Stance and swing phase costs in human walking.

Area of Science:

• Biomechanics
• Human locomotion
• Metabolic energy expenditure

Background:

• Historically, leg swing in human walking was considered passive with minimal metabolic cost.
• Previous estimates for leg swing costs vary widely (10-33% of net walking cost).
• Debate exists on whether double-limb support phases dominate walking's energetic cost.

Purpose of the Study:

• To investigate the metabolic cost of human walking.
• To estimate instantaneous energy consumption rates in individual muscles during locomotion.
• To clarify the energetic contributions of leg swing and stance phases to overall walking cost.

Main Methods:

• Utilized a modeling approach to estimate metabolic energy consumption.
• Calculated instantaneous energy consumption rates for individual muscles.
• Analyzed energy expenditure across the entire gait cycle at a typical walking speed and stride rate.

Main Results:

• Leg swing accounted for 29% of the total muscular cost of walking.
• Double-limb support and single-limb support phases represented 27% and 44% of total cost, respectively.
• Step-to-step transitions (including double-support) constituted 37% of the total walking cost.

Conclusions:

• Leg swing is a significant contributor to the metabolic cost of walking.
• Stance phase, particularly single-limb support, is the most costly phase.
• Increasing stride rate alters the cost distribution between swing and double-limb support phases.