When executed correctly, gentle, weight-bearing movements like sitting, squatting and bending will stretch and strengthen thigh muscles, which support the knees. Movement increases synovial fluid in the joints, nourishing and lubricating them. The joints become more slippery and move more easily. Tai chi, with its gentle, flowing, low-impact movements—can be an essential component in a fitness regimen designed to keep knees healthy and pain-free with a full range of motion.
http://www.taichi.ca/tai-chi-for-physical-health-taiji-quan-qi-gong-biomechanics-chronic-pain-balance-posture-vital-energy-mississauga-brampton-streetsville-cooksville-port-credit-vaughan-maple-etobicoke-toronto/strengthen-and-protect-knee-joints-with-tai-chi/
Protect Your Garage Door during Winter Weather
The weather can also wreak havoc on your garage door. Ice and snow builds up beneath the garage door, freezing it shut. Metal components contract and seize up in extreme temperatures. Old lubricating grease hardens when temperatures drop, gumming up the tracks. While some issues cause minor inconveniences, others can lead to expensive damage to your garage door or garage opener.
http://www.nuvogarage.com/garage-door/protect-your-garage-door-during-winter-weather/