A tool for use in determining a dosage amount of a botulinum neurotoxin to be administered to a subject, the tool comprising: a first member having thereon a first row of numbers indicative of the weight of the subject and a second row of numbers indicative of a dosage amount of the botulinum neurotoxin to be administered to the subject, wherein the numbers in the first row indicating a specific weight are in latitudinal or radial alignment with corresponding numbers in the second row indicating the specific dosage amount to be administered to a subject having that specific weight, wherein the dosage amount corresponds to 5 to 15 units per kilogram of the total body weight of the subject per leg; and a second member; wherein the first and second members are in a relationship with one another such that one member may be moved by a user to provide an indication as to the dosage amount of the botulinum neurotoxin to be administered to a subject having a particular weight; and wherein the first member further has thereon a row of numbers indicative of the dosage amount of the botulinum neurotoxin to be administered to a particular muscle of the subject and the numbers in the row which indicate the specific dosage amount to be administered to the muscle of a subject having a specific weight are in longitudinal or radial alignment with corresponding numbers in the first row indicating that specific weight, wherein the dosage amount corresponds to 6 to 9 units per kilogram of the total body weight of the subject to be administered to an individual gastrocnemius muscle of the subject or wherein the dosage amount corresponds to 4 to 6 units per kilogram of the total body weight of the subject to be administered to an individual soleus muscle of the subject. a first member having thereon a first row of numbers indicative of the weight of the subject and a second row of numbers indicative of a dosage amount of the botulinum neurotoxin to be administered to the subject, wherein the numbers in the first row indicating a specific weight are in latitudinal or radial alignment with corresponding numbers in the second row indicating the specific dosage amount to be administered to a subject having that specific weight, wherein the dosage amount corresponds to 5 to 15 units per kilogram of the total body weight of the subject per leg; and a second member; wherein the first and second members are in a relationship with one another such that one member may be moved by a user to provide an indication as to the dosage amount of the botulinum neurotoxin to be administered to a subject having a particular weight; and wherein the first member further has thereon a row of numbers indicative of the dosage amount of the botulinum neurotoxin to be administered to a particular muscle of the subject and the numbers in the row which indicate the specific dosage amount to be administered to the muscle of a subject having a specific weight are in longitudinal or radial alignment with corresponding numbers in the first row indicating that specific weight, wherein the dosage amount corresponds to 6 to 9 units per kilogram of the total body weight of the subject to be administered to an individual gastrocnemius muscle of the subject or wherein the dosage amount corresponds to 4 to 6 units per kilogram of the total body weight of the subject to be administered to an individual soleus muscle of the subject.