Walking at a slow speed up a moderate incline is an alternative exercise strategy for obese adults that may reduce the risk of musculoskeletal injury and pathological disease associated with brisk, level walking and provide proper cardiovascular stimulus for weight management. Decreased walking speeds combined with moderate inclines reduces lower extremity net muscle moments (NMM) compared with faster, level walking.
Ehlen and associates measured oxygen consumption, ground reaction forces, and 3-dimensional lower extremity kinematics while 12 obese adult volunteers walked on a treadmill at several speed and grade combinations. For each condition, they calculated metabolic rate; loading rates; and NMM at the hip, knee, and ankle.
Metabolic rates were similar across trials and were of moderate intensity. The maximum normal force loading rate increased as the walking speed increased. Peak NMM were smaller during the slower speed/moderate incline trials and increased as the speed increased and incline decreased. Peak knee extension and adduction moments were reduced when patients walked slower and uphill.
The authors noted that walking at slower speeds reduces the perceived exertion of the exercise, which may result in increased activity time and adherence, and that their findings support an exercise prescription specific to treadmill rather than overground walking.