Biomedical subjects

Dieter Rosenbaum

Publications and source records attributed to Dieter Rosenbaum.

At least 19 recordsLinked to original sources

PubMed2006

Preliminary normative values for foot loading parameters of the developing child.

The purpose of the present study was to provide normative data for foot loading patterns and foot shape parameters in order to support decisions about the normal or abnormal development of the growing foot during childhood. In a longitudinal design, 90 healthy German children were followed over the course of 6-48 months. The children had a mean age of 15 months at the first appointment and 63 months at the last appointment. The children participated in 11 measurement appointments every 3 months or 6 months. Dynamic foot loading was evaluated with plantar pressure measurements during walking and static footprints were taken to determine changes in foot shape. During the investigation period a significant increase of peak pressure in almost every foot region was observed. Peak pressure of the total foot increased by 92%. Only for the midfoot region a significantly decreased impulse by about 15% per year and a significant decrease of the contact area by 9% per year could be observed. A significant influence of gender was observed for peak pressures and impulses in some foot regions as well as for the midfoot width and the foot shape index. The established database can be used as comparative values for clinical decisions about the normal development.

Child, Preschool↗

PubMed2006

Passive stability characteristics of ankle braces and tape in simulated barefoot and shoe conditions.

BACKGROUND: Ankle sprains are among the most common injuries in barefoot sport activities such as dance, gymnastics, or trampoline. At present, the use of external ankle devices for prevention of ligament injuries for barefoot activities remains unclear. HYPOTHESIS: External ankle devices have a significant loss of passive stability when used without a shoe in barefoot activities. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-five healthy subjects participated in the project (mean age, 26.2 +/- 3.3 years; mean body mass, 71.2 +/- 10.3 kg; mean height, 178 +/- 7 cm). Passive range of motion measurements were performed with 3 different ankle stabilizers (a stirrup brace, a lace-up brace, and tape), as well as 2 different shoe conditions (cutout shoe [simulated barefoot] and normal shoe). RESULTS: In the simulated barefoot condition, a significantly reduced stabilizing effect for inversion and eversion (19% and 29%, respectively) was found for the stirrup ankle brace. Small decreases were noted with the soft brace and tape, but these were not statistically significant. CONCLUSION: The passive stability characteristics of ankle braces depend to a great extent on being used in combination with a shoe. This is especially true for semirigid braces with stirrup design. Therefore, it is recommended that soft braces (like the one tested in the present investigation) be used in barefoot sports for restricting passive range of motion of the foot and ankle complex. CLINICAL RELEVANCE: This study provides useful information for clinicians to select or recommend an external ankle stabilizing device in barefoot sports to restrict passive range of motion of the foot-ankle complex most effectively.

Adult↗

PubMed2006

Accelerometry based assessment of gait parameters in children.

The objective of this study was to examine if spatio-temporal gait parameters in healthy children can be determined from accelerations measured at the lower trunk as has been demonstrated in adults, previously. Twenty children aged 3-16 years, participated in a protocol that involved repeated walks of different distances in an indoor environment. During walking, accelerations were measured by three orthogonally mounted acceleration sensors in a small wireless device (DynaPort MiniMod) that was attached to the lower back. Based on an inverted pendulum approach, spatio-temporal gait parameters and walking distances were computed from the acceleration signals. Results were compared to video observations and known walking distances and durations. Steps were successfully detected in 99.6+/-0.6% of all observed steps (n=5554). On average, walking distance was accurately estimated (100.6+/-3.3%, range 93-106.7%). No correlation was found between the number of miscounted steps and the total number of steps or the age of the subject. It can be concluded that the use of an inverted pendulum model provides the possibility to estimate spatio-temporal gait parameters in children as well as in adults. The method allows an inexpensive and comfortable assessment of gait parameters in children, is applicable in controlled, indoor environments and could be tested for applicability under free living conditions.

Acceleration↗

PubMed2006

Pedographic, clinical, and functional outcome after scarf osteotomy.

