Of course. You can feel weakness in any body part. When you get excited or anxious, you often feel wobbly, especially in your legs and knees, as if they are about to collapse.
Susan had to be put into braces due to her weak knees.
no
Weak Knees - 1927 was released on: USA: 20 June 1927
Weak Knees - 1925 was released on: USA: 1 February 1925
deadpool
The cast of Weak Knees - 1925 includes: Cliff Bowes Virginia Vance
The cast of Weak Knees - 1927 includes: Henry Roquemore Lewis Sargent Wanda Wiley
love or lust
Delayed Teen Angst - 2009 Weak in the Knees 1-5 was released on: USA: 6 June 2009
It's not an idiom - it's a description of what happens when you get nervous and excited. Your legs feel wobbly and you might even fall over because your knees get weak and collapse underneath you.
90210 - 2008 Sweaty Palms and Weak Knees 2-17 is rated/received certificates of: Netherlands:6 USA:TV-14
Your knees would be less strong because of all of the pressure that you put on them when you walk...and after fifty years of walking, then the knees would be very weak.