In the account of each muscle, the description of the condition found in most specimens of the Lesser Prairie Chicken (T. pallidicinctus) is given first. This is hereafter referred to as the typical condition for T. pallidicinctus. Then any individual variations found within this species are given. Under the heading T. cupido any constant differences between this species and typical T. pallidicinctus are given first, and any individual variations found within the species T. cupido (both subspecies considered together) are given second. Under the heading P. p. jamesi any constant differences between this subspecies and the typical condition for T. pallidicinctus (thus these differences are not necessarily constant between the two genera) are given first, and any individual variations found within the subspecies P. p. jamesi are given second.
In the bird embryo, according to the studies of Romer (1927) and Wortham (1948), the muscles within each segment of the leg differentiate from distinct dorsal or ventral mesenchymal masses. Presumably these represent the primitive dorsal extensor and ventral flexor muscle masses. The list below indicates the ontogenetic origin of the avian leg muscles, according to the studies of Romer and Wortham. The individual muscles are discussed in the order in which they are listed below.
Dorsal muscles of thigh
| M. extensor iliotibialis lateralis | M. extensor iliofibularis | |
| M. extensor iliotibialis anticus | M. piriformis | |
| M. ambiens | M. gluteus profundus | |
| M. vastus lateralis | M. iliacus | |
| M. vastus medialis | M. iliotrochantericus medius | |
| M. femoritibialis internus | M. psoas |
Ventral muscles of thigh
| M. flexor cruris lateralis | M. adductor superficialis | |
| M. flexor cruris medialis | M. adductor profundus | |
| M. caudofemoralis | M. obturator | |
| M. flexor ischiofemoralis | M. femorocruralis |
Ventral muscles of shank
| M. gastrocnemius | M. flexor perforatus digiti III | |
| M. flexor perforans et perforatus digiti II | M. flexor perforatus digiti II | |
| M. flexor perforans et perforatus digiti III | M. flexor hallucis longus | |
| M. flexor perforatus digiti IV | M. plantaris | |
| M. flexor digitorum longus | ||
| M. popliteus |
Dorsal muscles of shank