How do you train the gluteus maximus without causing knee or SI joint strain?

You can also think about not working the muscle through the full range of movement.

Train the muscle below the point of "strain." Once you feel discomfort, then you know that you are working in a range that exacerbates whatever SI joint pain you are experiencing.

Another idea is to perform hip extension on an arc barrel or a BOSU.

Good responses. Maybe while she is performing her hip exercises you could have her wear a band around her ankles to increase resistance and not working in the full range of motion, as Joanne suggested. Or you can have her ankle strapped in the cable machine while performing the prone hip exercises movements.

Hello Dorothy Waxman,

Walking up slight inclines can help and doing prone hip extensions. Make sure to keep the areas flexible, also. How about walking backwards in the pool?
Take care.

I agee with Natalie and Karin. Another good way to target the gluts is stand-up riding on a bicycle, either outside or on a spinning bike. Outside, add stand-up uphill to increase the overload.

Take care.

Good suggestions. I would stick with the moderate range of motion and isometric exercises until you find out the specifics of her condition. i.e. due to a fall, muscle imbalances, joint/ tendon laxicity, microfractures, joint degeneration, etc. Also, being a yoga instructor she may be hypermobile and working on increasing flexibility might exacerbate her condition.

Along with the answers above is to add an Elliptical training workout, pedaling backwards is great if she can tolerate it.

Foam rolling may help her also.

If she has not already seen a doctor or physical therapist, she may want to. I have found with clients with issues such as these that it is not the gluteous maximus that is always the culprit. For one it was a calf (soleus and achilles) issue. For another it was an adductor, gluteus medius issue.

You can also check her gait when walking. Some people, especially women, have a hip fall issue that can cause knee pain and stability issues over time. I've even heard of women having this issue due to quad VMO contraction issues. A physical therapist friend and I were just talking about these issues a few months ago and ways we can proactively help.

As some one suggested, a foam roller will help her to be able to identify where the issue may be stemming from, but an assessment with a physical therapist or orthopedist will help immensely!

Good luck! And take your time and encourage her to go slow. Most of those problems stem from long term issues and as such can take a long time to correct.