Sensory Perception of Varied Shoe Masses in Running.

BACKGROUND: Studies on the sensory perception of mass mostly focus on the hands rather than the feet. The aim of our study is to measure how accurately runners can perceive additional shoe mass in comparison to a control shoe (CS) while running, and moreover, whether there is a learning effect in the perception of mass. Indoor running shoes were categorized as a CS (283 g) and shoes with four additional masses: shoe 2 (+50 g), shoe 3 (+150 g), shoe 4 (+250 g), and shoe 5 (+315 g). METHODS: There were 22 participants in the experiment, which was divided into two sessions. In session 1, participants ran on a treadmill for 2 min with the CS and then put on one set of weighted shoes and ran for another 2 min at a preferred velocity. A binary question was used after the pair test. This process was repeated for all the shoes to compare them with the CS. RESULTS: Based on our statistical analysis (mixed effect logistic regression), the independent variable (ie, mass) did have a significant effect on perceived mass (F4,193 = 10.66, P < .0001), whereas repeating the task did not show a significant learning effect (F1,193 = 1.06, P = .30). CONCLUSIONS: An increase of 150 g is the just-noticeable difference among other weighted shoes and the Weber fraction is equal to 0.53 (150:283 g). Learning effect did not improve by repeating the task in two sessions in the same day. This study facilitates our understanding about sense of force and enhances multibody simulation in running.

Evaluating the Effect of Shoes with Varying Mass on Vertical Ground Reaction Force Parameters in Short-Term Running.

Past investigations have revealed that running shoes affect ground reaction force parameters. However, these studies are unclear as to whether these changes, which occur while running in different shoe types of differing masses, are the result of the structural design or the mass of the shoe. The main aim of this study is to evaluate the effect of shoe mass on vertical ground reaction force parameters: active peak and impulse. Methods. 21 male runners (24.52 years old (± 3.09) and 77.13kg (± 7.9)) participated in the experiment. A baseline shoe (BS) = 283g and four weighted shoes (shoe 2 = 333g, shoe 3 = 433g, shoe 4 = 533g and shoe 5 = 598g) were compared for 8 minutes of running on the instrumented treadmill. Each shoe was compared in a repeated measurement with the BS. Results showed that active peaks and impulses differed significantly (p < .05) between the BS and weighted shoes, except for shoe 2. From the threshold of 433g (shoe 3, which is 1.5 times heavier than the BS), we observed a significant increase in the vertical ground reaction force peak (1.86%) and impulse (1.84%). Other shoes such as shoe 4 and shoe 5, produced increasingly active peaks (N) of 2.08% N and 2.45% N compared to the BS. Increase of shoe masses in shoe 3, shoe 4, and shoe 5 resulted in an increase of impulse up to 1.84% Nm, 1.85% Nm and 2.49% Nm compared to the BS. Our determination of the shoe masses influencing these kinetic parameters may be a step towards reducing running-related injuries that result from accumulated microtrauma.