About a year ago I felt a shooting pain in the outside of my knee when I was kneeling down to tie my lace (the knee which was not touching the floor) and it was a struggle to stand and straighten my leg as it felt as if it was locked in the bent position, this was followed by some swelling pain for about a week but not too bad.
Last week I was doing pistol squats and at the bottom of the first rep the same knee felt like it gave way and had the same feeling of being locked and unable to straighten, this time the pain is worse, and whenever I try to squat I hear/feel a popping noise in my knee.
From looking at pictures online it appears the pain is coming from the bottom of the LCL.
Do you have any advice on what I should do going forward please.
I would not be as confident that this is necessarily “coming” from the LCL. Meniscal injuries can sometimes present this way, although I’m not able to confidently make that diagnosis via the forum here either. We have a piece on that topic as well: A Second Opinion on Your Meniscus Injury | Barbell Medicine
However, with the nature of symptoms you’ve described here, I think consulting with a professional like a clinician from our rehab team, would be wise. These consults can be set up through the website, or you can seek out a professional local to you, if desired.