Metabolic and Biomechanical Effects of Velocity and Weight Support Using a Lower-Body Positive Pressure Device During Walking

Grabowski AM. Metabolic and biomechanical effects of velocity and weight support using a lower-body positive pressure device during walking.ObjectivesTo determine how changes in velocity and weight support affect metabolic power and ground reaction forces (GRFs) during walking using a lower-body positive pressure (LBPP) device. To find specific velocity and weight combinations that require similar aerobic demands but different peak GRFs.DesignRepeated measures.SettingUniversity research laboratory.ParticipantsHealthy volunteer subjects (N=10).InterventionsSubjects walked 1.00, 1.25, and 1.50m/s on a force-measuring treadmill at normal weight (1.0 body weight [BW]) and at several fractions of BW (.25, .50, .75, .85 BW). The treadmill was enclosed within an LBPP apparatus that supported BW.Main Outcome MeasuresMetabolic power, GRFs, and stride kinematics.ResultsAt faster velocities, peak GRFs and metabolic demands were greater. In contrast, walking at lower fractions of BW attenuated peak GRFs and reduced metabolic demand compared with normal weight walking. Many combinations of velocity and BW resulted in similar aerobic demands, yet walking faster with weight support lowered peak GRFs compared with normal weight walking.ConclusionsManipulating velocity and weight using an LBPP device during treadmill walking can reduce force yet maintain cardiorespiratory demand. Thus, LBPP treadmill training devices could be highly effective for rehabilitation after orthopedic injury and/or orthopedic procedures.