Peter Brueggemann

Footfall patterns during barefoot running on harder and softer surfaces

It has been suggested that the development of a thick, soft midsole of running shoes over the past 30 years has been primarily responsible for the majority of runners adopting a rearfoot or heel-toe footfall pattern thus deviating from a more ‘natural’ forefoot pattern. The purpose of this study was to determine the freely chosen footfall pattern when running barefoot on a harder versus a softer surface. Forty habitual rearfoot runners performed two running conditions: barefoot over a harder surface and barefoot over a softer surface. Three-dimensional motion analysis and ground reaction force data were collected to measure the ankle angle, vertical impact peak and strike index. The kinematic and kinetic parameters were used to confirm the footfall pattern in each condition. Only 20% per cent of the participants ran with a midfoot or forefoot pattern on the soft surface whereas 65% of the participants ran with a midfoot or forefoot pattern when running on the hard surface. Out of the 80% of participants that maintained a rearfoot pattern on the soft surface, 43% of these participants ran with a midfoot or forefoot pattern on the hard surface. These results suggest that, while running barefoot, the hardness of the running surface may be a significant factor causing an alteration in a runners footfall pattern.

Effect of rocker shoe design features on forefoot plantar pressures in people with and without diabetes

BACKGROUND There is no consensus on the precise rocker shoe outsole design that will optimally reduce plantar pressure in people with diabetes. This study aimed to understand how peak plantar pressure is influenced by systematically varying three design features which characterise a curved rocker shoe: apex angle, apex position and rocker angle. METHODS A total of 12 different rocker shoe designs, spanning a range of each of the three design features, were tested in 24 people with diabetes and 24 healthy participants. Each subject also wore a flexible control shoe. Peak plantar pressure, in four anatomical regions, was recorded for each of the 13 shoes during walking at a controlled speed. FINDINGS There were a number of significant main effects for each of the three design features, however, the precise effect of each feature varied between the different regions. The results demonstrated maximum pressure reduction in the 2nd-4th metatarsal regions (39%) but that lower rocker angles (<20°) and anterior apex positions (>60% shoe length) should be avoided for this region. The effect of apex angle was most pronounced in the 1st metatarsophalangeal region with a clear decrease in pressure as the apex angle was increased to 100°. INTERPRETATION We suggest that an outsole design with a 95° apex angle, apex position at 60% of shoe length and 20° rocker angle may achieve an optimal balance for offloading different regions of the forefoot. However, future studies incorporating additional design feature combinations, on high risk patients, are required to make definitive recommendations.

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

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.

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.

Neuromuscular response to perturbation of the habitual joint motion path in running

Only a few badminton studies using three-dimensional motion analysis research during game-like situations exist because of the complexity involved in carrying out experimental research. Based on our findings, only slightly modification of outsole stiffness in a badminton shoe has an impact on changes in lower extremity kinematics during various badminton tasks. However, further studies on female, subelite or amateur players would also be evaluated to ascertain whether stiffening the outsole of a badminton shoe has an impact on performance and comfort. Changes in forefoot kinematics due to the modification of outsole stiffness may alter kinematics of adjacent joints of the lower extremity and also contribute to changes in movement strategies and agility performance during badminton movements. Therefore, optimal forefoot bending stiffness executed by different kinds of shoe construction for enhanced athlete agility and shoe comfort performance should be one key direction.

The impact of current footwear technology on free moment application in running

anecdote and common practice. Although there were no other significant main effects of shoe condition, it is worth noting that main effects of shoe condition for COP-AP approached significance (F D 3.91, p D 0.07, ƞp D 0.23) with the unshod condition showing greater COP excursion than the shod condition. With this pattern emerging in both deadlift and back squat studies (Whitting et al., 2016), it may indicate that the hypothesis that regular training shoes provide less stability during the conventional deadlift is incorrect within the current parameters of COP testing (Lafond et al., 2004). It is also important to note that Whitting et al. (2016) mentioned a difference in perception of stability between shoe conditions and that motor control strategies to manipulate the load lifted may be a factor in determining the limits of COP excursion. Nonetheless, given the findings of this preliminary investigation it would appear that unshod conditions may not have a substantial effect on kinetic parameters during the conventional deadlift.

Calcaneal movement measured by skin versus shoe-mounted markers

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Effects of midsole density distribution on kinematics and kinetics in running

During the first 2.5-minute bout, T2 values increased significantly for all of the analysed muscles. The experimental intervention with lateral posting significantly altered the muscle metabolism for the TP (120%), the EDL (72%), the SO (50%), the TA (49%), the GL (29%), and not significantly for the GM (11%) and the PER (7%). However, there were no significant changes in the T2 values in the two following bouts in all muscles. The intervention affected knee joint fontal plane movement and increased peak abduction angle from 3.8 § 4.0 to 5.1 § 4.3 (p < 0.05). In the transverse plane peak internal tibia rotation changed from 6.0 § 3.9 to 7.5 § 5.0 . Rearfoot eversion range of motion increased in lp-shoe from 8 to 14 (p < 0.01).

Effects of midsole design on extrinsic foot muscles metabolism during running

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