A recording of the March 2021 "live" Qi Chat where Jeff discusses the fundamental ideas of having strong and stable legs from a Western medicine and Traditional Chinese Medicine point of view. Follow along with a routine where everyone practiced together. If you want to practice it again, this routine is now in the 'Iron and Silk' section as well:
https://qigongforvitality.vhx.tv/iron-and-silk-qigong-and-exercises/videos/iron-and-silk-leg-foundation-strength-12-mins

Time Markers for topics covered:
1min 47 - Intro
7min 28 - Lower body injuries
9min 45 - Progression of lower body problems
11min 32 - Root of most problems
15min 20 - Poll and Questionnaire
17min 30 - Alignment of Feet
21min 17 - Alignment of Knees
25min 42 - Alignment of Hips, Kua, Glutes and ‘Rockets’
30min 22 - General Concepts for lower body
31min 46 - Koala Walk
33min 55 - Feeling Qi
35min 25 - Learning and Practicing Concepts
51min - Lower body strength routine

Questions:
1:04:37 - Best exercise of strengthening foot
1:05:00 - Should you keep back flat when folding the kua?
1:05:55 - Best exercise for sacroiliac injury
1:06:16 - Exercise for plantar fasciitis
1:07:00 - Description of driving the heel while stepping
1:07:49 - Is the back vertical during horse stance?