Subject(s)
Fees, Medical , Interprofessional Relations , Physicians , Altruism , Humans , South AfricaSubject(s)
Informed Consent , Malpractice , General Surgery/standards , Guidelines as Topic , Humans , South AfricaSubject(s)
Lumbar Vertebrae/surgery , Sacrum/surgery , Spinal Fusion/adverse effects , Spine/pathology , HumansABSTRACT
A hypothesis is offered which extends the concept of proprioception to use information necessarily obtained during the first part of a complex motion (stepping down) to facilitate the second part. It is suggested that, when the leading foot of a normal person stepping down arrives at its destination, relevant proprioceptive information is used by the following foot in its descent, to render its movement more efficient. Analogy to another effort-minimizing proprioceptive mechanism and a possible mechanical manifestation of the hypothesis are given.
Subject(s)
Locomotion/physiology , Proprioception/physiology , Biomechanical Phenomena , Foot/physiology , Gait/physiology , Humans , Models, Biological , Motion Perception/physiology , Movement/physiology , Walking/physiologyABSTRACT
This study was undertaken to determine the geometric form of the surface on which a fixed point on the head moves as a result of neck motion. Motion of a retroreflective marker on the glabella of six normal subjects was stereoscopically recorded by two video cameras, during a variety of neck motions, performed on command. Near real-time computer analysis in three dimensions of the video images showed the marker moved on a surface that very closely approximated an elliptical paraboloid (with tendency to a hemisphere), after extraneous shoulder motion had been eliminated. Parameters defining the elliptical paraboloids were obtained. Using a reflex microscope, the shape of the articular facets on skull base and superior facets of C1 and C2 of 6 normal subjects were examined. The shapes of all these facets were calculated and also found to be elliptical paraboloids.
Subject(s)
Cervical Vertebrae/physiology , Head/physiology , Image Processing, Computer-Assisted , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Movement/physiology , Videotape RecordingSubject(s)
Bone and Bones , Cauda Equina , Foreign-Body Migration , Intervertebral Disc , Nerve Compression Syndromes/etiology , Sciatica/etiology , Adult , Female , Humans , Male , Middle AgedABSTRACT
Changes in the law related to, and the administration of, compensation under the Motor Vehicle Insurance Act of 1972 are likely in the near future. This Act makes the treating medical practitioner an obligatory assessor of damage incurred by individuals entitled to compensation under this legislation by completion of an MVA 13 form. The value judgment of a treating practitioner and an independent medical assessor in defining injuries and disabilities subject to legal claims are discussed and 5 cases are used to illustrate the disadvantages of the treating medical practitioner as the definitive source of assessment opinion--these are lack of objectivity, perpetuation of errors of omission and lack of specialized knowledge. The very limited value (if any) of the MVA 13 form is emphasized.
