Inclusion Criteria: * All subjects \[sIBM and BMD must be ambulatory and have identifiable atrophy of the quadriceps muscle with muscle weakness ≥2 standard deviations below predicted using quantitative muscle testing (maximum voluntary isometric strength testing), and difficulty getting out of chairs, climbing stairs, and getting up from the floor. * sIBM patients include males and post-menopause females of any ethnic or racial group. Diagnosis of sIBM is based on previously published criteria that include distribution of weakness (knee extensor weakness, finger flexor weakness) and histological presence of inflammation and vacuolar myopathy. Patients with inflammation, vacuolar changes and intracellular amyloid deposits or 15/18nm filaments fulfill criteria irrespective of clinical features. * BMD patients include adult males (\>18yo) of any ethnic or racial group with proven mutation of dystrophin gene and continued ambulation after age 15 years old. * Ability to cooperate for muscle testing * Deficit in muscle strength greater than 2 standard deviation below age expectations * Willingness of sexually active subjects with reproductive capacity (only male population) to practice reliable method of contraception until two negative sperm samples are obtained post gene transfer Exclusion Criteria: * Active viral infection * History or evidence of active infection with hepatitis C, hepatitis A or B, or HIV * Patients with any other cause of muscle weakness based on medical history and screening physical exam including: myopathy (other dystrophies, polymyositis, and dermatomyositis), neuropathy (from any cause), myasthenia gravis, and weakness related to degenerative joint disease of the spine. * Ongoing immunosuppressive therapy or immunosuppressive therapy within 3 months of starting the trial (e.g. corticosteroids, cyclosporine, tacrolimus, methotrexate, cyclophosphamide, intravenous immunoglobulin, rituximab) * Concomitant illness or requirement for chronic drug treatment that in the opinion of the PI creates unnecessary risks for gene transfer. Patients taking any of the following drugs will be excluded: drugs for treatment of myopathy or neuropathy or agents used to treat diabetes mellitus * Knee or ankle contractures preventing proper muscle strength testing * Patients with AAV1 neutralizing antibody titers ≥ 1:1600 as determined by ELISA immunoassay * Patients with history of angina and patients with past history of myocardial infarction in the past 6 months