Effect of Specific Gait Modifications on Medial Knee Loading, Metabolic Cost and Perception of Task Difficulty
Background: The metabolic cost and cognitive demand of altering natural gait have not been well studied. The purpose of this investigation was to assess three modified patterns – toe out, ipsilateral trunk lean and a medial weight shift at the foot – on the basis of 1) medial knee joint load reduction, 2) metabolic cost of performance and 3) subject perception of task difficulty.
Methods: 12 healthy individuals underwent 3 dimensional motion analysis and metabolic testing to assess the gait mechanics and energy expenditure of natural gait and the three experimental gait patterns, performed to a self-selected moderate degree. Walking speed was controlled. Perceived workload was assessed using the NASA Task Load Index.
Findings: Trunk lean significantly reduced first peak knee adduction moment (↓32%, P < 0.001) as well as KAM impulse (↓35%, P < 0.001), but was costly in terms of energy expenditure (↑11%, P < 0.001) and perceived workload (↑1178%, P < 0.001). A moderate toe-out pattern significantly reduced the second peak knee adduction moment (↓32%, P < 0.001) and KAM impulse (↓14%, P = 0.026), but had no effect on the first peak. Conversely, toe-out was least demanding in terms of additional energy expenditure (↑2%, P = 0.001) and perceived workload (↑314%, P = 0.001). Medial shift did not reduce knee adduction moment.
Interpretation: The prioritization of joint load reduction versus additional metabolic and cognitive demands could play a substantial role in the clinical decision making process of selecting a modified gait pattern.
Copyright © 2013, Elsevier
Caldwell, Lydia K.; Laubach, Lloyd L.; and Barrios, Joaquin Alberto, "Effect of Specific Gait Modifications on Medial Knee Loading, Metabolic Cost and Perception of Task Difficulty" (2013). Physical Therapy Faculty Publications. 70.