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Biomedical subjects

J U Baumann

Publications and source records attributed to J U Baumann.

At least 19 recordsLinked to original sources
PubMed1998

Three-dimensional analysis of the skeleton of the lower extremities with 3D-precision radiography.

A tool is presented to assess the lower extremities using linear and angular measurements under full weight-bearing in three dimensions. While the patient is standing on both legs in a frame representing a calibrated three-dimensional (3D) space, standard radiographs of the hips (anteroposterior view, AP) as well as of the knees (AP and lateral views) are taken. The coordinates for localisation of the malleoli are determined clinically in respect to the coordinate system of the 3D space. Characteristic landmarks are digitized on the calibrated radiographic films, and the so determined coordinates of the malleoli are fed into the computer together with the femoral anteversion, which is ascertained from an additional Dunn-Rippstein II view. All angles of the lower extremities in the frontal or sagittal planes as well as torsions are measured with an error of less than +/- 5 degrees and the lengths, with an error of less than 5 mm. The data are presented in a stick figure diagram and listed in a table. With this device, it is possible to determine simultaneously the angular values and bone lengths under full weight-bearing. The method has proved its value for planning corrective surgery of complex bony deformities of the lower extremities. An accuracy evaluation is reported which includes intra- and interobserver reliability of results.

Adult↗
PubMed1994

[Gait changes in elderly people].

Age-associated changes in gait produce a decrease in walking velocity, predominantly caused by a reduction in the length of the step and to a lesser degree in cadence. The length of the step becomes shorter because of impaired balance, diminished muscle strength and muscle contractures that decrease the joint range of motion. Impairment of the quality of their gait is a major risk factor for falls in the elderly with subsequent minor or major injuries. Age-related changes in gait of elderly people must be taken into account when planning orthopedic surgical procedures and applying orthopedic devices such as orthoses and lower extremity prostheses. Exercise programs to maintain and improve muscle strength, equilibrium reactions as well as neuromotor coordination have proved effective in postponing and correcting age-related gait instability and in increasing walking velocity as well as mobility in daily life.

Aged↗
PubMed1992

[Treatment concepts in knee malposition within the scope of primary neurologic diseases].

Disease and trauma to the central and peripheral nervous system can result in various disturbances to the stability and mobility of the knee joint. The aims of orthopaedic treatment in flaccid paralysis, spasticity, rigidity, athetosis and ataxia are discussed. The effect on the musculo-skeletal system is most severe when the damage occurs prenatally. The tendency to deformity in perinatal cerebral spastic disorders of movement can be considerably reduced by early systematic functional treatment. Active and passive exercise, corrective and reflex inhibiting casts and orthoses have proved their value in the prevention and treatment of muscle contractures in flaccid paralysis and spasticity. The dangers of treatment, such as subluxation of the knee and hip joint, osteoporotic fractures, and traction paralysis, must be taken into account. Muscle contractures often hinder function, both in spasticity and in flaccid paralysis, more than the underlying disease. The operative treatment of flexion contractures and impaired knee flexion in the swing phase of the step is discussed. Gait analysis facilitates the planning of treatment. The hip, knee and ankle joints must be treated as a single functional unit.

Cerebral Palsy↗
PubMed1992

[Forces and turning moments of hip and knee joints in locomotion].

In order to be helpful to orthopedic surgeons in planning operations, and providing quality control, gait analysis must provide information on forces and moments at major joints because kinematic data alone have proved to be unsatisfactory. A practical procedure for this purpose was developed and applied to 20 children and young adults, using the inverse dynamic approach. Segmental body volumes were obtained by stereophotogrammetry. Together with density values, this permits individual calculation of segmental mass center positions even in the presence of severe deformity. Segmental anatomical coordinate systems were defined and tagged by skin markers. Subsequent stereophotogrammetric gait recording by high-speed cameras and 3D force plates allowed the calculation of reactive forces and moments with their changing values over each gait cycle. For the two peaks of force transmission in the early and late stance phases, vector diagrams demonstrate 3D components of forces and moments as related to the anatomy of the thigh and shank of a normal young adult. The peak reaction force component in the longitudinal axis during initial loading about reaches body weight, the anteroposterior force 2/5th and the mediolateral component 1/25th of body weight.

Adolescent↗
PubMed1988

[Neuro-orthopedic problems in the area of the elbow joint].

Neuromuscular impairment of elbow function directly affects the activities of daily living as well as the ability to work in many patients. A series of typical pathophysiological syndromes occur in the region of the elbow as immediate or late results of local trauma or more distant injuries to the brain, cervical cord, cervicobrachial plexus, or peripheral nerves. The operative management is determined by the pathophysiology of the lesions and the anatomical relationship between the muscles and the neurovascular structures at the elbow. These syndromes and their treatment are reviewed.

