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Method of static load evaluation of the wrist joint
Abstracts-InternationalSocietyof BiomechanicsXIV Congress1993
759
VALIDATION OF THE MODELISATION OF THE TRICEPS BRACHII LEVER ARM M. Gerbeaux,E. Turpin, G. Lensel-Corbeil and E. Pertuzon” UFR STAP!$ Universitt Lille II, * UniversitCLille I, FRANCE. A previously establishedmodel permits to calculatethe length, the force and the velocity of shortening at the long portion of the triceps brachii (TB). One way to valide this model was to apply it to the measureof the length of the ‘IB. The measurementswere made on three adult corpses.Each preparationwas fixed on a table and the anglesof the joint were explored from 0.5 rad to 2.2 rad in incrementsof 0.26 rad. At each angular position, the displacementof a marker is noted in relation to the initial position (AL measured= ALm). The length of the TB (L, m) was calculatedas a function of 8, from the previously establishedmodel : L(m) = 1.035d + d (0.0993 8 + 0.01860 e2- 0.0175 e3 + 0.0037 & ) ; d = length of the ulna (m). The variations in length were calculated (AL calculated = AI-c.) in the same angular range as for the measurementof ALm. It appearsthat ALm and ALc are of the sameorderjust until 1.4 rad ; beyond 1.4 rad, the ALc are always superior at ALm. The proposedmodel is thus valid between0.5 rad and 1.4 rad but the calculation takes in accountthe modelisation of the lever arm which has a tendencyto overestimateAI& especially at the elevated angles.It is also possible that the forces of friction affect the measurement.It will therefore be necessaryto make the model more specific and to examine its validity at superiorangles.
NORMATIVE DATA OF DISTANCE-TEMPORAL PARAMETERS OF GAIT C. Giacomozzi, V. Macellari and Ft. Saggin? Biomedical Engineering Laboratory, lstituto Superiore di Sanita’, Rome, Italy Dipartimento di Medicina dello Sport, University G. D’Annunzio, Chieti, Italy Distance-temporal parameters of gait characterise the disorders of the locomotor system and provide basic information for its functional assessment. In this process the reference to basic data from normal populations is often mandatory. A platform developed at the authors’ laboratory is particularly adequate to establish normative data, thanks to the large size of its sensitive surface (48 x 256 cm), which allows the simultaneous acquisition of at least three complete steps. Because of the remarkable variability of gait -even among healthy subjects- it is mandatory to average data over an adequate number of steps. A protocol has been applied to healthy subjects, from children (3 years) to elderly people (70 years), in order to acquire at least eighteen steps at the subject’s usual speed . Geometric parameters (footprint length, footprint width, support area, step, toe out angle, stride breadth) and temporal parameters (stance phase, swing phase, double support phase) have been measured and normalised with respect to height, leg length and speed of progression of each subject. Statistical analysis of data has been performed. Normative data have been obtained by averaging the characteristic parameters of 20 subjects, per sex and per age group. A preliminary analysis of the results shows a slight difference between the two feet, most likely due to the fact that most people are right-handed. l
METHOD OF STATIC LOAD EVALUATION OF THE WRIST JOINT K. Gielo-Perczak Departmentof PhysicalEducation and Recreation, Victoria University of Technology, Melbourne, VIC 3000, Australia A new method is consideredto model the wrist joint structure. The cooperationof the musclesand ligaments servicingthe wrist joint is describedby meansof a statically indeterminatemodel of a variable structure that includesthe influence of the loosejoint as well as the geometry of the joint surfaces.The important considerationsfor the construction of the author’smodel of the wrist joint are as follows: 1) theoretical researchhas been conductedduring wrist deviation, 2) the joint in the deviation plane has been assumedto have two degreesof freedom, 3) the cooperationbetweenthe flexor carpi ulnaris and the flexor carpi radialis muscleshas been assumed,4) cooperation of the collate&e carpi ulnare and collateralecarpi radiale ligamentshas been taken into consideration,5) the analysishas been carried out during radial - ulnar deviation. The analysisof the forces in muscles,ligamentsand the contact forces betweenthe proximal carpal bones and the acetabulumof the ulna and radius, for the two types of wrist joints shows that stressvalues are influencedby the geometry of the joint. An essentialproperty of the author’sproposedmodel of the wrist joint is the possibility of evaluatingthe influence of the geometric parameters;such as defining the cooperatingjoint surfaces,loosenessof the joint, the cross sectionsand the lengthsof musclesand ligaments,the external forces on the hand and the hand position relative to the forearm. The geometry of the joint surfacewas found to be one of the main factors that determinehuman physical strength.
