Katina Mira Fischer

Tibial rotation in running: Does rearfoot adduction matter?

OBJECTIVE To quantify the magnitude of global rearfoot motion, in particular, rearfoot adduction and to investigate its relationship to tibial rotation. DESIGN One hundred and four participants ran barefoot on an Ethylene Vinyl Acetate (EVA) foam. Global range of motion values for the shank, rearfoot and medial metatarsal segment as well as foot motion within the transverse plane were determined using an optoelectric motion capture system. Relationships between parameters were assessed using partial correlation analysis. RESULTS Global rearfoot adduction amounts to 6.1° (±2.7). Furthermore global rearfoot adduction and rearfoot eversion were significantly related to internal tibial rotation (partial correlation: r=0.37, p<0.001 and r=-0.24, p=0.015, respectively). Furthermore, a strong relationship between rearfoot adduction and transverse within foot motion (r=-0.65, p<0.001) was found. CONCLUSION Next to rearfoot eversion, rearfoot adduction may be also important to the understanding of ankle joint coupling. Controlling rearfoot adduction and transverse within foot motion may be a mechanism to control excessive tibial rotation.

Free moment patterns in distance running

Steffen Willwacher*, Katina Fischer, Joseph Hamill, Eric Rohr and Peter Brueggemann German Sports University Cologne, Institute for Biomechanics and Orthopaedics, Am Sportpark M€ ungersdorf 6, K€ oln, 50933 Germany; University of Massachusetts, Kinesiology, 30 Eastman Lane, Amherst, 01003 United States; Brooks Sports, Inc., Biomechanics Laboratory, 19910 North Creek Parkway, Bothell, 98011-8215 United States

Kinetics of cross-slope running

The purpose of the present study was to identify kinetic responses to running on mediolaterally elevated (cross-sloped) running surfaces. Ground reaction forces (GRFs), GRF lever arms and joint moment characteristics of 19 male runners were analyzed when running at 3.5m/s on a custom-made, tiltable runway. Tilt angles of 3° and 6° for medial and lateral elevation were analyzed using a 10 camera Vicon Nexus system and a force platform. The point of force application of the GRF showed a systematic shift in the order of 1-1.5cm to either the lateral or medial aspect of the foot for lateral or medial inclinations, respectively. Consequently, the strongest significant effects of tilt orientation and level on joint kinetics and ground reaction force lever arms were identified at the ankle, knee and hip joint in the frontal plane of movement. External eversion moments at the ankle were significantly increased by 35% for 6° of lateral elevation and decreased by 16% for 6° of medial elevation. Altering the cross-slope of the running surface changed the pattern of ankle joint moments in the transversal plane. Effect sizes were on average larger for laterally elevated conditions, indicating a higher sensitivity of kinetic parameters to this kind of surface tilt. These alterations in joint kinetics should be considered in the choice of the running environment, especially for specific risk groups, like runners in rehabilitation processes.

The free moment in running and its relation to joint loading and injury risk

The purpose of this study was to explore the relationship between free moment (FM) characteristics, joint mechanics and injury risk, in order to evaluate the potential of the FM as a variable for runner classification into functional groups with similar footwear demands. Lower extremity joint mechanics, ground reaction forces and the FM of 222 male and female injury free runners were analysed using an optoelectric motion capture system and a force plate while running at 3.5 m/s. During a follow-up period of 6 months, runners were reporting any running-related injuries to an experienced orthopaedist. Different FM patterns could be extracted using functional principal component analysis (FPCA). The first two eigenfunctions derived from FPCA were able to predict about 87% of the variance in the data-set and could be related to the two main functions of FM application in straight running -- transversal plane whole body oscillation control and compensation of insufficient transversal moment cancellation. FM patterns differed with respect to lower extremity joint moments and joint kinematics, mostly in the transversal and frontal plane of motion. Runners suffering from patellofemoral pain syndrome showed FM patterns with distinct external rotation components and differed from their matching controls, even though the number of runners, who suffered from injuries were too low to allow valid inferences. In conclusion, it seems that the FM could be useful in the classification of runners into functional groups as it possesses a considerable inter-subject variability, a relationship to the mechanical demands put on lower extremity joints and potentially to injury risk, while being comparably easy to measure.

