Shock attenuation of the impact peak and overpronation are both considered important in running shoe design. A number of investigations indicate that both of these factors are related to various running injuries. These indications are mostly empirical or based on statistics and often show a lack of arguments to relate external measurements to internal loading of joints or muscles. The purpose of this paper is to present some relationships between impact peak, pronation, and forces at the subtalar joint and on muscles (which are in tension in pronation) during touchdown in rearfoot running. The calculations show that the material properties of the shoe sole (altered from Shore A20 to A50) largely influence the rearfoot movements during touchdown (increase in pronation velocity from 7 to 25 rad/s) and increase to some extent the muscle forces on the medial side (600 to 850 N) of the subtalar joint. In comparison, the impact peak (1550 to 1600 N) and the ankle joint forces (2500 to 2700 N) change very little. Hence, running shoe design should be focused more on the control of the rearfoot movement during touchdown and less on pure shock attenuation.
Alex Stacoff, Jachen Denoth, Xaver Kaelin, and Edgar Stuessi
Ryuji Kawamoto, Yusuke Ishige, Koji Watarai, and Senshi Fukashiro
The purpose of this study was to test quantitatively the hypothesis that, as runners run along a more sharply curved track, greater torsional moments act on their tibiae. Six male participants were asked to run along a straight track and along counterclockwise curved tracks with turn radii of 15 m (gentle) and 5 m (sharp) at 3.5 m s–1. Data were collected using two high-speed cameras and force platforms. Each participant’s left (corresponding to the inside of the curves) foot and tibia were modeled as a system of coupled rigid bodies. For analysis, net axial moments acting on both ends of the tibia were calculated using free-body analysis. The torsional moment acting on the tibia was determined from the quasi-equilibrium balance of the tibial axial moments based on the assumption that the rate of change of the angular momentum about the tibial axis was negligible. The results showed that the torsional moments, which were in the direction of external rotational loading of the proximal tibiae, increased as the track curvature became sharper. Furthermore, the mean value of the maximum torsional moments, while running on a sharply curved track (28.5 Nm), was significantly higher than the values obtained while running on a straight track (11.0 Nm, p < .01) and on a gently curved track (12.2 Nm, p < .01). In conclusion, the present study has quantitatively confirmed that as runners run along a more sharply curved track, greater torsional moments act on their tibiae. The findings imply that athletes prone to tibial running injuries such as stress fractures should avoid repetitive running on sharply curved paths.
Jessica G. Hunter, Gina L. Garcia, Sushant M. Ranadive, Jae Kun Shim, and Ross H. Miller
Running is a popular activity for fitness and health, 1 , 2 but running-related injury rates are high in all levels of runners. 3 – 7 Running injuries create a barrier to continued activity especially as runners age, 7 which limits injured runners from reaping the health benefits of regular
Tona Hetzler, Amy E. Smith, and Doug Rempe
Peter Francis, Cassie Oddy, and Mark I. Johnson
In a 27-year-old female triathlete, magnetic resonance imaging revealed mild thickening and edema at the calcaneal insertion of the plantar fascia, in keeping with a degree of plantar fasciitis. After 6 weeks of conservative treatment failed to elicit a return to sport, the patient engaged in six sessions of barefoot running (15–30 min) on a soft grass surface, without further conservative treatment. After two sessions of barefoot running, the patient was asymptomatic before, during, and after running. This outcome was maintained at the 6-week follow-up period. This is the first case report to use barefoot running as a treatment strategy for chronic heel pain. Barefoot running has the potential to reduce the load on the plantar fascia and warrants further investigation using a case series.
Kevin S. Masters and Michael J. Lambert
The psychology of marathon running was studied by employing the cognitive strategies of association and dissociation (Morgan, 1978; Morgan & Pollock, 1977). Two shortcomings in the current literature were cited. These included the failure to study marathon runners in an actual race and the absence of an acceptable theory to explain the use of these strategies. In the present research, runners participating in a marathon were utilized and measures of dissociation, association, performance time, injury, and reasons for running a marathon were taken. The results indicated that motivations may have accounted for the use of cognitive strategies and that injury was not related to dissociation, as previously hypothesized. Additionally, runners overwhelmingly preferred to associate. A new theory regarding the use of these strategies was offered.
Janice K. Loudon and Marcie Swift
. BW = bodyweight; VGRF = vertical ground reaction force; IP = impact peak; LR = loading rate. The study of running injury prevention has focused on a variety of biomechanical issues including the management of high-impact loading. 6 Running shoe selection has been investigated for decades as a
Shannon L. Mihalko, Phillip Cox, Edward Ip, David F. Martin, Paul DeVita, Monica Love, Santiago Saldana, D. Wayne Cannon, Rebecca E. Fellin, Joseph F. Seay, and Stephen P. Messier
from a variety of physical impairments, as well as an important mediator of QOL. Overall, these studies highlight the need for prospective observation of overuse running injuries to understand the impact of running-related injuries on QOL. A better understanding of potential mechanisms underlying this
Kevin Deschamps, Giovanni Matricali, Maarten Eerdekens, Sander Wuite, Alberto Leardini, and Filip Staes
In foot mechanics, bone structure and joint kinematics have long been considered risk factors for foot and lower-limb running injuries, 1 , 2 but the role of foot kinetics has been largely overlooked. The foot mechanics result from a complex interaction between its many bony segments and joints
Alex Stacoff, Xaver Kaelin, Edgar Stuessi, and Bernhard Segesser
In the research of running shoes, excessive pronation is often related to various running injuries. Anatomically, pronation is a movement that occurs in more than one joint. Previous investigations that evaluated the pronation in running studied the movements of the lower leg and the rearfoot only. However, pronation could also be influenced by the movement of the forefoot and therefore depend on the torsional stiffness of the foot and of the shoe sole. This study investigated the relationship between the torsion and the pronation in running with a rearfoot touchdown and with a forefoot touchdown. The results show that, compared to running barefoot, running with a shoe decreases torsion and thereby increases pronation significantly (p < 0.01) for the forefoot and rearfoot touchdown conditions. Thus the reduction of torsional movement due to stiff shoe soles could well be a reason for running injuries caused by excessive pronation. It is concluded that modern running shoes could be designed to allow a certain torsional movement of the foot.