759
VALIDATION OF THE MODELISATION OF THE TRICEPS BRACHII LEVER ARM M. Gerbeaux,E. Turpin, G. Lensel-Corbeil and E. Pertuzon” UFR STAP!$ Universitt Lille II, * UniversitCLille I, FRANCE. A previously establishedmodel permits to calculatethe length, the force and the velocity of shortening at the long portion of the triceps brachii (TB). One way to valide this model was to apply it to the measureof the length of the ‘IB. The measurementswere made on three adult corpses.Each preparationwas fixed on a table and the anglesof the joint were explored from 0.5 rad to 2.2 rad in incrementsof 0.26 rad. At each angular position, the displacementof a marker is noted in relation to the initial position (AL measured= ALm). The length of the TB (L, m) was calculatedas a function of 8, from the previously establishedmodel : L(m) = 1.035d + d (0.0993 8 + 0.01860 e2- 0.0175 e3 + 0.0037 & ) ; d = length of the ulna (m). The variations in length were calculated (AL calculated = AI-c.) in the same angular range as for the measurementof ALm. It appearsthat ALm and ALc are of the sameorderjust until 1.4 rad ; beyond 1.4 rad, the ALc are always superior at ALm. The proposedmodel is thus valid between0.5 rad and 1.4 rad but the calculation takes in accountthe modelisation of the lever arm which has a tendencyto overestimateAI& especially at the elevated angles.It is also possible that the forces of friction affect the measurement.It will therefore be necessaryto make the model more specific and to examine its validity at superiorangles.
NORMATIVE DATA OF DISTANCE-TEMPORAL PARAMETERS OF GAIT C. Giacomozzi, V. Macellari and Ft. Saggin? Biomedical Engineering Laboratory, lstituto Superiore di Sanita’, Rome, Italy Dipartimento di Medicina dello Sport, University G. D’Annunzio, Chieti, Italy Distance-temporal parameters of gait characterise the disorders of the locomotor system and provide basic information for its functional assessment. In this process the reference to basic data from normal populations is often mandatory. A platform developed at the authors’ laboratory is particularly adequate to establish normative data, thanks to the large size of its sensitive surface (48 x 256 cm), which allows the simultaneous acquisition of at least three complete steps. Because of the remarkable variability of gait -even among healthy subjects- it is mandatory to average data over an adequate number of steps. A protocol has been applied to healthy subjects, from children (3 years) to elderly people (70 years), in order to acquire at least eighteen steps at the subject’s usual speed . Geometric parameters (footprint length, footprint width, support area, step, toe out angle, stride breadth) and temporal parameters (stance phase, swing phase, double support phase) have been measured and normalised with respect to height, leg length and speed of progression of each subject. Statistical analysis of data has been performed. Normative data have been obtained by averaging the characteristic parameters of 20 subjects, per sex and per age group. A preliminary analysis of the results shows a slight difference between the two feet, most likely due to the fact that most people are right-handed. l
METHOD OF STATIC LOAD EVALUATION OF THE WRIST JOINT K. Gielo-Perczak Departmentof PhysicalEducation and Recreation, Victoria University of Technology, Melbourne, VIC 3000, Australia A new method is consideredto model the wrist joint structure. The cooperationof the musclesand ligaments servicingthe wrist joint is describedby meansof a statically indeterminatemodel of a variable structure that includesthe influence of the loosejoint as well as the geometry of the joint surfaces.The important considerationsfor the construction of the author’smodel of the wrist joint are as follows: 1) theoretical researchhas been conductedduring wrist deviation, 2) the joint in the deviation plane has been assumedto have two degreesof freedom, 3) the cooperationbetweenthe flexor carpi ulnaris and the flexor carpi radialis muscleshas been assumed,4) cooperation of the collate&e carpi ulnare and collateralecarpi radiale ligamentshas been taken into consideration,5) the analysishas been carried out during radial - ulnar deviation. The analysisof the forces in muscles,ligamentsand the contact forces betweenthe proximal carpal bones and the acetabulumof the ulna and radius, for the two types of wrist joints shows that stressvalues are influencedby the geometry of the joint. An essentialproperty of the author’sproposedmodel of the wrist joint is the possibility of evaluatingthe influence of the geometric parameters;such as defining the cooperatingjoint surfaces,loosenessof the joint, the cross sectionsand the lengthsof musclesand ligaments,the external forces on the hand and the hand position relative to the forearm. The geometry of the joint surfacewas found to be one of the main factors that determinehuman physical strength.