Left leg pain/paraesthesia and disc issues for rehab

I am currently treating 49 yr old male first reported lumbar injury with left leg numbness at work Feb this yr (though started halfway through 2011). He has had scans done in May 2011 which indicate L3 left lateral disc protrusion impinging on left L3 nerve root and osteophytic lipping at this level. He also has severe L5/S1 disc degeneration. He has had a followup CT Scan this yr after the aggravation in Feb and there are minimal changes to the previous scan.
-Symptoms started with left leg pain to the knee, now has progressed to the foot.

Occupation: forklift driver. Injured back by driving over uneven and bumpy surfaces (forklifts have solid tyres). Currently does a lot of housework as is off work and psychologically needs to keep self busy/active.

Aggs: Walking (after 1-2 km gets strong leg and back pain), gardening (prolonged flexion), shovelling, rotation to left, lying prone.

Eases: Sitting (can sit for 1 hr and 1/2 but has difficulty after with getting up), being relaxed

24 hr: difficult to get comfortable, especially when on side, has to keep turning.

Lumbar spine movement: full flexion with mild lx pain, ext- very restricted and painful in lower back, lateral flexion- sore at end of both directions, rotation- left aggs, right relieving.
Posture: absent lumbar lordosis in sitting
PAVIMs-lumbar spine generally sensitive
Sensation: altered light touch sensation left foot and calf, anterior tibia region less affected.
Neural test: v positive left approx 20 deg SLR
Myotomes: L3, L5, S1 weaker left
Reflexes- left = right

Treatment of L5/S1 with right rot PPVIMs seems to relieve pain (especially some of the referred pain) but this is not long lasting. I have tried postural correction strategies and exercises. He says that a lumbar roll helps when sitting but when he was doing light lifting training exercises, his back felt less painful in a slouched position (particularly in the thoracic spine). I have given him some core stability exercises and encouraged him to stretch with right rotation and right lateral flexion as this seems to be the most relieving directions. I encourage him to avoid/modify bending tasks (lots of housework jobs) but don't want him to stop doing things as this is very important for him mentally.

He seems to be gradually improving but I think this is mostly natural healing. I am going to try more core stability exercises with him. I don't know if he will ever be able to go back to his original work duties. Any advice or suggestions?

As it turns out we made some improvements today. Pt had stiffness of left sided L3-5 and corresponding muscle spasm. Palpation and joint mobs in this area referred pain down the left leg. I then did some right rotation PPVIMs as per previous sessions (which usually eases leg pain) however today this seemed to be worsening leg symptoms.

I switched direction to left rotation PPVIMs and the leg pain eased altogether, there was only very slight local lower back pain and extension was much better (about 5 deg more and importantly it was painfree). I have a suspicion that he has turned a corner now- that we can start working into the stiffness as his body is allowing that now. Once we get more extension I think the rest will follow -being able to get a good neutral spine position for postural retraining and core stability exercises. I will keep everyone posted on this :)