A mass effect could be a bone spur (osteophyte) or a bulging disc or a tumor or a hemangioma. It is difficult to say what it is on net. A bulging disc or osteophyte may respond to physiotherapy and pain medications. A tumor needs to be followed up and may be excised. Hemangiomas could also be treated conservatively or with surgery.
So, you need to find out what the mass effect is most likely to be. The treatment will depend on this diagnosis. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.
I also have a similar situation. I have a bulging disc in Ll3-L4 with a mass effect on L4 nerve root and I am not able to contract some muscles in my left glut and leg. It has been 2 weeks and still no response from a steroid pack, IBprof, flexeril, and heavy icing. I have absolutely no pain however I still can't contract my muscles. what do you suggest I do? is there a way to release the nerve root with exercise? alternatives?