Biomedical subjects

J R Engsberg

Publications and source records attributed to J R Engsberg.

34 records · Page 2Linked to original sources

PubMed1993

A method to determine the range of motion of the ankle joint complex, in vivo.

The purpose of this investigation was to develop a method to quantify a range of motion of the ankle joint complex (AJC) in vivo. A six-degree-of-freedom apparatus was constructed to measure the unconstrained active range of motion of the AJC. Extensive tests evaluating the accuracy of the fixture and data collection protocol were conducted. Euler angles similar to dorsiflexion-plantarflexion, eversion-inversion, and abduction-adduction were used to quantify the range of motion. Significantly greater (p < 0.05) values were found for plantarflexion, inversion, and abduction of a young group of male subjects (n = 7) compared to an elderly group of male subjects (n = 10). In addition, maximum range of motion values did not necessarily occur from the neutral position. In future, this method can be used to help investigate the relationships between AJC motion and injury, changes in range of motion as a function of age, and design of prosthetic ankle joints.

Adult↗

PubMed1993

Differences in ankle joint complex range of motion as a function of age.

The purpose of this study was to determine whether gender- and age-related differences in ankle joint complex (AJC) range of motion (ROM) exist in children (range 9-13 years), adolescents (14-16 years), and young adults (17-20 years), and to compare these data with those published for older subjects (21-79 years) using the same protocol. A total of 120 subjects (58 males and 62 females) ranging in age from 9 to 20 years were tested for AJC ROM using a specifically designed 6 degrees of freedom fixture. All measurements were made with respect to a laboratory coordinate system, and represented assessment of active AJC ROM. Angular displacements for plantarflexion, dorsiflexion, inversion, eversion, abduction, and adduction were digitally recorded and compared. AJC ROMs of females aged 9 to 20 years were generally greater than those for males about all three orthogonal axes. Within each gender, there was a consistent trend for AJC ROM to decrease from a maximum at 14 to 16 or 17 to 20 years to a minimum after age 60 years. The average decrement was greater for females than for males. This study provided evidence to support the contention that age-related and gender differences in AJC ROM do exist. The possibility of minimizing the decline in AJC ROM with age requires further investigation.

Adolescent↗

PubMed1993

Normative ground reaction force data for able-bodied and trans-tibial amputee children during running.

The purpose of this investigation was to develop normative ground reaction force data for able-bodied (AB) and trans-tibial amputee (TTA) children during running. Two hundred AB (mean age 9.4 years, range 7-12) and 21 TTA (mean age 11.1 years, range 5-17) children ran (2.2 m/s +/- 10%) over a force platform. Ground reaction force data were normalized, averaged within groups and plotted to produce force-time curves characterizing the different leg types (i.e. able-bodied, non-prosthetic and prosthetic). In addition, discrete variables characterizing the leg type differences were determined. One way ANOVA determined significant differences between variables and a TukeyB Post Hoc analysis defined which variables were significantly different (p < 0.05). Results generally indicated differences between the three leg types with the non-prosthetic leg indicating greater forces than the prosthetic and AB legs. The results of this investigation provide normative ground reaction force data for both AB and TTA children during running and can be used for comparison with other groups of children.

Adolescent↗

PubMed1992

A CAD CAM method for custom below-knee sockets.

The purpose of this investigation was to develop a numerical method for fabricating prosthetic sockets for below-knee amputees. An optical/laser digitiser scans an amputee's stump and collects three dimensional numerical data describing the surface of the limb and describing specific modification site locations. The numerical data from the laser camera representing the stump and modification sites are altered by the prosthetist using a custom computer aided design software system running on a personal computer. Using the altered numerical data a programme is created for a high resolution numerically controlled milling machine and a mould is made. The prosthetist then fabricates a socket. While the system has been tested with below-knee amputees it has been designed for application in most areas of prosthetics and orthotics. Utilising this method 15 patients were fitted. All patients subjectively stated that their "computer designed" socket fitted better than their conventionally made socket. As the research progressed and experience was gained with the system patients were normally fitted with the first socket iteration. The system overcomes five limitations existing with some of the other numerical systems: 1) accurate high resolution surface topography, 2) specific identification of subject modification sites, 3) flexible, user friendly software, 4) high resolution numerically controlled milling, and 5) integrated expansion to other prosthetic and orthotic areas.

