Shock absorption characteristics of running shoes

Abstract

The change in shock absorption properties of running shoes was evaluated as a function of miles run. Different models of running shoes encompassing a wide range in retail price were obtained and mechanically tested to simulate the repeated heel strikes of running. The energy absorbed by the shoes was determined from the area under the load deformation curve at the equivalent of 0, 5, 10, 25, 50, 75, 100, 125, 150, 200, 250, 300, and 500 miles of running. Shoes were also tested at similar intervals after having been worn by volunteers during normal training. An approximate 33% difference in the initial shock absorption was observed in the different shoe models. In general, the shoes retained approximately 75% of their initial shock absorption capability after 50 miles of simulated running, and approximately 67% after 100 to 150 miles. Between 250 and 500 miles the shoes retained less than 60% of their initial shock absorption capacity. No differences in shock absorption characteristics were apparent based upon either shoe price or the manufacturer model. The results of shoes tested by the volunteer runners also showed a marked reduction in shock absorption with mileage. The loss, however, was not as great as in the machine-simulated running, with approximately 70% of initial shock absorption retained at 500 miles.

Effect of the shoe on plantar foot pressures

“…However, the pressure distribution on a rubber-soled shoe during the stance phase was similar to that of the leather sole. After 500 miles, a sports shoe loses 50 percent of its shock-absorption capacity (Cook et al 1985) and the rubber shoes used by our volunteers were at least 3 months old.…”

Evaluation of Injury Rates During Implementation of the Fort Drum Running Shoe Injury Prevention Program

“…Cook et al (21) tested 25 models of shoes for initial shock absorbency and changes in shock absorbency. A prosthetic foot and mechanical piston was used to apply forces equivalent to those of running.…”

Transverse rotation and longitudinal translation during prosthetic gait-A literature review

“…Because its absorbency depends on its thickness [17], wear because of repetitive impact may compromise the absorbing characteristics by triggering degenerative changes. However, additional shock absorbers including shock absorbing shoes and shoe inserts can be worn, which help to prevent or compensate for excessive wear of anatomical shock absorbers [15,18,19]. Also, the foot can be considered a shock absorber as a whole because of the relative displacement of the bones as a result of the elastic properties of tendons, ligaments, and muscles, which allow the foot to deform and by doing so to store and release energy [20].…”