The aim of this study was to investigate whether a Scarf osteotomy for hallux valgus correction achieves a good functional restoration with pain reduction, improved mobility, and hallux loading. Therefore, we prospectively studied 32 patients who had a Scarf osteotomy for unilateral hallux valgus. We performed clinical, radiographic, and pedographic evaluations after a mean followup of 33 months to assess clinical and functional outcomes. The mean postoperative American Orthopaedic Foot and Ankle Society score was 89 points. The hallux valgus angle improved from 32.5 degrees to 6.2 degrees , and the intermetatarsal angle improved from 15.5 degrees to 6.6 degrees . The postoperative pedographic patterns showed that the maximum force and impulse decreased under the lateral forefoot and increased under the medial forefoot and hallux. The first ray became more important in the roll-over process. There was a moderate relationship between satisfaction and postoperative hallux valgus angle. The Scarf osteotomy improved the pain situation, the walking capacity, and led to an improved contribution of the hallux in the roll-over process. Therefore, this surgical procedure restores forefoot function and normalizes plantar pressure patterns.

Adult↗

PubMed2005

Preliminary results after total knee arthroplasty without femoral trochlea: evaluation of clinical results, quality of life and gait function.

Evaluation of the clinical and functional results of a new prosthetic knee design with conservation of the physiologic properties of the patellofemoral joint. After total knee arthroplasty there are often patella problems. Some of them may be a result of excessive retropatellar pressure caused by the prosthetic design. Twelve patients with an average age of 68.6 years were evaluated after a follow-up of 16.4 months after implantation of a new prosthetic design. The clinical results were evaluated with the Hospital for Special Surgery Scores (HSS) and the Knee Society Clinical Rating Systems (KSS). Pain was rated on a Visual Analog Scale (VAS). Quality of life was determined with the SF-36 questionnaire. Furthermore, clinical gait analysis was performed with a 3D motion analysis system and force plates as well as surface electromyography of seven lower extremity muscles. The HSS-Score reached a mean value of 79.3 points. The KSS reached 82.3 points for the knee score and 75 points for the functional score. The VAS for pain revealed an average value of 1.7. For the gait analysis only three parameters indicated significant differences between the affected and the contralateral leg. The mean EMG amplitude revealed a significant difference only for the biceps femoris. The clinical and functional outcome of a new prosthesis design show satisfactory results. Even if the presented results appear promising, a further application and long term results are needed.

Aged↗

PubMed2005

The influence of external ankle braces on subjective and objective parameters of performance in a sports-related agility course.

With lateral ankle sprains being the most frequent sports-related injury, there is an evident demand for the preventive measures in active individuals with chronic ankle instability. Braces are commonly used for prevention and treatment of ankle injuries. Various investigations-mostly performed with healthy subjects-focused on this problem, yet they often compared only a few models or used only limited testing procedures. However, controversy exists whether braces affect sports performance. The purpose of the present study was to compare the effects of ten different ankle braces-one rigid, five semirigid, four soft models-in a comprehensive evaluation with multiple testing procedures in 34 subjects with self-reported chronic ankle instability. The multiple testing procedures evaluated objective performance-related parameters and subjective parameters related to comfort and stability. The subjects performed an agility course with maximal effort. The course included a vertical jump and a cutting maneuver, both on a force platform, a single leg hopping test on level and inclined plates, a combined straight and curve sprint and sidesteps. Three valid trials were measured and averaged for each brace and every subject. Subjective aspects were evaluated with a questionnaire about handling, perceived restrictions, support and comfort; it was completed after each brace was worn and tried. With regard to the objective parameters, no significant differences were found between the braces except for the rigid brace which showed decreased values for the vertical jump and longer times for the other tests compared to all other braces. The subjective evaluation of the braces revealed significant differences with respect to comfort and handling and therefore, permitted a distinction between semirigid and soft braces. Although significant differences between braces were found in subjective performance restriction, no significant differences were revealed in the objective evaluation. From that point of view, patients could choose a brace model according to their individual needs. A comfortable brace might have a positive influence on the athlete's state of mind although other aspects like the brace's stabilizing effect play an additional role and should also be taken into account for recommendation of braces.

Adolescent↗

PubMed2005

Retropatellar contact characteristics before and after total knee arthroplasty.

