A typical disc herniation at L5-S1 will injure the S1 nerve which innervates the calf muscles (Gastroc and Soleus) as well as the gluteus maximus. This means that you will have weakness getting up on your toes (heel raises) and weakness of extending your hip. These weakness are more pronounced ascending and especially descending stairs. The act of muscle shortening (actively moving a joint instead of weighting an already locked joint) makes it much more difficult to get up on your toes vs. holding a locked ankle joint (“I can’t lift up to my toes on my right side, but I can stand on my toes (once I get up with help)”.
The good news it is 10 months since surgery and it can take up to 18 months to know the final healing results. Yes-PT is still important as you can strengthen the currently functioning muscle fibers to take over for the non-functioning ones. I’ll again point out 2 articles to read.