Barefoot "Standing Heel Raises" are a great way to strengthen and stretch the toes, ankles and knees

Begin behind a chair for safety with the feet about hip distance apart. Shift your weight onto your toes with straight knees and lengthened spine. Lift your heels as high as comfortable. Slowly lower back to the floor and repeat 8 to 20 times.

A couple other versions: One is to take the heels up and hold for a 5 count.
Another you can have a 4 count as the heels go up, hold for a 2 count, then 4 count as the heels drop to the floor, hold for a 2 count and repeat.

Benefits: Strengthens knees and hips, improves balance and loosens the major muscle groups at the back of the lower leg. You'll feel the stretch in your calves. Helps stretch and strengthen your calf muscles: gastrocnemius and soleus.

Happy & Healthy,
Yoga Chuck