Be careful about the wording you use. I personally be very careful to NOT say "Heavy" but then qualify it as being capable of only some portion of Heavy. This is particulary true if you are completing a State form that allows only a single check mark or initial to indicate the demand level. And, as mentioned above, you should consider the client's abilities or restrictions in the areas of standing and awkward postures: if these are limited he/she may not be truly capable of Strength in the category linked to lifting only.

Just looking at that lift I would say they fall in the medium PDC.  In my summaries I have used statements such as, "...in the medium physical demand category with some ability in the heavy.  The client demonstrated safe material handling ability of up to 70 pounds occasionally when lifting floor to shoulder level..."

Don't forget to look at the entire performance of the person during the evaluation (stand/walk, other material handling, MET testing, endurance, etc.) when determining a PDC.

Shelia-you could say that the client's abilities fall in the Heavy PDC.  To put a finer point on the statement, you could also say that the client's abilities fall in the Heavy PDC and is fully capable of meeting the strength demands for Medium work.  I would not say that the client's demonstrated abilties meet the demands for Heavy work-as the person did not lift 100 lbs.  Additionally, most of the evaluators that I have discussed this with tend to observe the floor level lift for determining PDC, but also agree that if there is a significant disparity between floor level and knuckle/waist level lifting-the lesser of the two would determin the PDC ranking when no job match is available.