THE INTERFACE BETWEEN CLINICAL AND PERFORMANCE RELATED BIOMECHANICS – AN EMERGING RESEARCHER’S JOURNEY

The presentation will describe the journey my career has taken so far, using three main themes, which have been selected to reflect my experience to date. The examples demonstrate how sports biomechanics can contribute towards developing new knowledge in a multidisciplinary setting with specific reference to the interface between clinical practice and performance related biomechanics. The three main themes will include: Clinical Biomechanics (ACL injury), Adapted Performance (Amputee Sprinting), and Environmental Interaction (Artificial Turf). The initial theme Clinical Biomechanics, emerges from my work at the University of Salzburg, exploring ACL-injury and a conservative treatment (RegentK), where acute effects of ACL-injury on gait and lower limb impacts will be discussed. The second theme will examine the contemporary aspect of Adapted Performance, specifically the use of blades in amputee sprinting during the sprint start; this example draws on a successful collaboration with the German Sports University Cologne, Germany and the Cardiff School of Sport, Cardiff Met, UK. The final theme, Environmental Interaction, investigates the use of artificial turf in soccer and rugby. I will discuss my work as a Research Officer on the FIFA, IRB, and Cardiff School of Sport project. This research employed an interdisciplinary approach to address the question of perception (psychology) and performance (biomechanics) on the introduction of artificial turf. Finally, I will draw some global conclusions regarding my research experience to date and will present perspectives for the future

Kinematic and kinetic analyses of human movement with respect to health, injury prevention and rehabilitation aspects

Die Arbeit gibt Einblicke in des Spektrum der Möglichkeiten der Sportbiomechanik zum einem anhand eines Methodenvergleichs, in dem die Problematik von der Vergleichbarkeit verschiedener Modellierungsmethoden behandelt wird, und zum anderen anhand eines anwendungsorientierten Teils. Realisiert wird dieser Teil durch 3 Studien zu Gelenkbelastung bei Kniebeugevariationen sowie zu Gelenkbelastung von adipösen Kindern und zu Effekte von verschiedenen Orthesen-konstruktionen auf die Kniestabilitä

EFFECT OF WALKING SPEED AND POLE LENGTH ON KINEMATICS AND DYNAMICS IN NORDIC WALKING

Nordic walking has become a wide established leisure sport in middle and northern Europe. Although cardiopulmonary benefits are well documented, reported load reductions on the lower extremities seem to be overestimated. The influence of Nordic walking speed on the gait parameters has not been researched sufficiently. The recommendations of the optimal length for Nordic walking poles vary and merely the effect of different lengths on the biomechanics of the technique has been studied. Thus, the aim of this study was to analyze the effects of Nordic walking speed and pole length on kinematic and dynamic parameters in 16 Nordic walking skilled subjects. An increase of walking speed causes a more dynamic walking pattern and leads to an increase of the ground reaction forces in the first part of the stance phase and a decrease in the middle part of the stance phase. Only fine and non-systematic changes in kinematics and ground reaction forces were observed when using poles with different pole lengths

EFFECTS OF A MANUAL THERAPY ON TIBIOFEMORAL JOINT FORCES IN PATIENTS WITH ACUTE ANTERIOR CRUCIATE LIGAMENT RUPTURE

The purpose of this study was to analyse the acute effects of the manual therapy RegentK on tibiofemoral joint forces and lower limb muscle forces in patients with an acute unilateral ACL rupture. Eight patients with an acute ACL rupture were recruited. Tibiofemoral joint forces and quadriceps, hamstring and gastrocnemius muscle forces were analysed during walking pre and immediately post the one time intervention using a musculoskeletal model.Results showed that tibiofemoral joint loading and muscle forces were altered in the injured compared to the uninjured limb, but no significant effect of the intervention could be shown. Joint and muscle force patterns, however, were highly individual. For future analyses the comparison with a matched-control group and the use of different methods to detect waveform-changes are recommended

COMPARISON OF TEMPORO-SPATIAL AND KINETIC PARAMETERS DURING DOWNHILL WALKING ON A TREADMILL AND A RAMP CONSTRUCTION

Inclined treadmills or static ramp constructions can be used to investigate downhill gait in a standardised laboratory condition. However, it is not clear how the different systems affect the gait pattern during downhill walking. Therefore temporo-spatial (Qualisys) and kinetic data (loadsol®) of 13 healthy participants walking with a given speed (1.1 m/s) downhill with a -6° decline on a treadmill and a ramp system were analysed. On the treadmill participants walked with 8% shorter steps and shorter contact times, while they increased step frequency by 6%. Peak resultant forces remained similar compared to walking on a ramp construction. These alterations might be due to mechanical and psychological effects and have to be considered when conducting and analysing research that focuses on downhill gait