Elbow Joint↗
PubMed1986

[Treatment of pediatric spastic foot deformities].

The pathophysiology of gait under the influence of cerebral-spastic leg musculature and the resulting biomechanical effects are demonstrated. The latter must be taken into account for successful treatment of functional disturbances and in the shape of the feet in children with cerebral-spastic disturbances in movement. Co-contractions in antagonistic muscle groups of the lower extremities during the second half of the stance phase, the propulsion period of the step, are the main obstacles to achieving efficient gait. The causes lie in the spastic increase of the muscle stretch reflex as well as in a defect in the reciprocal inhibition of antagonistic muscle groups. Moderate equinus gait and an increase in the normal differences in the development of force by the dorsal and plantar flexing muscles represent effective physiological compensation for these disturbances. The common secondary changes in the shape of the foot resulting from spasticity and contractures of the muscles require long-term planning of treatment, including physiotherapy, plaster casts, plastic orthoses, orthopedic shoes and, in some cases, operations, which should be delayed as long as possible during the growth phase. Premature lengthening of the Achilles tendon regularly results in iatrogenic foot deformities.

Casts, Surgical↗
PubMed1986

[Combined lateral ligament-plasty and calcaneus osteotomy in recurrent foot dislocation].

The risk of a supination trauma is particularly high in patients with pathological calcaneus varus as opposed to physiological calcaneus valgus. If in these patients only the lateral ligaments are operatively treated after a trauma, there is a high incidence of recurrence, as the abnormal position of the calcaneus means that the supinating forces acting laterally have a stronger effect than in normal cases. We therefore suggest a combination of fibulotalar syndesmoplasty with osteotomy of the calcaneus according to Dwyer in such cases. In the last 7 years we have carried out this operation eight times with no recurrence in any of these patients so far. In four patients, a gait analysis was performed. It was established that the abnormal floor reaction forces seen in the presence of calcaneus varus normalize following the operation.

Adolescent↗
PubMed1980

Distal hamstring lengthening in cerebral palsy. An evaluation by gait analysis.

Distal elongation of the hamstrings was performed for contracture due to neurogenic disorders in 66 patients. A follow-up study on 34 of the patients with cerebral palsy is reported here. The success of the operation was judged by functional evaluation including joint measurement and gait analysis. The advantages of this operation and the need for prolonged aftercare are discussed.

Adolescent↗
PubMed1980

Ankle joint fusion -- determination of optimal position by gait analysis.

The influence of the position of the ankle joint on the gait pattern was examined in 12 patients. All had stable unilateral tibio-talar arthrodesis for posttraumatic osteoarthrosis. Six were fused in 8 to 12 degrees of plantar flexion, six in neutral or calcaneus position. A total of 48 steps with and without shoes was analyzed and compared statistically with 24 steps on the normal side. After arthrodesis in equinus position, lower leg and knee take up an unfavourable position before heel-off, with the result that the center of gravity is elevated more than normal. This is particularly the case barefoot but is also observed when shoes are worn. On the basis of gait evaluation, ankle joint arthrodesis should be performed in the neutral position for both men and women.

Ankle Joint↗
PubMed1980

[Gait in the aged (author's transl)].

Typical changes in the gait movements of older people are produced by a decrease in the elasticity of muscles and ligaments, reduced joint mobility and a diminishing quality of equilibrium reactions. They lead to a slower speed of walking with increase in the percentage of the double-stance phase during the gait cycle. Floor reaction forces as measured by a pair of force plates are compared between a 24 year old and a 92 year old woman. A pronounced failure in the older person is the irregular path of the frontal forces which have stabilising functions.

Adult↗
PubMed1979

[Dwyer's calcaneal osteotomy for varus deformity of the foot. (A follow-up study including gait analysis) (author's transl)].

A follow-up study on 20 patients one to 9 years after lateral wedge resection of the calcaneus according to Dwyer is reported. In 18 feet with neurogenic varus deformity of the hind foot, the angle between the axis of the lower leg and the heel was altered from 11.4 degrees +/- 1.4 degrees SD varus to a normal value of 5.9 degrees +/- 0.9 degrees SD valgus. The position of the calcaneal tuberosity was changed from 6.7 degrees +/- 1.1 degree SD varus to 0.1 degree +/- SD varus in 7 congenital club feet. The osteotomy reduced accompanying deformities of pes cavus and pes adductus in the operated children.

Adolescent↗