Artificial Limbs↗

PubMed1992

Weight distribution of below-knee amputee and able-bodied children during standing.

The purpose of this investigation was to compare weight distributions of a relatively large number of below-knee (BK) amputee and able-bodied children during two different standing positions. Twenty-one BK amputees and 200 able-bodied children volunteered as subjects for this investigation. Each child stood on a pressure plate and three sets of trial data were collected. One set of trial data was collected with both feet together on the pressure plate and two were collected with feet placed 20cm apart. The total force applied by each foot to the pressure plate was normalised by dividing by subject weight to yield foot force to body weight ratios. Data were separated into forefoot and rearfoot areas, force for the forefoot area was then calculated and normalised by dividing by total foot force to yield forefoot to whole-foot force ratios. Ratios for the two foot placement conditions and for non-prosthetic, prosthetic, dominant, and non-dominant feet were compared using paired t-tests (p < 0.05). Results indicated that: 1) BK amputee children placed more weight on their non-prosthetic limb than their prosthetic limb, yet this was not different from able-bodied children in respect of weight distribution between dominant and non-dominant limbs; 2) approximately 90% of the load on the prosthetic foot was placed on the forefoot; and 3) the load on the non-prosthetic foot was evenly distributed between the forefoot and rearfoot like that of able-bodied children. It was concluded that except for substantially more weight on the forefoot of the prosthetic leg BK amputee children stood in the same way as able-bodied children.

Adolescent↗

PubMed1992

Center of mass location and segment angular orientation of below-knee-amputee and able-bodied children during walking.

This investigation compared the center of mass (COM) locations and segment angular orientations of the gait of below-knee-amputee (BKA) children to those of able-bodied (AB) children. Eleven AB children (mean age, 8.4 years) and three BKA children (mean age, 7.5 years) volunteered to participate as subjects. Film data (100 frames per second) of a typical walking stride, were collected for the children during four experimental sessions held at six-month intervals. Two 16mm cameras were used to obtain frontal and lateral views of the subjects. The same approximate rate of walking (1.2m/s +/- 10%) was enforced for all testing sessions and at least three trials of data were collected for each subject during each session. Segmental endpoints of each subject from the film of each camera were digitized and the direct linear transformation (DLT) method was used to obtain three-dimensional segmental location-time data for a complete stride. These data were then used to determine whole body COM locations and angular orientations for the segments. Discrete values describing normalized locations at touchdown, midsupport, and takeoff were determined for whole body COM and the angular orientation of the trunk, thighs, and legs. In the sagittal plane the COM was lower and more anterior for the BKA children when compared to that of the AB children. This was primarily due to the greater forward flexion of the trunk.(ABSTRACT TRUNCATED AT 250 WORDS)

Amputees↗

PubMed1991

Lower limb intersegmental forces for below-knee amputee children during standing.

The purpose of this investigation was to compare intersegmental knee and hip forces for below-knee amputee (BKA) and able-bodied children during standing. Three unilateral BKA children and 10 able-bodied children (7-9 years) were tested on four separate occasions at six month intervals. Three trials of external force and spatial data during standing were collected from each subject for each session. These data were utilised to determine the intersegmental forces at the knees and hips of the children using a static force analysis. Results indicated that in some instances the intersegmental forces for the BKA children were significantly greater than those of the able-bodied children and in other instances significantly lower (p less than 0.05). In all cases, however, the values were substantially less than corresponding values for walking and running. The effects of the forces upon spatial orientations indicated significant differences between the two groups of children. The frontal plane prosthetic knee angle, the sagittal plane prosthetic and non-prosthetic knee angles, and the sagittal plane trunk angle were all greater for the BKA children when compared to able-bodied children. These differences may be the result of the anatomical structure of the amputee and/or the construction of the prosthesis.

Amputation, Surgical↗

PubMed1991

External loading comparisons between able-bodied and below-knee-amputee children during walking.

