Foot strike patterns and body alignment effects on muscle activity during running.

bioengineering;muscle activity;body allignment

Nicole Knapp

University:University of Louisville

Department:Bioengineering

关键词: bioengineering;    muscle activity;    body allignment;   

Others  :  https://ir.library.louisville.edu/cgi/viewcontent.cgi?article=3453&context=etd

美国|英语

来源: The Universite of Louisville's Institutional Repository

【 摘 要 】

The mechanics of the running stride was altered around the 1970s when shoes were released with an elevated heel (McDougall 2009). At this point in time a heel strike running style became increasingly common and has remained the popular pattern when running in traditional shoes. In fact, the exact same person has been seen to alter their stride when running in a traditional shoe where they heel strike verses barefoot where they take on a forefoot strike (Lieberman 2010). When an individual heel strikes, the ground reaction force is greater and contains an initial peak which is void in a forefoot strike. During a heel strike, a lot of force is generated in the knee (Kulmala 2013). In fact, it has been recommended to alter a stride from heel strike to forefoot strike if an individual is experiencing knee pain. However, Kulmala identified an increase in stress on the Achilles tendon when an individual utilizes a forefoot strike which leads to a different set of injuries. Another common problem identified while performing a forefoot strike is an increase in the activation time of the gastrocnemius muscles (Ahn 2014). The first aim of this study was created to identify the difference in muscle activity occurring during a heel strike pattern and a forefoot strike pattern. The second aim is designed to vii identify if adding a forward body tilt while performing a forefoot strike will alter the muscles activated in hopes of reducing the amount of activation at the calf. To assess the aims, a 3D motion capture analysis system as well as an EMG system were utilized. The EMG system was used to monitor tibialis anterior, medial gastrocnemius, lateral gastrocnemius, vastus lateralis, rectus femoris, semitendinosus, and biceps femoris muscle activity. Each of the 10 subjects underwent a testing period in which four different strides were assigned individually. Prior to data capture of each stride, the subject was allotted time to familiarize with the stride followed by two and a half minutes of running on the treadmill in which the last 15 seconds were recorded (EMG and motion capture). The motion capture data were processed to ensure the assigned stride was correctly performed. The EMG data was processed by a full wave rectification followed by a root mean square 50 ms moving window average and then normalized. During terminal swing, the three forefoot strike conditions had higher gastrocnemius, hamstring, and quadriceps