its analysis are presented. DOI: 10.17489/biohun/2009/2/0