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Papers by Gert-Peter Brüggemann

Journal of Biomechanics, 2005

Regarding the strain and elongation distribution along the tendon and aponeurosis the literature ... more Regarding the strain and elongation distribution along the tendon and aponeurosis the literature is reporting different findings. Therefore, the purpose of this study was to examine in vivo the elongation and the strain of the human gastrocnemius medialis tendon and aponeurosis simultaneously at the same trial during maximal voluntary plantarflexion efforts. Twelve subjects participated in the study. The subjects performed isometric maximal voluntary contractions of their left leg on a Biodex-dynamometer. The kinematics of the leg were recorded using the Vicon 624 system with 8 cameras operating at 120 Hz. Two ultrasound probes were used to visualise the tendon (myotendinous junction region) and the distal aponeurosis of the gastrocnemius medialis respectively. The main findings were: (a) the absolute elongation of the gastrocnemius medialis tendon was different to that of the aponeurosis, (b) the strain of the gastrocnemius medialis tendon did not differ from the strain of the aponeurosis, (c) during the "isometric" plantarflexion the ankle angle exhibited significant changes, and (d) the non-rigidity of the dynamometer arm-foot system and the coactivity of the tibialis anterior both have a significant influence on the moment exerted at the ankle joint. Thus the strain of the human gastrocnemius medialis tendon and aponeurosis estimated in vivo using two-dimensional ultrasonography is uniform. To calculate the elongation of the whole tendon it is necessary to multiply the strain calculated for the examined part of the tendon by the total length of the tendon.

Human Movement Science, 2012

Clinical Biomechanics, 2005

Joint stabilisation processes have been mainly studied comparing groups or joints with different ... more Joint stabilisation processes have been mainly studied comparing groups or joints with different stabilities and mainly focusing on one single parameter. The inherent limitations are discussed and a study, where kinematic, kinetic and electromyografic parameters gained from sudden tilt tests were measured, is presented. The response of 24 subjects to sudden lateral and medial tilts of the foot during one legged stance were compared. A three-dimensional foot model was utilised to describe ankle and foot motion. Electromyografic signals of six muscles of the lower limb as well as the horizontal ground reaction forces were analysed. Forefoot to rearfoot motion was faster and greater than ankle motion. In general medial tilts showed lower motion amplitudes and angular velocities than lateral tilts but higher horizontal ground reaction force integrals. The electromyography patterns where similar for both conditions. However, a specificity of the muscular response could be identified in the electromyography amplitudes. The higher mediolateral ground reaction forces, together with the reduced kinematic and no general increase in muscular activation in medial tilts suggest, that passive structures seem to be able to counteract destabilising forces and thus reduce the otherwise needed muscular activation.

Footwear Science, 2017

Only a few studies have measured the movement of the calcaneus inside the shoe during running, an... more Only a few studies have measured the movement of the calcaneus inside the shoe during running, and those that have done so have focused on the frontal plane of motion. This study's objective was to determine the three-dimensional (3D) movement of the calcaneus inside the shoe during running. A secondary objective was to determine if calcaneus movement differs between neutral and support shoes. Ten participants ran at 3.5 m/s in two shoes: a neutral and a support shoe. Right rearfoot kinematics were measured using reflective markers affixed to the shoe heel counter and to the skin of the rearfoot inside the shoe. 3D segment angle ranges of motion were calculated and compared across the shoe heel and calcaneus conditions, and across the two shoe conditions. The movement of the calcaneus compared to the shoe heel was not different in the frontal plane, but was significantly different in the transverse plane, with the calcaneus adducting by 4° more than the shoe heel. The calcaneus also moved significantly more than the shoe in the sagittal plane. Results were similar across the shoe conditions except in the frontal plane where less rearfoot eversion was measured in the support compared to the neutral shoe. The results from this study highlight an opportunity for the development of footwear technologies that can guide calcaneal adduction. Additionally, markers on the shoe heel counter may be appropriate for measuring motion of the foot inside the shoe in the frontal plane, but not the transverse plane.

Caine/Gymnastics, 2013

ABSTRACT

Medicine & Science in Sports & Exercise, 2002

The purposes of this study were a) to develop a model of the foot capable of describing the foot ... more The purposes of this study were a) to develop a model of the foot capable of describing the foot motion during dynamic movements and b) to study the influence of different mats on foot motion during landing in gymnastics. Six female gymnasts (height: 1.63 +/- 0.04 m, weight: 58.21 +/- 3.46 kg) participated in this study. All six gymnasts carried out barefoot landings, falling from 80 and 115 cm onto three mats each with a different stiffness (hard, medium, and soft). Three synchronized digital high-speed video cameras (250 Hz) captured the motion of the left shank and foot. At the same time, the reaction forces between mat and foot at the forefoot and rearfoot were measured by two instrumented insoles (Paromed, 1000 Hz). The kinematics of the tibiotalar, talonavicular, and calcaneocuboid joints were examined. The lower leg and the foot were modeled by means of a multi-body system, comprising seven rigid bodies. For each joint, two joint coordinate systems attached on each of the connected segments were defined. The mat stiffness did not show any influence on the maximal reaction forces or on the kinematics of the tibiotalar joint. For the soft mat, higher maximal eversion angles at the talonavicular and the calcaneocuboid joints were measured. The relative motion between forefoot and rearfoot was influenced by changing mat stiffness. Therefore, the construction of the mat influenced the motion of the foot. The observation of only the tibiotalar joint is not enough when studying the influence of different mats on foot motion. The functional benefit of the mechanical advantages of a soft mat (higher energy absorption) includes a decrease in stability. The surface of the landing mat should, therefore, be reinforced by a stabilizing mechanism.

