OR-PR 156 Task 1 Competency 3 Lay Out the AFO for Fabrication

Objective  Supplied with a full leg tracing and a completed orthometry form you will create a “blueprint” to be used when fabricating the metal AFO

Correct Ankle Dimensions  Identify and mark the apices of the medial and lateral malleoli  Lay out a line passing through the marks  Measure the width of the tracing between marks and mark midpoint

Correct Ankle Dimensions  Measure out ½ the measured M-L from the orthometry form from the center and mark ½ measured M-L

Correct Ankle Dimensions  Redraw ankle region, blending in with original tracing

Correct Ankle Dimensions  Measure medially from medial malleolus 1 1/4 ” and mark 1 ¼”

Correct Knee Dimensions  Find approximate knee joint center and draw horizontal line

Correct Knee Dimensions  Determine midpoint of tracing  Measure out ½ the measured M-L from the orthometry form from the center and mark

Correct Knee Dimensions  Redraw knee region, blending in with original tracing

Correct Knee Dimensions  Measure medially from medial knee 5/8 ” and mark 5/8”

Determine Mid-Saggital Line  Draw a line beginning at the perineum and passing through the knee and ankle marks

Determine Mid-Saggital Line  Genu Valgum is indicated if the line passes through the knee mark but outside the ankle mark

Determine Mid-Saggital Line  Genu Varum is indicated if the line passes outside the knee mark and through the ankle mark

Lower Section Heights and Locations 1.Heel base 2.Shoe thickness 3.Ankle joint axis 4.Fibular head 5.1 ½”below fib. head (prox. edge of calf band) 6.1 ½” below mark #5 (distal edge of calf band)

Calf Band and Joint Axes  Project lines perpendicular to the mid-saggital line across the tracing for the : Shoe thickness at heel Ankle joint axis Proximal calf band Distal calf band

Ankle Joints and Stirrup  Project a line perpendicular to ankle axis from center of tracing down to heel thickness line  Measure out ½ the measured M-L from the orthometry form on either side of the center and mark Ankle Axis ½ measured M-L

Ankle Joints and Stirrup  Measure out 1/4” medially and 3/16” laterally from previous marks to create minimum clearance  Measure out another 1/8” on each side to compensate for ankle joint thickness  Project lines perpendicular to ankle axis extending from 2” superior to axis down to heel thickness line. The stirrup will be shaped along these lines Ankle Axis 3/16” 1/4” 1/8”

Calf Band Widths  Measure the width of the tracing along calf band lines and mark midpoints  Measure out ½ the measured M-L s from the orthometry form from the centers and mark

Calf Band Widths  Measure out and mark 1/8” from established M- L to accommodate padding  Measure out and mark an additional 1/8” to accommodate band thickness  Connect the outer marks proximally to distally. The band will be contoured to the inside of these lines

Completed Tracing  Connect the M&L distal calf band to the stirrup lines by following the outline of the tracing. The uprights will be shaped along these lines.

Ankle Joints and Stirrup  Variations of alignment for fixed foot and ankle deformity must be accommodated for in layout and fabrication. The orthometry form will inform you of any fixed condition. Follow this procedure if a fixed ankle deformity is present Ankle Axis

Ankle Joints and Stirrup  Find the center of the tracing at the widest point of the calcaneous and mark  Draw a line parallel to the mid-saggital line from that mark down to the heel base line Ankle Axis

Ankle Joints and Stirrup  Measure and record the distance between the line just drawn and the ankle-joint center line drawn earlier  This measurement will be used later when bending a stirrup to accommodate the deformity Ankle Axis

Reversing Tracing  Reverse the tracing preserving only those lines and marks that will be used for the actual fabrication  Your completed tracing is now ready to be used in your fabrication of the AFO END