While the term “impact peak” can still refer to a transient that exhibits a local maximum, a local maximum is not a necessary condition for existence of an impact transient. The current study demonstrates that novice BF runners are successful at immediately reducing loading parameters when they are provided with instruction and real-time feedback on transitioning to an FFS pattern. We reported a large decrease in VALR and VILR during the BF run compared to
the shod. This is contrary to other studies that reported increases in loading rates in novice BF16 and minimalist26 runners without instruction; suggesting that instruction may be playing a role. Kinematics indicate that these participants often continued to RFS while running BF or in minimal shoes. These studies, combined with additional literature,3 and 27 IWR-1 molecular weight selleckchem demonstrate that not all runners convert to an FFS pattern when transitioning to BF running. Studies report that BF runners who RFS, have significantly higher loading rates than forefoot strikers and shod runners who
RFS.3, 24 and 25 Increased loading rates of the VGRF have been linked to a number of common running-related injuries.6, 7 and 8 Additionally, it has been shown that RFS runners are 2.5 times as likely to had a retrospective, repetitive stress injury than FFS runners.28 The use of feedback and instruction likely encouraged an FFS pattern as runners transitioned to BF running. Evaluation of high-speed video indicated that 96% of novice BF runners were able to adopt an FFS pattern. This altered strike pattern likely contributed to decreased loading rates during the BF condition. Literature reporting loading rates between BF runners who employ an FFS pattern and shod runners is extremely limited.25 Lieberman et al.3 reported no overall difference about in loading rates between BF FFS and shod runners. This
is in contrast to the current study and a recent study by Shih et al.24 where habitually shod RFS runners were asked to run BF and shod with both an FFS and RFS pattern. Confidence intervals on each condition indicated that loading rates were significantly reduced for an FFS pattern while BF and shod compared to an RFS pattern while shod. Importantly, participants in this study were told to use a specific strike pattern and given a brief time to practice an FFS before data were collected. Considered collectively, the results of these recent studies imply that not all FFS patterns are equivalent. Not all BF runners who make initial contact with the ground on the front of the foot may necessarily be successful at significantly reducing loading rates. The marked decrease in loading rates observed in this study may be partly attributed to the use of real-time feedback.