Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.

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Foot strike patterns and collision forces in habitually barefoot versus shod runners

Synopsis During the last decade, there has been a growing body of literature suggesting that proximal factors may play a contributory role with respect to knee injuries. A review of the biomechanical and clinical studies in this area indicates that impaired muscular control of the hip, pelvis, and trunk can affect tibiofemoral and patellofemoral joint kinematics and kinetics in multiple planes. In particular, there is evidence that motion impairments at the hip may underlie injuries such as anterior cruciate ligament tears, iliotibial band syndrome, and patellofemoral joint pain. In addition, the literature suggests that females may be more disposed to proximal influences than males. Based on the evidence presented as part of this clinical commentary, it can be argued that interventions which address proximal impairments may be beneficial for patients who present with various knee conditions. More specifically, a biomechanical argument can be made for the incorporation of pelvis and trunk stability, as we...

https://www.jospt.org/doi/pdf/10.2519/jospt.2010.3337

The Influence of Abnormal Hip Mechanics on Knee Injury: A Biomechanical Perspective

Foundations of Clinical Research: Applications to Practice, 2nd Edition, Leslie Gross Portney, Mary P. Watkins. Prentice Hall, Upper Saddle River, NJ (2000), 752 pages. $60

DAOUD, A. I., G. J. GEISSLER, F. WANG, J. SARETSKY, Y. A. DAOUD, and D. E. LIEBERMAN. Foot Strike and Injury Rates in Endurance Runners: A Retrospective Study. Med. Sci. Sports Exerc., Vol. 44, No. 7, pp. 1325‐1334, 2012. Purpose: This retrospective study tests if runners who habitually forefoot strike have different rates of injury than runners who habitually rearfoot strike. Methods: We measured the strike characteristics of middle- and long-distance runners from a collegiate cross-country team and quantified their history of injury, including the incidence and rate of specific injuries, the severity of each injury, and the rate of mild, moderate, and severe injuries per mile run. Results: Of the 52 runners studied, 36 (69%) primarily used a rearfoot strike and 16 (31%) primarily used a forefoot strike. Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike. Traumatic injury rates were not significantly different between the two groups. A generalized linear model showed that strike type, sex, race distance, and average miles per week each correlate significantly (P G 0.01) with repetitive injury rates. Conclusions: Competitive cross-country runners on a college team incur high injury rates, but runners who habitually rearfoot strike have significantly higher rates of repetitive stress injury than those who mostly forefoot strike. This study does not test the causal bases for this general difference. One hypothesis, which requires further research, is that the absence of a marked impact peak in the ground reaction force during a forefoot strike

Foot strike and injury rates in endurance runners: a retrospective study.

Orthopedic physical assessment

Objective:To compare selected structural and biomechanical factors between female runners with a history of plantar fasciitis and healthy control subjects.Design:Cross-sectional.Setting:University of Delaware Motion Analysis Laboratory, Newark, Delaware; and University of Massachusetts Biomechanics

Michael B. Pohl

Papers

Biomechanical and anatomic factors associated with a history of plantar fasciitis in female runners.

Biomechanical predictors of retrospective tibial stress fractures in runners

Proximal and Distal Kinematics in Female Runners with Patellofemoral Pain

Forefoot, rearfoot and shank coupling: effect of variations in speed and mode of gait.

Can the reliability of three-dimensional running kinematics be improved using functional joint methodology?