The motor and the brake of the trailing leg in human walking: transtibial amputation limits ankle-knee torque covariation.

Lower-limb amputation limits inherent motor abundance in the locomotor system and impairs walking mechanics. Able-bodied walkers vary ankle torque to adjust step-to-step leg force production as measured by resultant ground reaction forces. Simultaneously, knee torque covaries with ankle torque to act as a brake, resulting in consistent peak leg power output measured by external mechanical power generated on the center of mass.

Texting during stair negotiation and implications for fall risk.

Background/aim: Walking requires the integration of the sensory and motor systems. Cognitive distractions have been shown to interfere with negotiation of complex walking environments, especially in populations at greater risk for falls (e.g.