following chemo had severe pain in feet and progressively clawed hands, both on waking but with feet progressively during the day too, esp from evening, then from afternoon on... not just pain but so bad it made me cry to walk some days and with the hands struggled to open a jar or turn a handle, and it was like they had grit in them, really stiff and immobile... got dx'd with inflammatory tenosynovitis, put on prednisolone 14 days, helped a lot, then NSAIDs (Meloxicam), also helped eventually, and 20,000mg omega 3s also helped a lot... and after over a year with it it is mostly gone!!! (hoo-ray! hope it stays gone). Did have severe stabbing pains in the toes at the start of it all too... was told it was probably 'peripheral neuropathy' and would go away... and that part did...the rest of it lasted around 1.5years and only stopped with the steroids/omega 3s/NSAIDs

but a few months after the feet/hands was dx'd with central apnea, a year later had severe polyuria (started 3-4L a day, then up to 5-8L a day), final conclusion was the latter was autonomic neuropathy as a result of chemo.... so essentially, part of chemo recovery.

what helped for the feet/hands... MASSAGE SANDALS beside the bed, ironic because who'd have dreamed that those painful bobbly sandals could help immensely painful rigid tissue in the feet... but it helped to at least walk and the pain went sooner... and all things anti-inflammatory... I'd suggest he gets to a rheumatologist, they MRI his feet and take it from there.

good luck with it.
on the bright side we're alive because of chemo
but living with chronic pain with no hope on the horizon was immensely despairing.
taking it as a buddhist challenge and viewing it in a Taoist framework helped me a lot too.

but it did take a lot of adapting too... mentally, emotionally and the fatigue it causes with pain just draining you daily.

hang in there