The purpose of this investigation was to determine external loading variables that could describe any statistically significant differences between the limbs of below-knee-amputee (BKA) and able-bodied children. Eleven able-bodied children and four BKA children volunteered to participate in this investigation. Force platform data were collected for two consecutive foot falls during two experimental sessions. Significant external load differences existed between the prosthetic limbs and nonprosthetic limbs of BKA children and between limbs of the BKA and able-bodied children. The prosthetic limb generally displayed a subordinate role when compared to nonprosthetic and normal limbs. The nonprosthetic limbs displayed a dominant role when compared to the other limbs. These external loading characteristics of the prosthetic and nonprosthetic limbs may be a logical consequence of the morphologic and functional differences that exist between the groups. It was concluded that as long as the prosthetic limb functions differently from a normal limb, BKA children may have a difficult time walking the same as able-bodied children. It would appear to be advantageous to determine the most appropriate gait pattern for BKA children, given the influence of such factors as prosthetic design, construction, and alignment, rehabilitation, and joint loading.

Adolescent↗

PubMed1990

A function of the talocalcaneal joint during running support.

This study explored the possible function of the talocalcaneal joint during running support to minimize frontal plane rotation of the leg and thereby protect the knee from excessive frontal plane motions. The lower limb was modeled as two rigid segments representing the foot and the leg. The results indicated that for extreme ground-foot angles the talocalaneal joint was able to maintain the knee in a stable position in the frontal plane. It was concluded that the joint may function to minimize frontal plane rotation of the leg and thereby protect the knee from excessive frontal plane motions. The relevance of this function for a below-the-knee-amputee patient lies in the potential for improved prosthetic design.

Ankle Joint↗

PubMed1989

Standing pressure distribution for normal and below-knee amputee children.

Below-knee (BK) amputee children have a different morphology from normal children and amputees may thus have atypical limb loading during standing. The purpose of this investigation was to examine differences in standing ground-shoe pressure distribution between BK and normal children. A pressure plate was used to measure the ground-shoe weight distribution of three BK children and ten normal children during standing. Results indicated that the weight distribution between prosthetic and non-prosthetic limbs of BK children was not significantly different from the feet of normal children. The anterior-posterior weight distribution for the prosthetic and non-prosthetic feet was significantly different from that of the normal children. Further quantification of weight distribution and analysis of more subjects is necessary to determine the benefits, detriments, or irrelevance of these results.

Amputation, Surgical↗

PubMed1988

Predicting talocalcaneal joint orientations from talocalcaneal/talocrural joint orientations.

The purpose of this investigation was to determine the capacity of talocalcaneal/talocrural joint orientations to predict talocalcaneal (TC) joint orientations. A custom designed orientation-loading fixture was used to position the calcaneus and shank with six degrees of freedom, and to apply loads in three orthogonal directions. Three reference pins were rigidly mounted in the calcaneus, talus, and shank segments to provide position data in 243 test situations. Test data were fitted to statistical models using analysis of variance. The models were then used to determine the capacity to predict talus positions from shank positions, both with respect to the calcaneus. Results indicated large between and within specimen variation and was attributed to individual joint morphology. It was concluded that (a) eversion-inversion orientations of the TC/talocrural joint were not always accurate indicators of TC joint orientations, (b) abduction-adduction orientations of the combined joint had the greatest overall influence on TC orientations (thus, monitoring eversion-inversion and abduction-adduction orientations of the combined joint would be more valuable in predicting pronation-supination positions than monitoring only eversion-inversion orientations), and (c) foot categories based on TC and TC/talocrural joint morphology should be developed. They would provide more accurate prediction for specimen foot orientations than prediction from overall average values.

Adult↗

PubMed1987

A biomechanical analysis of the talocalcaneal joint--in vitro.

The talocalcaneal (TC) joint has been a target for injuries and associated with other injuries of the lower extremity. The purposes of this investigation were to obtain a kinematic description of the TC joint, and determine the influence varied displacements and external loads had on this kinematic behavior. A fixture, allowing for a six degree of freedom configuration of the calcaneus and leg and allowing for load application in three orthogonal directions, was constructed. Equivalent screw displacement (ESD) parameters were used to describe TC joint motion. Results indicated external loading had little influence on the ESD parameters and orientation variables accounted for the majority of the influence. Large ESD parameter variation, within- and between-specimens indicated one average TC joint axis location and orientation was not appropriate for describing TC joint motion. It was concluded that foot categories based on TC joint structure and function be developed to provide a foundation upon which to base injury preventative measures, rehabilitative modalities and prosthetic designs.

