Pukkelpop Forum Forum

Labi1995 · Clubopener Geregistreerd op: 19 Jan 2019 Berichten: 322

Clarke et. al (1983) measured the height of the vertical impact peak, the time it took to reach the vertical impact peak (which gives info about how fast the impact force was applied), the height of the active peak, as well as a few other gait variables. Nike Air Max 95 Hombre Keeping in mind that the shoes being compared were at opposite extremes of the firmness spectrum, the results were quite interesting. First, and somewhat surprisingly, they found no significant difference in the height of the impact peak between the two shoes. In other Adidas Superstar Femme words, the magnitude of the impact force was the same on average whether a runner was wearing a soft shoe or a firm shoe. The time it took to reach the impact peak was found to differ, with the softer shoe delaying the impact peak by about 4 milliseconds on average (this means that the softer shoe tended to slow the application of the impact force, which is probably a good thing). Third, they found that the active peak (they refer to it as the propulsive peak) was significantly higher on average in the softer shoe.
In summary, just looking at the average results, softer, cushier shoes do not appear to reduce the impact force, but they do slow down the rate at which the force is applied to the body (much as a boxing glove would slow the rate at which impact is applied to your hand if you punched a brick wall). Softer shoes also result Nike Air Max 90 Femme in higher forces at mid-stance – the authors suspect this might be related to greater heel penetration into the midsole during stance, allowing the calf muscles to exert greater propulsive force under the forefoot on pushoff (if the heel sinks into the misdole under pressure, it is effectively decreasing the heel-forefoot drop).These results, particularly regarding impact force, seem somewhat counterintuitive – runners generally believe that greater cushioning will reduce the magnitude of the impact force, and heavy runners are often directed to maximally cushioned shoes for this very reason. But, this ignores the fact that our body is pretty darned intelligent, and our legs adapt their stiffness to the conditions underfoot (read this post for more on leg stiffness in running). Thus, when running in a firm shoe, our knees tend Nike Air Vapormax Dames to flex more than they do when we run in a soft shoe – by changing properties of the midsole all we do is shift cushioning from one place to another (underfoot to say the knee joint), and the magnitude of the impact force stays the same.What’s really interesting about this study Nike Air Span 2 Dames is when you look at the individual results, which are quite variable. Two individuals exhibited no impact peak at all, and their results thus were not included in the impact comparisons (the authors speculated that they were midfoot strikers). Here are the results the individuals (forces are measured in units of body weight)When you look at these results at the level of the individual, it becomes clear that responses are somewhat variable. In particular, if you look at the results for impact force peak in subjects 4 and 5, they exhibit completely opposite Nike Air Max 270 Womens responses to the two shoes. Subject 4 impacts considerable harder in the hard shoe, but subject 5 impacts considerably harder in the soft shoe. So, although the mean impact response between the two shoes was not significantly different, suggesting that midsole hardness need not Adidas Ultra Boost Femme be a consideration when it comes to managing impact force, for these two individuals it matters a great deal. What’s more, if we assume that lessening impact force is a good thing (this point is debatable as impact can stimulate bone growth, and we have no idea what threshold limits for impact might be problematic for any given individual), these two runners would require completely different types of shoes! Going even further along this line of reasoning, if our goal was to provide a shoe for these runners to reduce impact, the conventional wisdom is that Nike Air Span 2 Herren more cushioning is the way to go – but, that would be the wrong answer for 50% of the runners examined here who had higher impact peaks in the softer shoes. This is what gets lost when looking at mean responses – they don’t tell you what is best on an individual level.You can Nike Air Max 2017 Femme see the same type of thing when you scan the other columns. Soft shoes generally do seem to delay impact peak, but not in 100% of cases, and in some individuals the difference is very small between the two shoes. Soft shoes seem to result in a higher active peak, but again, sometimes the difference is quite small.