Hello
Im dr.hema physiotherapist.
Welcome to health care magic.
Usually I ask my patients to avoid exercises in severe
spinal stenosis especially for (as you mentioned pain radiates to leg) back and abdominal muscles.but in mean time try to be active with your daily activities and can start with general body exercises to all other joints regularly.
Avoid bending at waist waist.
Avoid overextended posture as it may worsen the stenosis.
Take proper rest so your back is flat on bed and rests fully.
You can use pillows under knees while sleeping.
Avoid using rough roads if you go out.lifting weights.
Mild stretches to calf muscles.
Isometric exercise for back can be done.
Hot water fermentation when you have more pain to back and legs.
You can talk to your dr about
physical therapy modalities for pain and if you are willing in conservative management.
Hope it helps.
In doubt please do reply.