Year: 2016
Type: article
Abstract: The human gluteus maximus is uniquely robust among primates (Stern, 1972;Lieberman et al., 2006).The large muscle's evolutionary role has long been debated and most recently explained in the Endurance Running (ER) Hypothesis as an adaptation for trunk balance in ER among early Homo (Bramble and Lieberman, 2004;Lieberman et al., 2006).Few studies have addressed trunk biomechanics in relation to barefoot running, the most likely foot condition of the hominin evolutionary past (Lieberman et al., 2010).Thus, this thesis further tests the ER Hypothesis by investigating the foot condition effect, barefoot and shod, on trunk kinematics and gluteus activity relative to trunk pitch.Kinematic and electromyographic data were collected from twenty-four adults: twelve males and twelve females.Subjects walked and ran on a treadmill at four speeds and three speeds, respectively, while shod and while barefoot.Sagittal plane trunk, thigh, and foot kinematics were calculated at heel strike and following.Gluteus maximus electromyographic data were calculated by average amplitude around foot contact.Joint angles of the trunk, thigh, and foot significantly differed between gaits within a single speed, between foot conditions within a single speed, and across speeds within a single gait.In contrast, muscle amplitude significantly differed across speeds within a single gait but not between gaits or between foot conditions at a single speed.Trunk forward pitch rate at foot strike increased with running speed, as did gluteus maximus activity.Although differences in magnitude of gluteus maximus contraction did not differ between shod and barefoot running, increased gait speed independent of foot condition was associated with increased pitching of the trunk and greater gluteus maximus magnitude.
Author: Lauren N. Heitkamp
Institution: University of Cincinnati
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2524460895