Why some elderly take stair ascending slowly: PAD, Peripheral arterial disease.

When we think of slowing gait we think of the elderly. There is nothing new in this regard and there have been plenty of papers supporting the cognitive decline the coincides with this aging population. There is even correlation to increased fall risk, which matches up with significant  fall mortality studies.  Reduced, especially right sided, hippocampus volume and function is the current suspect in most research, and it is linked to some impairments in non-verbal memory and the slowing of gait.

Here, we see that PAD (peripheral arterial disease) can also cause a slowing of gait, particularly in stair ascent in this particular study. PAD can cause intermittent claudication pain in the calf and result in altered gait mechanics during level walking as well. The study found that those with claudication walked more slowly than healthy controls.  They also found that there was reduced vertical ground reactive forces, reduced knee extensor moment during forward continuance, reduced ankle angular velocity at peak moment and reduced ankle power generation.  They were also able to determine that the slower gait was related to the claudicated limb, that limb was the one that set the speed of gait. In other words, the system down regulated to the affected limb's capability. The study highlighted the importance of maintaining plantarflexor strength and power in those with peripheral arterial disease with effective claudication.  

Sagittal plane joint kinetics during stair ascent in patients with peripheral arterial disease and intermittent claudication.  Stephanie L. King, Natalie Vanicek, Thomas D. O’Brien
http://www.gaitposture.com/article/S0966-6362(17)30102-9/abstract?platform=hootsuite