Table 2.

Age-Related Biomechanical and Neuromuscular Factors Contribute to a Loss of Motor Skill and an Increased Energy Cost of Walking for Older Adults

Biomechanical Factors		Neuromuscular Factors
Use of momentum	Moderating acceleration and deceleration	Pattern of peripheral muscle activation	Neural control
Insufficient loading of the limb transitioning to swing for gait initiation (23)	Heel strike poorly timed with push off (24)	Lack of inhibition of antagonist prior to agonist activation (23); excessive muscle activity at gait initiation (25)	Reduced (elicited) signal for stepping – lack of hip extension and loss of contribution of mechanical preflexes (15,16)
Stance limb not loaded through midstance in preparation for push off (15,26)	Large vertical displacement of the center of mass (15); reduced plantarflexor power (26)	Prolonged cocontraction of lower limb muscles (27); prolonged contraction and relaxation time (27)	Poor modulation of postural reflexes during the transition from standing to walking (loss of preflex) (15)
Trunk flexion (28), limited hip extension (26,28), and reduced ankle dorsiflexion (26)	Disrupted inverted pendulum (24); step width increased (26)	Trunk leading strategy (23,26); instability – additional corrective postural responses (23)	Slowness of movement Intentional guiding of limb movements – placing, step length (26)
		Inefficient mitochondrial function; de-energized muscle cell (29)