Analysis of stress fractures in athletes based on our clinical experience

Table 4 Stress fractures in middle and long distance female runners

	Case 1	Case 2	Case 3	Case 4
Age (yr)	19	22	22	20
Body mass index (kg/m2)	18.2	17.5	17.7	17.7
Menstruation status	Amenorrhea	Amenorrhea	Amenorrhea	Amenorrhea
Estradiol1 (pg/mL)	32	36	< 20	21
Bone mineral density (Z score, %)
Lumbar spine	72	81	91	81
Femoral neck			102	92
Stress fracture
Number of fracture	4	2	3	2
Fracture site	R. Metatarsus	Bil. Tibia	L. Metatarsus	R. Calcaneus
	R. Metatarsus		L. Calcaneus	L. Pubic bone
	Bil. Femur		8th thoracic spine

¹< 35 pg/mL in postmenopausal women. R: Right; L: Left; Bil: Bilateral.