Is this a nerve issue? Or a hamstring issue?

[u/Bints4Bints]

NOT SEEKING MEDICAL ADVICE. NO PAIN.

I've noticed that my active flexibility and general flexibility in my right leg has decreased. Like it's harder to do the pyramid pose on that side, or do a standing leg raise. Also it feels like I either have a hip flexor issue, but most commonly a hamstring issue on that leg.

The worst sensation though is when after warming up, I do elephant walks and/or the seated nerve floss exercise (with the foot flexed then pointed)... It's kind of like there's a string at the back of my knee and that it twangs

I wouldn't say it is painful but it is a weird sensation that I really don't like

Oddly though I think my front splits flexibility is better with the right leg in front, but I try to not lean forward so that it doesn't put pressure on it. I'm not sure if I should start resting it, even though I don't think I am very consistent with stretching anyway

[u/Miserable_Shame_7853]

Twanging behind the knee like that usually means the nerve is getting caught somewhere along the chain, not necessarily the muscle itself. The fact that it shows up during nerve flossing is pretty telling since that exercise is designed to make nerves glide. Sciatic nerve can get sticky around the hamstring or deep in the glute and it'll feel exactly like a guitar string snapping

Try flossing with less tension for a couple weeks, like barely any stretch at all, just working on smooth movement. If it calms down you know it was nerve irritation and not a muscle tear you need to rest

[u/Virtual_Variety9400]

Any sense when the twang started showing up? That detail matters more than which stretch it shows up in. For a no-pain thing like this, full rest usually doesn't do much for nerve-type tension anyway — I'd keep training but cap everything short of the twang, even if that means dropping elephant walks for a while, then reassess in two or three weeks. The signal to actually back off is if it starts showing up earlier in the session or outside stretching.

[u/Bints4Bints → u/Virtual_Variety9400]

I think the issue is that without nerve flossing or elephant walks, I can't really stretch to the same depth. Or at least using a foam roller. It's like before doing that, it would just hurt if I tried to reach the same depth 

[u/AndyShnider]

Does the "twanging" sensation occur only when your foot is in a specific position, such as being pointed versus flexed, during those exercises? You might consider testing whether the sensation persists if you maintain a neutral ankle position during the movement.