1. It is important that the splint not prevent full knee flexion. Do not overtighten the straps--a finger should be able to slide between skin or dressing and strap pad.
2. Measure the length of the calf: Measure the posterior calf with the leg extended. Measure from the base of heel to the crease behind knee (popliteal space) for most accurate fitting.
3. Foot size: The toes should not hang over the splint.

PFS item #'s, sizes and specifications:

• 100 Xlg: 20-23+ inches base of heel to popliteal space.
  Fits a very tall person 6'1½" or taller and accommodates for feet size 13.
• 001 Lg: 18-20 inches base of heel to popliteal space.
  Fits a person approximately 5'10" - ~6'1" with average size feet (10-12.5).
• 002 Med: 16-18 inches base of heel to popliteal space.
  Fits a person 5'5" - 5'9" with average size feet (7-9.5).
• 003 Sm: 14-16 inches base of heel to popliteal space.
  Fits a person 5'0" - ~5'4" with average size feet (5-6.5 or7M).
• 004 Youth: 12½-14 inches base of heel to popliteal space.
  Fits a person who is 3'5"-5'0" tall with feet size 3.5-6.5
• 005 Child: 9-12 inches base of heel to popliteal space.
  Fits an average 4 to 7 year old child with feet size 3.5-6.5.
• 006 Toddler: 5-8 inches base of heel to popliteal space.
  Fits a toddler-preschool age child with feet size 10.5-3.