The Company of Biologists

Table 1.

Terms used in this study to compare mechanical patterns of the center of mass to gait patterns of the limbs

Whole-body mechanics (patterns of center-of-mass fluctuation)^{^a}

Pendular mechanics

Inverted pendulum-like mechanism

Spring mechanics

Spring-mass mechanism

Gaits (patterns of footfalls)^{^b}

Walk

Duty factor >50% (includes several possible walking gaits^*)

Run

Duty factor <50% (includes several possible running gaits^*)

Trot

Limb phase 50±10% (diagonal couplet gait)

Walking trot

Limb phase 50±10% (with >50% duty factor)

Running trot

Limb phase 50±10% (with <50% duty factor)

Strides

Aerial

Steps separated by periods with no limb contact with the ground

Non-aerial

Steps overlapping — continuous ground contact by at least one limb

Cavagna et al., 1977.

Hildebrand, 1976.

Determined by duty factor and limb phase.