A tricky patient! Good at diagnosing?

Ok, so I saw a patient the other day (19yr old male, physio student actually) and this is his subjective/objective:

--> Lower back stiffness: Had it for a while now, feels like he is starting to lose his lordosis .... finds it increasingly hard to stay in a neutral pelvis position, he falls back into posterior pelvis tilt and consciously has to hold a good posture.
--> Gradual increase in pain in the Rt posterior thigh, sometimes eminating down to the superoposterior aspect of the knee.
* Feels like the pain is slightly more on the lateral aspect of the thigh, not centered.
--> Rides a motorbike and wears a heavy bag (10kg+) most days at uni (monday to friday)

Performed a slump test and felt pain in both legs, more-so in the Rt, but had very tight hamstrings which may have contributed to the pain and short hip flexors (only get to neutral) & rec fem (Modified Thomas test).

He also noticed his Rt G.max does not work all the time ... i'm thinking hamstrings synergistically dominating. But it is strong, it just doesn't activate sometimes when extending his thigh... so def. an activation issue here.

Has felt the 'numbing/hot/uncomfortable' pain come on more-so recently over the last couple of weeks since he is studying and sitting down a lot. Sitting for long periods aggravates/irritates it. No skin observations, completely normal except for the uncomfortable pain.

I'll summarise his problem haha:
- Lower-back stiffness (L2-L4) region
- Constant numbing/warm/niggling/annoying discomfort in Rt posterolateral thigh, sometimes reaching as low as the posterolateral knee and sometimes reaching the big toe and medial aspect of his leg and foot (yep goes from lateral to medial).
- Rides a motorbike
- Wears a heavy bag most days
- Increasingly difficult to sit with a neutral pelvis, constantly in posterior pelvis tilt and has to constantly correct posture by sitting up.
- No spondylolisthesis (no step deformity)
- Very tight hamstrings and hip flexors and rec fem (both sides)
- Modified slump tests showed pain (but very tight hamstrings)
- SLR's performed ... again tight hamstrings, no back pain.

Any thoughts? Sorry for the gargantuan post.

Turns out it was reduced disk height, most likely due to disc degeneration which was obviously causing the disc to bulge backward adding pressure on the patients sciatic nerve hence the sciatica.