An α7β1 integrin modulatory agent for use in the treatment of muscular dystrophy in a subject or for use in the enhancement of muscle regeneration, repair, or maintenance in a subject or for use in the prospective prevention or reduction of muscle injury or damage in a subject: wherein said α7β1 integrin modulatory agent has a formula selected from wherein Y 1 and Y 2 independently is selected from oxygen, sulfur, or NR b, wherein R b is selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heterocyclyl, or substituted heterocyclyl; wherein R 1 is selected from C 1-10 alkyl, substituted C 1-10 alkyl, C 1-10 alkoxy, substituted C 1-10 alkoxy, acyl, acylamino, acyloxy, acylC 1-10 alkyloxy, amino, substituted amino, aminoacyl, aminocarbonylC 1-10 alkyl, aminocarbonylamino, aminodicarbonylamino, aminocarbonyloxy, aminosulfonyl, C 6-15 aryl, substituted C 6-15 aryl, C 6-15 aryloxy, substituted C 6-15 aryloxy, C 6-15 arylthio, substituted C 6-15 arylthio, carboxyl, carboxyester, (carboxyester)amino, (carboxyester)oxy, cyano, C 3-8 cycloalkyl, substituted C 3-8 cycloalkyl, (C 3-8 cycloalkyl)oxy, substituted (C 3-8 cycloalkyl)oxy, (C 3-8 cycloalkyl)thio, substituted (C 3-8 cycloalkyl)thio, halo, hydroxyl, C 1-10 heteroaryl, substituted C 1-10 heteroaryl, C 1-10 heteroaryloxy, substituted C 1-10 heteroaryloxy, C 1-10 heteroarylthio, substituted C 1-10 heteroarylthio, C 2-10 heterocyclyl, C 2-10 substituted heterocyclyl, C 2-10 heterocyclyloxy, substituted C 2-10 heterocyclyloxy, C 2-10 heterocyclylthio, substituted C 2-10 heterocyclylthio, imino, oxo, sulfonyl, sulfonylamino, thiol, C 1-10 alkylthio, substituted C 1-10 alkythio, or thiocarbonyl; or two R 1 substituents, together with the atom to which each is bound, may form ring selected from a C 6-15 aryl, substituted C 6-15 aryl, C 3-8 cycloalkyl, substituted C 3-8 cycloalkyl, C 1-10 heteroaryl, substituted C 1-10 heteroaryl, C 2-10 substituted heterocyclyl, or C 2-10 heterocyclyloxy; n may be zero, 1, 2, 3, 4, or 5; or a combination of any of these compounds; wherein the α7β1 integrin modulatory agent increases α7β1 integrin expression or activity as compared to α7β1 integrin expression or activity prior to said use; and wherein the muscular dystrophy is merosin deficient congenital muscular dystrophy Type 1A (MDC1A), merosin deficient congenital muscular dystrophy Type 1D (MDC1D), limb-girdle muscular dystrophy (LGMD), Duchenne muscular dystrophy, Fukuyama congenital muscular dystrophy (FCMD) or Facioscapulohumeral muscular dystrophy (FHMD). wherein Y 1 and Y 2 independently is selected from oxygen, sulfur, or NR b, wherein R b is selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heterocyclyl, or substituted heterocyclyl; wherein R 1 is selected from C 1-10 alkyl, substituted C 1-10 alkyl, C 1-10 alkoxy, substituted C 1-10 alkoxy, acyl, acylamino, acyloxy, acylC 1-10 alkyloxy, amino, substituted amino, aminoacyl, aminocarbonylC 1-10 alkyl, aminocarbonylamino, aminodicarbonylamino, aminocarbonyloxy, aminosulfonyl, C 6-15 aryl, substituted C 6-15 aryl, C 6-15 aryloxy, substituted C 6-15 aryloxy, C 6-15 arylthio, substituted C 6-15 arylthio, carboxyl, carboxyester, (carboxyester)amino, (carboxyester)oxy, cyano, C 3-8 cycloalkyl, substituted C 3-8 cycloalkyl, (C 3-8 cycloalkyl)oxy, substituted (C 3-8 cycloalkyl)oxy, (C 3-8 cycloalkyl)thio, substituted (C 3-8 cycloalkyl)thio, halo, hydroxyl, C 1-10 heteroaryl, substituted C 1-10 heteroaryl, C 1-10 heteroaryloxy, substituted C 1-10 heteroaryloxy, C 1-10 heteroarylthio, substituted C 1-10 heteroarylthio, C 2-10 heterocyclyl, C 2-10 substituted heterocyclyl, C 2-10 heterocyclyloxy, substituted C 2-10 heterocyclyloxy, C 2-10 heterocyclylthio, substituted C 2-10 heterocyclylthio, imino, oxo, sulfonyl, sulfonylamino, thiol, C 1-10 alkylthio, substituted C 1-10 alkythio, or thiocarbonyl; or two R 1 substituents, together with the atom to which each is bound, may form ring selected from a C 6-15 aryl, substituted C 6-15 aryl, C 3-8 cycloalkyl, substituted C 3-8 cycloalkyl, C 1-10 heteroaryl, substituted C 1-10 heteroaryl, C 2-10 substituted heterocyclyl, or C 2-10 heterocyclyloxy; n may be zero, 1, 2, 3, 4, or 5; or a combination of any of these compounds; wherein the α7β1 integrin modulatory agent increases α7β1 integrin expression or activity as compared to α7β1 integrin expression or activity prior to said use; and wherein the muscular dystrophy is merosin deficient congenital muscular dystrophy Type 1A (MDC1A), merosin deficient congenital muscular dystrophy Type 1D (MDC1D), limb-girdle muscular dystrophy (LGMD), Duchenne muscular dystrophy, Fukuyama congenital muscular dystrophy (FCMD) or Facioscapulohumeral muscular dystrophy (FHMD).