1999k-498 capacityanddisability complications congresses convalescence disabilityevaluation disabledpersons effectofenvironmenton employment energymetabolism humanbeings jurisprudence legislation malnutrition nutritiondisorders peoplewithdisabilities physicalexertion physiologicalaspects psychologicalaspects psychology qu125c2361984 rehabilitation socialsecurity taskperformanceandanalysis tropicalclimate tropicalmedicine tropics unitedstates vocationalqualifications vocationalrehabilitation w900m4841999 wb320p58032005 work workers'compensation