Surely, as parent you must be concerned. A 22 month old child should be walking on his own without support. I would like to know a few things about his birth history. Was it a full term normal delivery and did he cry immediately? Any complications like seizures, severe jaundice
etc. during first 4 weeks?
Also let me know about other mile stones like age at which he started head holding,sitting, crawling, standing. If these were at normal time I would like to think of a muscular-skeletal problem. Consult an orthopedic specialist to rule out any deformity
,congenital dislocation of the hips or congenital muscular disorder.
You may send the answer to above queries at my email address: firstname.lastname@example.org
I shall be quite happy to help you further.
Best of luck.