Cremaster muscle :- By vastralphysiotherapyclinic | September 24, 2018 - 12:27 pm |September 25, 2018 Physiotherapy Clinic Leave a comment Cremaster muscle :- Muscle details :- a muscle that covers the testis and the spermatic cord. Origin:- Inguinal ligament . Insertion :- Tunica vaginalis . Nerve supply :- Genital branch of genitofemoral nerve. Actions :- raise and lower the scrotum.