The influence of flexibility on the economy of walking and jogging

The relationship of 11 measures of trunk and lower limb flexibility to the economy of treadmill walking and jogging as measured by steady-state oxygen consumption (VO2) was studied. Subjects (38 women, 62 men, aged 20-62 years) were tested at six speeds between 53.6 and 187.7 m/min. By combining scores from all flexibility tests, and beginning at speeds of 107.3 m/min, the "tightest" third used significantly less O2/m/kg (9%, p less than 0.05) than the "loosest" third, with "normals" in between. Two tests, trunk rotation and lower limb turnout, gave the best separation for walking/jogging economy, with the "tightest" third differing significantly from the "loosest" (8-12%) at all speeds tested (ANOVA with Scheffe). We conclude that nonpathological musculoskeletal tightness was associated with a decreased steady-state VO2 for treadmill walking and jogging.