This presentation describes the enormous development of technology and methodology in biomechanic... more This presentation describes the enormous development of technology and methodology in biomechanics of sports related to performance and sporting goods, apparatus and equipment. It will critically discuss the relevance and importance of technology for performance and it’s enhancement on one hand and the impact of human resources and training on the other hand. Technology of sporting goods and sport equipment is not only developed to enhance performance but also to decrease the risk of injury during sport activity and exercise. The effects of advanced technology will critically be reviewed regarding to their efficiency and sustainability to the athlete in elite and recreational sports and exercise.

In this study two groups of operatively-treated ACL-rupture patients (patella tendon graft (BPTB)... more In this study two groups of operatively-treated ACL-rupture patients (patella tendon graft (BPTB) or semitendinosus graft (ST) with a similar rehabilitation process were compared regarding their muscle strength capabilities, and the clinical outcome. 69 patients (mean age 31 years) were selected according to the Lysholmscore. Twenty-eight of the subjects were in the 3rd to 6th month postsurgery (MPS) (Gr. ST I, Gr. BPTB I), 20 patients were in the 6th to 12th MPS (Gr. ST II, Gr. BPTB II) and 21 patients in the 12th to 24th MPS (Gr. ST III, Gr. BPTB III). The subjects had to perform concentric contractions of the extensor and flexor muscles of the knee, hip and ankle at 60 °/s. In addition, the knee muscles were isometrically tested at knee angles of 0°and 45°. The analysis of the muscular strength capabilities revealed significant differences (P<0.05) in maximal isokinetic torque (M max,con) for the knee extensor muscles between both the two reconstruction techniques in groups ST II/ BPTB II and ST III/ BPTB III favouring the ST method. The clinical tests (OAK evaluation form) cannot provide a criterion clearly favouring one of the studied techniques. When comparing the muscular strength capabilities, the isokinetic torgue torque of the knee extensors for the intervals 6 to 12 and 12 to 24 MPS, the BPTB patients appear to be weaker than the ST patients. This can be attributed to the traumatic lesion of the patella. Whereas the BPTB patients also show strength deficits when comparing the affected with the unaffected side, the ST patients demonstrate better regeneration of their muscular strength capabilities.

The purpose of this study was to identify the general and individual biomechanical response to in... more The purpose of this study was to identify the general and individual biomechanical response to increased vertical loading with a particular emphasis on the knee joint in running. Biomechanical analysis was performed in three different loading conditions (100%, 110%, 120% body weight) by means of a standard inverse dynamics procedure using a Vicon Nexus system and an instrumented treadmill. Increased vertical loading was accompanied by increased peak internal knee abduction moments and a small increase (0.6°) of knee adduction angles. Two adaptation mechanisms could be identified, differing with respect to the increase of peak vertical GRF and abduction moments. It might be that runners aim at maintaining their habitual joint motion path, choosing a strategy that corresponds to their capacities to resist additional external loads.

Während der aufrechten Fortbewegung halten die großen Beinstreckmuskeln an Hüft-, Knie- und Sprun... more Während der aufrechten Fortbewegung halten die großen Beinstreckmuskeln an Hüft-, Knie- und Sprunggelenk unseren Körper aufrecht und beschleunigen ihn vorwärts. Zahlreiche Studien befassten sich mit der Anpassung dieser Muskeln an ein isometrisches Maximalkrafttraining (z. B. Hettinger & Müller 1953; Komi et al. 1978; Young et al. 1985). Das letzte Glied in dieser kinetischen Kette, der Bereich zwischen Sprunggelenk, Zehengrundgelenk und den Zehen, ist in der Literatur nur unzureichend beschrieben. Ziel der Studie war die Untersuchung der funktionellen Anpassung der Zehenbeuger an einen erhöhten mechanischen Reiz und die Effekte auf die mechanische und sportmotorische Leistung bei Gang, Lauf und Sprung. 15 Männer führten über 7 Wochen an einem Dynamometer ein Maximalkrafttraining der Zehenbeuger durch (90% MVC, 4 Tage/Wo, 4 Serien, 5 Wh, 3s Belastung, 3s Pause, insgesamt 560 Kontraktionen). Die Kontrollgruppe trainierte nicht. Vor und nach der Intervention wurden sowohl Maximalkraft...

Biomedical Engineering / Biomedizinische Technik, 2015

Biomechanical analyses of the stress distribution and the force transfer in the human knee are es... more Biomechanical analyses of the stress distribution and the force transfer in the human knee are essential to better understand the aetiology of joint diseases. Accuracy studies of commonly used capacitive or resistive-based stress distribution measurement systems have led to severe problems caused by an inaccurate experimental setup. For instance, in one study, overestimations of the measured forces in the sensor’s centre were reported. Therefore, the primary aim of this study was to investigate the ability of capacitive and resistive-based sensors to measure forces in a homogenous pressure environment and the secondary goal was to analyse the influence of different calibration materials on the measurement accuracy. A Novel pressure vessel and metal indenters covered with different rubber materials were used in combination with a material testing machine to load the sensors. Four different linearly increasing nominal forces (925–3670 N) were applied and the deviations between the nom...

The aim of this study was to analyze the effect of an anklefoot-orthosis (AFO) on the knee adduct... more The aim of this study was to analyze the effect of an anklefoot-orthosis (AFO) on the knee adduction moment as an alternative conservative treatment for medial knee osteoarthritis. Subjects with knee varus alignment were analyzed in five different conditions: without orthotic, with laterally wedged insoles and with an AFO in three different adjustments. Kinetic and kinematic data were collected using 3D gait analysis. Significant decreases in the knee adduction moment, knee lever arm and knee joint angle in the frontal plane were observed with the AFO, indicating load reduction in the medial knee compartment.