Forefoot bending stiffness, running economy and kinematics during overground running. (3rd May 2016)

• Record Type: Journal Article
• Authors: Madden, Ryan; Sakaguchi, Masanori; Tomaras, Elias K.; Wannop, John W.; Stefanyshyn, Darren
• Is Part Of: Footwear science. Volume 8:Number 2(2016)
• Page Start: 91
• Page End: 98
• Publication Date: 2016-05-03
• Subjects: bending -- longitudinal stiffness -- running shoe -- sagittal plane kinematics -- metatarsals -- biomechanics; Footwear -- Periodicals; Footwear industry -- Periodicals; Footwear -- Health aspects; Footwear; Footwear -- Health aspects; Footwear industry; Periodicals; 685.3
• DOI: 10.1080/19424280.2015.1130754
• Languages: English
• ISSNs: 1942-4280

Abstract

Abstract : Previous research has shown that altering forefoot (FF) bending stiffness can enhance running economy; however, the mechanism behind the changes in running economy remains unknown. Therefore, the purpose of this study was to investigate the relationship between forefoot bending stiffness, running economy, and lower limb kinematics during overground running. Eighteen aerobically fit recreational male athletes performed overground running using a portable metabolic analysis system to measure oxygen consumption in two footwear conditions with different forefoot bending stiffness. Sagittal plane kinematic data of the metatarsophalangeal, ankle, and knee joints were recorded using a high-speed camera. On average, there was no difference in running economy when running in the Stiff shoe ( O2 = 38.1 ± 5.4 mL/kg/min) compared to the Control shoe ( O2 = 37.7 ± 5.8 mL/kg/min, p = 0.11). On an individual basis, 10 athletes (Responders) improved their running economy with increased FF bending stiffness (∆ O2 = −2.9%), while eight athletes (Non-Responders) worsened or did not improve their running economy in a stiff shoe (∆ O2 = +1.0%). In stiff footwear, Responders experienced kinematic changes at the ankle joint (decreased angular velocity) that likely resulted in decreased energy requirement for muscular contractions due to a presumed shift on their individual force–velocity relationship. The lack of improvement in running economy by the Non-Responders may be attributed to a presumed lack of a shift in the force–velocity relationship of the calf musculature. Instead, Non-Responders experienced kinematic changes (increased ankle plantarflexion during push phase with stiff footwear) that likely hindered their moment-generating capability potentially due to a shift on their individual force–length relationship. These findings represent important progress towards explaining inter-individual changes in running economy with different footwear bending stiffness.