Analysis of Variance↗

PubMed1987

Kinematic analysis of the talocalcaneal/talocrural joint during running support.

The purpose of this investigation was to obtain a comprehensive description of the kinematic behavior of the combined talocalcaneal/talocrural joint during the support phase of running. Considerable variation in kinematic data was exhibited by a heterogeneous subject sample (N = 5). The results indicated that: eversion/inversion may not be the only rotational component that should be considered when examining total talocalcaneal/talocrural joint motion; the common definitions for pronation and supination do not always accurately describe the relative motion of the shank relative to the calcaneus; and a combined talocalcaneal/talocrural joint behaving as an oblique hinge was not an adequate model for describing the relative motion of the shank with respect to the calcaneus. It was concluded that further investigation is needed to categorize subjects according to common kinematic characteristics. This categorization may be necessary to better understand characteristic variations in normal joint behavior, to diagnose joint pathology, and to prescribe effective injury prevention and rehabilitation modalities.

Adult↗

PubMedDate not supplied

Fate of the psoas muscle after open reduction for developmental dislocation of the hip (DDH).

We evaluated the anatomic and functional consequences of psoas lengthening during operative intervention for developmental dislocation of the hip (DDH). Possible anatomic changes were assessed by magnetic resonance imaging (MRI), and functional assessment included strength determination by an isokinetic dynamometer and gait analysis. Six girls and one boy, ranging in age from 15 to 20 months, had operative reduction of a unilateral DDH. One closed and six open reductions (three anteromedial and three anterolateral approaches) were performed. Follow-up ranged from 4 years 0 months to 9 years 2 months. The cross-sectional area determined by MRI of the lengthened psoas muscles was markedly reduced for all of the six open-reduction patients (three moderate and three severe). Atrophy of the iliacus muscle also was apparent by MRI in five of the six open-reduction patients. Maximum flexion torque, as determined by the isokinetic dynamometer, was diminished on the DDH side for the three patients whose hips were reduced open through the anteromedial approach. Average hip-flexion torque over the entire range of motion was decreased for both anteromedial and anterolateral groups on the operated-on side. Lengthening of the psoas tendon during open reduction of a DDH is associated with considerable atrophy of the psoas muscle.

Atrophy↗

PubMedDate not supplied

Range of motion of the foot as a function of age.

Movement of the foot is essential for human locomotion. The purpose of this paper was to quantify the range of motion of the foot as a function of age and to compare the rage of motion measurements for the foot in a laboratory coordinate system and a coordinate system fixed to the tibia. The measurements were taken in vivo using a range of motion instrument developed by Allinger (University of Calgary, Canada, 1990) from 121 subjects. The results suggest that: (1) the range of motion in general is greater for women than for men in the young adult group; (2) the range of motion in general is in the same order of magnitude for women and men in the oldest age group; and (3) the range of motion is about 8 degrees smaller in dorsiflexion and about 8 degrees higher in plantarflexion for women than for men in the oldest age group. It is speculated that physical activity and common shoe wear are factors influencing the age- and gender-dependent differences in range of motion. Furthermore, it has been shown that the range of motion values measured in a laboratory coordinate system and in a coordinate system fixed in the tibia are different in all directions except inversion. The differences in plantarflexion and dorsiflexion and inversion and eversion are relatively small. However, they are substantial for adduction and abduction. In all cases, the results were bigger for measurements in the laboratory coordinate system compared with the tibia coordinate system, because the movement of the lower leg was included in the measurements in the laboratory coordinate system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Normative ground reaction force data for able-bodied and below-knee-amputee children during walking.

We determined normative ground reaction force data for able-bodied (AB) and below-knee-amputee (BKA) children during walking. Twenty-two BKA and 225 able-bodied children walked over two adjacent force platforms. Average normalized force-time curves were determined for legs of the children for subjective comparisons, and discrete variables were determined for statistical comparisons. No significant differences existed between (a) right and left legs, (b) gender, and (c) age for the AB children. BKA children had an asymmetrical gait pattern with a dominant role of the nonprosthetic limb. This dominant role was related to a greater rate of loading, magnitude of loading, impulse, and time of loading as compared with prosthetic limbs and with the limbs of AB children.

Adolescent↗