PURPOSE: Qualitative analysis of the retropatellar contact characteristics after total knee arthroplasty. MATERIAL AND METHODS: Six cadaveric knees were investigated before and after implantation of a Genesis I knee prosthesis without and with patellar resurfacing in different positions. Joint contact characteristics were evaluated with Fuji Prescale film type 'Super Low' and analyzed qualitatively in nine quadrants. The pressure was determined from a 5-s loading duration in four different knee positions between 45 degrees and 120 degrees of flexion. The femoral component of the prosthesis was implanted in neutral as well as in internal and external rotation. A quadriceps force of 280 N with either a predominant medial or lateral pulling direction was applied. RESULTS: Without prosthesis the largest contact area is between 60 degrees and 90 degrees of flexion. A lateral muscle force direction as well as an external rotation increased the frequency of loading in the medial quadrants. After implantation of the prosthesis the central and superior quadrants were predominantly contacted irrespective of the flexion angle. No marked differences between the flexion angles were found. Implantation of the patellar resurfacing led to contact in the three central quadrants. CONCLUSION: Implantation of the endoprosthesis leads to increased contact in slight and extreme flexion angles. Especially the central areas are increasingly loaded. No predominant influence of the rotation of the femoral component or the direction of the muscle pull was found. An improved distribution of the contact area could not be demonstrated after patellar resurfacing.

Aged↗

PubMed2004

Clinical and functional results after the rehabilitation period in minimally-invasive unicondylar knee arthroplasty patients.

The objective of the present study was to analyze the clinical and functional outcome after minimally-invasive implantation of a Repicci-type unicompartmental sledge prosthesis . In 29 patients with primary unicompartmental knee osteoarthritis, 29 replacements of the medial compartment and four of the lateral compartment were performed using the minimally-invasive technique with the metal-backed and the all-polyethylene versions of the Repicci sledge prosthesis. Electromyography (EMG) of standardized locations was measured with the MyoSystem 2000 and analyzed with Myoresearch software. Gait analysis was performed with a six-camera motion analysis system and force platforms. Established clinical and quality of life (SF-36) scores were used to compare patients with 11 healthy age-matched individuals. The Repicci sledge prosthesis led postoperatively to functional results that were in the range of healthy joints, and superior to sledge prostheses of a different design. Gait and balance parameters were comparable to the control group, whilst electromyographically lower amplitudes were found in the patients than the controls and in the operated legs as compared to the non-operated legs. Many parameters of quality of life and activity were comparable to age-matched healthy individuals, and quality of life was superior to total knee replacement. When implanted using a minimally-invasive technique and with suitable patient selection, the Repicci sledge led to functional results comparable to those of healthy joints and gait parameters comparable to those of healthy individuals. The level of evidence is Level III, retrospective cohort study.

Aged↗

PubMed2004

Correlations between the step activity monitor and the DynaPort ADL-monitor.

OBJECTIVE: This study was performed to evaluate correlations between the DynaPort activity of daily living monitor and the step activity monitor. DESIGN: Experimental study with repeated measures. BACKGROUND: Physical activity becomes more important to assess quality of life, e.g. after clinical interventions such as joint replacement surgery. METHODS: Nine subjects wore both devices simultaneously for two days. Limitations and technical problems caused by the devices were assessed by a questionnaire. Correlation coefficients were calculated between parameters derived from both instruments. RESULTS: Only small limitations and problems were reported. Significant correlations were found between the number of steps (step activity monitor) and the percentage of locomotion (DynaPort) (r=0.95), between the number of steps and the physical activity index (DynaPort) (r=0.71) and between the physical activity index and the percentage of locomotion (r=0.76). Wilcoxon-tests between the first and second measurement of each subject did not reveal significant differences but correlation coefficients were poor (r=0.16-0.36). CONCLUSIONS: After one day of simultaneously wearing both devices, the percentage of locomotion can be obtained using only the step activity monitor for additional days. Poor correlations between the first and the second measurements of each subject underline the necessity to record further days to acquire the level of human physical activity.

Activities of Daily Living↗

PubMed2004

The effects of rocker sole and SACH heel on kinematics in gait.

The rocker sole and solid-ankle cushion-heel (SACH) heels are the most commonly prescribed external shoe modification. Only a limited number of scientific evidence exists to support these interventions in clinical practice. The objective of this study was to determine the effects of rocker soles and SACH heels on kinematics during gait. In this study, we investigated the gait parameters during level walking, stair climbing and stair descending in healthy volunteers and assessed the effects of the modified shoes on the motion of the forefoot and hindfoot compared with the traditional shoes. Eleven normal subjects participated in this study. A six-camera motion analysis system was used to capture motion trajectories. The three-dimensional (3D) coordinates of the markers were used to calculate the angles of flexion-extension, valgus-varus, and internal-external rotation at the hindfoot and forefoot joints in a gait cycle by the custom software for foot kinematic analysis. The results showed that the rocker soles offer several advantages from the viewpoint of gait kinematics. The forefoot joint excursion in sagittal plane while wearing rocker shoes was significantly less than that while wearing traditional shoes during level walking, stair climbing and stair descending. It means that they could mimic the action of the forefoot joint, aid in roll off, and simulate forefoot dorsiflexion. Since the bony structures mechanically link the forefoot joint and hindfoot joint to a triplanar axis of motion, they could be used whenever there is minimal or no motion at the forefoot joint or hindfoot joint, because of, for example, fusion, fracture, cast immobilization, orthosis design, pain, or arthritis.

