Abstract
1684 Harness supported treadmill ambulation has been recommended for patients as a way of decreasing loads on the healing tissues, conserving energy and reducing pain. To determine the degree of changes in muscle activation and energy cost, our purpose was to quantify muscle activation levels around the knee and metabolic responses during harness supported treadmill walking. Ten healthy recreational athletes (age = 28.9 ± 7.8 years) exercised on the treadmill, walking at 1.34 m/sec (3.0 mph) with 0% grade at full body weight(FBW), 20% and 40% body weight supported (BWS). Subjects walked for five minutes for each harness supported condition. Muscle activity (EMG) was monitored with telemetry for 6 muscles; vastus lateralis, vastus medialis, rectus femoris, biceps femoris, medial hamstrings and gastrocnemius. Oxygen consumption was collected by open circuit spirometry and heart rate was collected by a heartwatch. Average EMG amplitude was normalized using the FBW amplitude as the reference denominator. Muscle activity, oxygen consumption and heart rate were analyzed (ANOVA) across harness supported conditions. At 20% BWS, average EMG activity decreased to 91.6, 96.9 and 90.0% of the FBW value for the quadriceps, hamstrings and gastrocnemius respectively (all p> 0.05). At 40% BWS, quadriceps activity declined to 72.8% of FBW value (p< 0.05), but the hamstrings and gastrocnemius changes (85.9 and 91.9% of FBW value) were not significant. Oxygen consumption decreased by 6% (20% BWS) and by 12% (40% BWS) from FBW (p < 0.05). Heart rate did not change significantly for any of the conditions. These data suggest that BWS ambulation reduces energy cost, but doesn't significantly alter muscle activation, except for the quadriceps at 40% BWS.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call