superior cushioning properties of running shoes to decrease running-related injuries, especially in high-speed running. The purpose of this study was to investigate the influence of running speed and midsole types on foot loading for heel–toe running. Our primary hypothesis was that faster speeds would not
Piaolin Peng, Shaolan Ding, Zhikang Wang, Yifan Zhang, and Jiahao Pan
Alexander Bahlsen and Benno M. Nigg
Impact forces analysis in heel-toe running is often used to examine the reduction of impact forces for different running shoes and/or running techniques. Body mass is reported to be a dominant predictor of vertical impact force peaks. However, it is not evident whether this finding is only true for the real body mass or whether it is also true for additional masses attached to the body (e.g., running with additional weight or heavy shoes). The purpose of this study was to determine the effect of additional mass on vertical impact force peaks and running style. Nineteen subjects (9 males, 10 females) with a mean mass of 74.2 kg/56.2 kg (SD = 10.0 kg and 6.0 kg) volunteered to participate in this study. Additional masses were attached to the shoe (.05 and .1 kg), the tibia (.2, .4, .6 kg), and the hip (5.9 and 10.7 kg). Force plate measurements and high-speed film data were analyzed. In this study the vertical impact force peaks, Fzi, were not affected by additional masses, the vertical active force peaks, Fza, were only affected by additional masses greater than 6 kg, and the movement was only different in the knee angle at touchdown, ϵ0, for additional masses greater than .6 kg. The results of this study did not support findings reported earlier in the literature that body mass is a dominant predictor of external vertical impact force peaks.
Benno M. Nigg and H. Alexander Bahlsen
The purpose of this study was to determine the influence of lateral heel flare on pronation, external impact forces, and takeoff supination for different midsole constructions. Data were collected using force platforms and high-speed film cameras. Fourteen male subjects participated in the study, running heel-toe at a speed of 4 m/s. The analysis of kinetic and kinematic variables showed that changes in lateral heel flare of 16°, 0°, and a rounded heel can be used to influence initial pronation during heel-toe running. It could be shown that changes in lateral heel flare do not have a relevant influence on changes in total and/or maximal pronation. Changes in lateral heel flare do have an effect on vertical impact force peaks if the midsole is relatively hard but not if the midsole is relatively soft. Based on the present study, a running shoe with a relatively hard midsole material and a neutral flare would have low initial pronation values and low vertical impact force peaks.
Benno M. Nigg, Gerald K. Cole, and Gert-Peter Brüggemann
Impact forces have been speculated to be associated with the development of musculoskeletal injuries. However, several findings indicate that the concepts of “impact forces” and the paradigms of their “cushioning” may not be well understood in relation to the etiology of running injuries and that complex mechanisms may be responsible for injury development during running. The purposes of this paper are (a) to review impact mechanics during locomotion, (b) to review injuries and changes of biological tissue due to impact loading, and (c) to synthesize the mechanical and biological findings. In addition, directions for future research are discussed. Future research should address the development of noninvasive techniques to assess changes in the morphology and biochemistry of bone, cartilage, tendon, and ligaments; researchers should also try to simulate impact loading during activities such as running, focusing on the interaction of the various loading parameters that determine the acceptable windows of loading for biological tissues.
Nenzi Wang and Yen-Hsiu Liu
An efficient global optimization procedure is presented by using Taguchi's design of experiments (TDE) as a means for undertaking biomechanical studies that rely on experimentations. The proposed TDE is a systematic method of fractional factorial designs for conducting experiments with many independent variables. The approach can provide a step-by-step means for predicting the results of a comparative full factorial design only with a small number of tests. In this study a three-level, four-variable heel-toe running model, and a two-level, seven-variable bicycle example were examined to show the capability and robustness of TDE. In the process of the analysis, the orthogonal array and signal-to-noise ratio analysis of TDE were used to set up the trial conditions and analyze the results. It is shown that in the heel-toe running analyses the TDE successfully predicted the optimum sets of variables with 89% fewer trials than the full factorial design. The reduction in number of trials in the bicycle example is 94%. As a result, the use of TDE analysis to replace a full factorial analysis can considerably reduce the number of trials and still provide a useful outcome in many multifactor biomechanical studies.
George Vagenas and Blaine Hoshizaki
The purpose of this study was to identify the kinematic characteristics of bilateral rearfoot asymmetry during heel–toe running under two experimental conditions: worn (broken-in) running shoes and new (standardized) running shoes. High-speed cinematography (150 fps) was used to film the lower limbs of four male runners in the frontal plane while running on a treadmill at their training pace. Six successive footfalls were analyzed for each subject and selected kinematical variables of the rearfoot function were calculated. Significant asymmetries were found in lower leg angle and Achilles tendon angle at touchdown and at maximum pronation. Total pronation and rearfoot angle were almost symmetric. The angular displacement graphs for the shank and foot revealed a distinct overall asymmetry between the lower limbs in both conditions. The mean values of the kinematical asymmetries were appreciably higher in the new shoe condition. It is proposed that the degree of these asymmetries is subject to changes due to injury, personal running style, and stability of the running shoe. Trends of bilateral dominance specific to rearfoot control in running were identified.
Allison H. Gruber, Shuqi Zhang, Jiahao Pan, and Li Li
.1097/00005768-200011000-00016 11079523 3. Nigg BM , Bahlsen HA , Luethi SM , Stokes S . The influence of running velocity and midsole hardness on external impact forces in heel-toe running . J Biomech . 1987 ; 20 ( 10 ): 951 – 959 . doi:10.1016/0021-9290(87)90324-1 3693376 10.1016/0021-9290(87)90324-1 4. Baltich J
Bastiaan Breine, Philippe Malcolm, Veerle Segers, Joeri Gerlo, Rud Derie, Todd Pataky, Edward C. Frederick, and Dirk De Clercq
.clinbiomech.2010.08.005 8. Gerritsen KG , van den Bogert AJ , Nigg BM . Direct dynamics simulation of the impact phase in heel-toe running . J Biomech . 1995 ; 28 ( 6 ): 661 – 668 . PubMed doi:10.1016/0021-9290(94)00127-P 10.1016/0021-9290(94)00127-P 7601865 9
Jessica G. Hunter, Alexander M.B. Smith, Lena M. Sciarratta, Stephen Suydam, Jae Kun Shim, and Ross H. Miller
velocity and midsole hardness on external impact forces in heel-toe-running . J Biomech . 1987 ; 20 ( 10 ): 951 – 959 . PubMed ID: 3693376 doi:10.1016/0021-9290(87)90324-1 3693376 10.1016/0021-9290(87)90324-1 10. Hunter JG , Garcia GL , Shim JK , Miller RH . Fast running does not contribute
Hin Fong Leong, Wing-Kai Lam, Wei Xuan Ng, and Pui Wah Kong
.1123/jab.11.4.395 10. Kersting UG , Bruggemann GP . Midsole material-related force control during heel-toe running . Res Sports Med . 2006 ; 14 ( 1 ): 1 – 17 . PubMed ID: 16700401 doi:10.1080/15438620500528158 10.1080/15438620500528158 16700401 11. Milani TL , Hennig EM , Lafortune MA