On the west coast I think it comes down to three programs: UC Davis, UW Seattle, and Stanford. Of the three, I think that UC Davis is the most musculoskeletally-oriented and UW Seattle is by-far the most inpatient-oriented (they are slowly trying to incorporate more MS, pain, and interventional stuff but are still a far way from Spaulding, Mayo, Michigan, or Kessler.
I rotated at Seattle and have to say that it is a strong program overall with an excellent reputation within PM&R. The residents are busier than at most programs, the inpatient load is heavy, and the amount of general medical issues you are expected to handle as opposed to straight rehab is high. The EMG training is also very solid. However, almost every single Seattle resident that is serious about musculoskeletal medicine does a fellowship after residency usually at Michigan or Mayo. This has been the trend for the last 5 years. The training philosophy of the program is that sports, spine, musculoskeletal, and pain are disciplines best pursued at the fellowship training level and residency should concentrate more on traditional inpatient rehab and electrodiagnostic medicine. This is increasingly being viewed as a minority view within the field.
I did not rotate at Stanford, but have heard that the program suffers from a lack of identity within the institution. PM&R at Stanford, if I remember correctly, is a division of Functional Restoration which is controlled mostly by Ortho. I believe that the training is probably adequate and the biggest bonus is being in the SF Bay Area. Stanford does have some good connections within the spine rehab community (the Saal brothers who invented IDET trained there and are well-known nationally and internationally).
UC Davis is a small program and may lack some exposure to some areas of rehab medicine. However, in comparison to UW and Stanford, I think UC Davis is the most musculoskeletally-oriented of the three. The program is working more and more closely with the anesthesia-based pain program and I think the residents may get some fair exposure to interventional pain procedures.
I can't comment on any programs in southern CA.