THE USE OF THE GRADUAL YIELDING MECHANISM DURING DOWNHILL WALKING IN TRANSFEMORAL AMPUTEE GAIT – A CASE STUDY

To facilitate downhill walking in transfemoral amputees, some prostheses contain knee joints that have a yielding mechanism. The aim of this case study was to investigate 1) at which gradient unilateral transfemoral (UTF) amputees first utilised the yielding mechanism, 2) whether this mechanism is linked to altered spatio-temporal parameters and 3) if the switch occurs at a different gradient when the prosthetic ankle component is altered. Two UTF amputees walked at different slopes (0° to -15°) with an articulating and a rigid prosthetic ankle component. Results showed that the gradient at which the UTFs first used the yielding mechanism is highly individual (UTF1: -6°; UTF2: -12°). UTF2 showed with the switch a decreased speed, step & stride length. The use of an articulating compared to a rigid ankle component did not influence the yielding pattern

EFFECTS OF SUPPLEMENTARY MATS ON GROUND REACTION FORCES AND NEUROMUSCULAR PRE-ACTIVATION IN GYMNASTICS LANDINGS

The purpose of this study was to analyse the effects of supplementary mats on ground reaction forces (GRF) and neuromuscular activation of selected leg muscles during gymnastics landings. Participants (n=10) performed landings from 1 m and 2 m height onto a landing mat and landing mat plus a soft supplementary mat. EMG of lower extremity muscles and ground reaction forces were measured. Results showed a decrease between 15% and 40% of the peak GRF and the peak rate of force development (RFD), respectively, when using supplementary mats. While the duration of pre-activation remained unchanged, the amount of pre-activation was reduced when landing on supplementary mats. From a biomechanical point of view supplementary mats can be recommended in gymnastics landings

ASSESSMENT OF KINEMATIC CMJ DATA USING A DEEP LEARNING ALGORITHM-BASED MARKERLESS MOTION CAPTURE SYSTEM

The purpose of this study was to compare the performance of a 2D video-based markerless motion capture system to a conventional marker-based approach during a counter movement jump (CMJ). Twenty-three healthy participants performed CMJ while data were collected simultaneously via a marker-based (Oqus) and a 2D video-based motion capture system (Miqus, both: Qualisys AB, Gothenburg, Sweden). The 2D video data was further processed using Theia3D (Theia Markerless Inc.), both sets of data were analysed concurrently in Visual3D (C-motion, Inc). Excellent agreement between systems with ICCs \u3e0.988 exists for Jump height (mean average error of 0.35 cm) and ankle and knee sagittal plane angles (RMS differences \u3c 5°). The hip joint showed highe

KNEE JOINT FORCES IN CYCLING AT TWO WORKLOADS WITH CIRCULAR AND NON-CIRCULAR CHAINRINGS

The purpose of this study was to investigate the knee structure forces at two power outputs with circular and non-circular chainrings. 14 male cyclists pedalled using three different chainrings with a cadence of 90 rpm at 180 W and 300 W. Kinematics (Vicon) and kinetics (Powertec) were recorded. The knee structure forces were calculated using a 2D knee model. The tangential pedal forces were higher in the oval chainring conditions in both workloads. No differences were observed for the knee forces. The higher workload lead to significantly higher pedal and knee forces in all chainring conditions. Oval chainrings do not affect knee joint forces. Knee joint loading is highly affected by the work load, independently from the chainring systems used. The recommendation for using non-circular chainrings has not to be based on knee joint loading aspects

VALIDATION OF AN IMU-SYSTEM (GAIT-UP) TO IDENTIFY GAIT PARAMETERS IN NORMAL AND INDUCED LIMPING WALKING CONDITIONS

The purpose of this study was to investigate an IMU system (GaitUp) with respect to validity in normal and induced impaired walking by comparing with a state-of-the-art 3D motion capture system. The gait of nine participants was analysed collecting data simultaneously with the GaitUp (Physiolog) placed at each foot and an eight camera motion capture system (Vicon) at 200 Hz each. Participants walked in normal and induced limping (elevation of one shoe) conditions at three walking speeds. For all conditions the two systems yielded similar results regarding the standard gait parameters (gait cycle time, stride length, stride frequency and gait velocity) according to absolute differences and correlation coefficients. GaitUp gathers fairly valid and reliable data in normal and limping walking in a range of walking speed between 0.9 and 2.0 m/s