The effect of shoes, surface conditions and sex on leg geometry at touchdown in habitually shod runners

Leg geometry at touchdown has a critical effect on joint loading in the initial contact phase in running. The purpose of this study was to systematically investigate the effects of footwear, surface conditions and sex on the kinematic striking configuration of the lower extremity when running at a constant speed (3.5 m/s). Three-dimensional touchdown kinematics were captured from 20 male and 19 female participants when running barefoot and with a neutral running shoe on four different surfaces. On harder surfaces and when running barefoot, subjects tended to land with a more plantarflexed foot position and ankle angle as well as a more vertical shank alignment. Different adaptation strategies to running surface stiffness were observed between barefoot and shod conditions. It seems that touchdown behaviour is adapted to compensate for the force distributing and energy absorption potentials of distinct surface x shoe combinations. If the combined compliance of the shoe plus surface combination exceeds a certain level, touchdown kinematics seem to be adapted to improve joint stability during early stance. Sex effects were identified mainly in shank and thigh frontal plane orientation and knee flexion angle.

Free moment patterns, transversal plane joint loading and injury risk in running

The free moment (FM) of ground reaction is applied by runners to the ground in order to control whole body angular momentum in the transversal plane of movement. The FM is a dominant component of l...

The potential of foot mounted 3D accelerometers to predict lower extremity loading in running

The results show that the tested rocker shoes influence the GRF alignment angle. The lowest average GRF alignment angle was found for rocker B which can be related to the different rocker position of the rocker B that is placed in almost mid-length of the shoe outsole (52%). Although it has been previously well demonstrated that the rocker outsoles are the most effective shoe modification to decrease plantar pressures, they can increase shear stresses compared to barefoot. Our results from one subject indicate that the shoe design influences the GRF alignment and rocking angles. Further studies with a larger participant number are needed to investigate the effect of the rocker outsole design on the GRF alignment and rocking angles between individuals.

Calcaneal adduction in slow running : three case studies using intracortical pins.

The aim of this study was to use bone-anchored markers to determine the bone movement of calcaneal adduction, eversion and tibial rotation in a global coordinate system and to describe the relationship of calcaneal adduction to tibial rotation. Furthermore, the amount of overall intra-foot motion in the transverse plane (metatarsal I relative to calcaneus) and its relationship to calcaneal adduction were quantified. Three male participants were assessed during slow running. A 10-camera motion analysis system was used for kinematic data capture of global bone orientations in 3D space for all bones of the foot and ankle complex. For the description of intrinsic articulations within the foot, the skeletal motion relative to the adjacent proximal segment in the transverse plane was calculated. Furthermore, the time of occurrence of maximum values was determined. The findings showed that calcaneal adduction of all participants amounted to 7.8 ± 4.8°, which exceeded the magnitude of calcaneal eversion (4.7 ± 3.1°). Although the inter-participant variability was high, considerable overall intra-foot motion in the transverse plane of the metatarsal I relative to the calcaneus was found to be 4.7 ± 4.6° and could be qualitatively related to calcaneal adduction. The present data provide evidence that next to calcaneal eversion, calcaneal adduction seems related to tibial rotation. Furthermore, overall intra-foot motion in the transverse plane seems related to calcaneal adduction. Controlling calcaneal adduction and overall intra-foot motion in the transverse plane may be a mechanism to control excessive tibial rotation in runners who suffer from overuse knee injuries. These findings could be used to provide an additional approach for future motion-control footwear design to control rearfoot adduction or overall within-foot motion.

The calcaneus adducts more than the shoe's heel during running

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 studys 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.

The coupling between calcaneal adduction and tibial rotation: a framework for a novel motion control footwear design

touchdown and a greater initial ankle plantar flexion range of motion until the foot is flat. Indeed, Gerritsen et al. (1995) supposed that the eccentric contraction of tibialis anterior muscle following a rearfoot landing acts on the absorption of impact energy. A forward progression of strike index does not automatically lead to a decrease of LR and it seems that extreme FATD in forefoot or rearfoot landing are needed in order to reduce LR.