Adult↗

PubMed2004

Evaluation of early walking patterns from plantar pressure distribution measurements. First year results of 42 children.

This study evaluated developmental changes of foot and gait during the first year of independent walking. In a longitudinal design, plantar pressure distribution patterns were measured with a capacitive platform every 3 months in a group of 42 normal children. The first significant changes were already found after a few weeks of independent walking. The development of the longitudinal arch correlated with significantly reduced midfoot loading parameters even though the changes showed a wide interindividual variation. This study illustrates that a child's foot goes through significant changes in shape and loading characteristics once the child starts to stand and walk. Some children showed a fairly mature appearance of the plantar pressure pattern after 1 year while others retained a more immature loading pattern.

Anthropometry↗

PubMed2004

Reduced plantar sensation causes a cautious walking pattern.

The aim of this study was to investigate the influence of reduced plantar sensation on gait patterns during walking in 20 healthy subjects (25.9 +/- years, 61.6 +/- 11.5 kg, 178 +/- 9.5 cm) with no history of sensory disorders. Force plate measurements, electromyography (EMG) measurements and a three-dimensional movement analysis were performed simultaneously during barefoot walking before and after reduction of plantar sensation using an ice immersion technique. The results show that reduced plantar sensation leads to significant changes in gait patterns that are present at the ankle, knee and hip joint and indicate a more cautious ground contact and push-off with modified EMG and motion patterns.

Adult↗

PubMed2004

The influence of muscle fatigue on electromyogram and plantar pressure patterns as an explanation for the incidence of metatarsal stress fractures.

BACKGROUND: Stress fractures are common overuse injuries in runners and appear most frequently in the metatarsals. PURPOSE: To investigate fatigue-related changes in surface electromyographic activity patterns and plantar pressure patterns during treadmill running as potential causative factors for metatarsal stress fractures. STUDY DESIGN: Prospective cohort study with repeated measurements. METHODS: Thirty experienced runners volunteered to participate in a maximally exhaustive run above the anaerobic threshold. Surface electromyographic activity was monitored for 14 muscles, and plantar pressures were measured using an in-shoe monitoring system. Fatigue was documented with blood lactate measurements. RESULTS: The results demonstrated an increased maximal force (5%, P < .01), peak pressure (12%, P < .001), and impulse (9%, P < .01) under the second and third metatarsal head and under the medial midfoot (force = 7%, P < .05; pressure = 6%, P < .05; impulse = 17%, P < .01) toward the end of the fatiguing run. Contact area and contact time were only slightly affected. The mean electromyographic activity was significantly reduced in the medial gastrocnemius (-9%, P < .01), lateral gastrocnemius (-12%, P < .01), and soleus (-9%, P < .001) muscles. CONCLUSION: The demonstrated alteration of the rollover process with an increased forefoot loading may help to explain the incidence of stress fractures of the metatarsals under fatiguing loading conditions.

Adult↗

PubMed2004

Gender-specific differences of the foot during the first year of walking.

BACKGROUND: It is is well established that gender-specific differences in foot shape exist in adults. However, no information is available whether these differences are present already in children's feet and at what stage in the development these changes become evident. METHODS: Plantar pressure patterns and footprints of 42 healthy infants (20 male, 22 female) were evaluated over the course of one year and compared regarding gender-specific differences. The age at initial evaluation of the children was 16.1 months, and they were evaluated every 3 months. Anthropometric data, foot shape, and foot loading parameters for the whole foot, as well as for selected regions of interest, were evaluated. RESULTS: Significant differences in the foot shape and dynamic foot loading parameters were noted between boys and girls already at this young age. Boys demonstrated a broader midfoot, indicating a lower arch. Girls showed a more pronounced dynamic loading, especially in the heel and forefoot regions. CONCLUSIONS: The differences seen in this study should be taken into account by the shoe industry responsible for the design of children's shoes to support healthy development of the growing foot. Foot disorders are not only caused by hereditary factors but may be due to disturbances during foot growth and development. Since today's society is dependent on wearing shoes for foot protection, shoes should be designed not only according to the fashion demands of the customers but also to the biomechanical needs. Therefore, it is important to ensure that shoes fit the shape of the feet, which is different for boys and girls already when walking begins.

