The Modulatory Effect of Female Sex Hormones on Spinal Neuroplasticity

FEMALES

Inclusion Criteria:

* Ages 18-39 years
* Eumenorrheic (regular monthly cycles of 24-35 days)
* Moderately active (less than 7 hours of vigorous physical activity per week)
* History of pregnancy is allowed if patient is in post-lactation phase

Exclusion Criteria:

* History of musculoskeletal or orthopedic injury of the spine, hip, knee, ankle or foot
* History of neurological injury of the peripheral or central nervous system
* Current smoker
* History of disordered eating
* History of stress fracture in the lower limb
* History of a connective tissue disorder (Marfan's syndrome, Ehlers-Danlos disease)
* Pacemaker, metal implants in the head and spine region
* Pregnancy
* On a hormonal contraceptive regimen (oral, transdermal or vaginal)
* History of menstrual dysfunction (primary or secondary amenorrhea, oligomenorrhea, anovulatory cycles, polycystic ovarian disease)
* Started or stopped taking oral contraceptives within the previous 6 months
* Exercise vigorously more than 7 hours per week or currently participating in competitive level sports.

MALES

Inclusion Criteria:

* Ages 18-39
* Moderately active (less than 7 hours of vigorous physical activity per week)

Exclusion Criteria:

* History of musculoskeletal or orthopedic injury of the spine, hip, knee, ankle or foot
* History of neurological injury of the peripheral or central nervous system
* Current smoker
* History of disordered eating
* History of stress fracture in the lower limb
* History of a connective tissue disorder (Marfan's syndrome, Ehlers-Danlos disease)
* Pacemaker, metal implants in the head and spine region