Anthropometry↗

PubMed2003

Changes in talocrural joint contact stress characteristics after simulated rotationplasty.

In order to assess the changes in talocrural joint contact stress after rotationplasty, 10 lower-leg cadaver specimens were axially loaded with 600 N and investigated in two loading situations: (1) Normal loading with a plantigrade foot; (2) in an equinus position of a simulated rotationplasty. Joint contact stress in the talar facet of the talocrural joint was determined with Fuji Prescale film cut to size and analyzed with digital image analysis for joint contact area, mean and peak pressure, contact force, and location of the load application on the trochlea tali. The results demonstrate a significant transfer on the loading zone to the posterior part of the talus (p = 0.005), a significant reduction of the contact area (p = 0.005) and force (p = 0.005), and a significant increase of the mean (p = 0.022) and maximum pressures (p = 0.013). These results indicate that the rotationplasty causes pronounced changes in joint loading characteristics.

Aged↗

PubMed2003

Proprioception with bicondylar sledge prostheses retaining cruciate ligaments.

The current study was designed to evaluate the proprioceptive performance of the knee after implantation of bicondylar sledge prostheses in comparison with contralateral knees and knees of healthy control subjects. After implantation of a sledge prosthesis in the medial and lateral condyles of a knee retaining all ligaments, 15 patients were evaluated clinically and by proprioceptive testing. Clinical examination was done using common scoring systems. Proprioceptive performance was examined using sway measurements during single-leg stance on a force platform. Eleven healthy subjects of the same age served as a control group. Clinical results of both groups differed significantly in all applied scores, except for the subcategories gait, muscle force, and pain. Sway measurements did not differ between right and left legs of subjects in the control group. The patients' surgically treated legs had slightly higher values than the control group, but a statistical significance was not found. Statistical analysis revealed no significant correlation between clinical scores and sway measurement results. Total knee arthroplasty that retains all intraarticular ligaments achieves proprioceptive results comparable with healthy subjects of the same age.

Aged↗

PubMed2003

The main function of ankle braces is to control the joint position before landing.

The aim of the present investigation was to evaluate the stabilizing effect of 10 different ankle braces during simulated inversion on a tilting platform. Twenty-five subjects participated in the study (23 +/- 3 yrs, 71 +/- 12 kg, 177 +/- 9 cm). Ten commercially available ankle braces and a trapdoor in combination with a goniometer system that measured hindfoot inversion inside the shoe were used. Inversion was subdivided into a free fall and a maximum inversion phase. Results showed that all braces restricted inversion significantly between 51% and 15% compared to the no-brace condition but distinct differences between models were found. Maximum inversion angle and inversion velocity were lower for those braces that restricted inversion most effectively during the free fall phase. Reaction times of the peroneus longus did not appear to influence the degree of inversion. Relatively constant differences between free fall and maximum inversion angles for all models (between 6 degrees and 10 degrees) and a high correlation between these two parameters suggests that the main function of ankle braces is to restrict inversion during the free fall phase and not at the extremes of motion.

Adult↗

PubMed2002

ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion--part I: ankle, hip, and spine. International Society of Biomechanics.

The Standardization and Terminology Committee (STC) of the International Society of Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currently a lack of standard for reporting joint motion in the field of biomechanics for human movement, and the JCS as proposed by Grood and Suntay has the advantage of reporting joint motions in clinically relevant terms. In this communication, the STC proposes definitions of JCS for the ankle, hip, and spine. Definitions for other joints (such as shoulder, elbow, hand and wrist, temporomandibular joint (TMJ), and whole body) will be reported in later parts of the series. The STC is publishing these recommendations so as to encourage their use, to stimulate feedback and discussion, and to facilitate further revisions. For each joint, a standard for the local axis system in each articulating bone is generated. These axes then standardize the JCS. Adopting these standards will lead to better communication among researchers and clinicians.

Biomechanical Phenomena↗