Fitting Instructions

1. Place patient’s foot on the footplate* and adjust the height of the anterior shell so that it covers the tibial tubercle but does not impinge on the patella at full knee extension. Trim and/or heat mold the anterior shell as needed for optimal patient comfort.*Please note: This is not a full-foot footplate. The patient’s heel will clear the posterior of the footplate. This is expected. The orthotic will accommodate the heel.
2. Place the orthotic (either the shoe’s, an off-the-shelf, or a custom one) on top of the footplate and insert into the shoe. Do not affix the orthotic to the footplate at this time. See Modification to Footplate for further details.
3. Place the patient’s foot into the shoe on top of the orthotic.
4. Fasten proximal straps only.
5. Check for pressures, and slide strut lateral, posterior or anterior as needed to optimize fit.
6. With patient weight bearing, open lateral side of shoe and mark reference for final assembly.
7. Remove Matrix or Matrix MAX and lightly bond the orthotic to the footplate. Do not permanently bond the orthotic at this time.
8. Perform trial walking and gait assessment. Check that the orthosis is giving the correct ground reaction at the knee. If Matrix or Matrix MAX is hyperextending the knee, then the heel on the footwear is too low and the addition of a heel post is needed. If there is knee flexion at mid-stance, then the heel should be reduced. See Shoe Selection.
9. It is important to check that Matrix or Matrix MAX is comfortable and not causing areas of pressure concentration that may lead to blistering or pressure sores. Particular attention should be paid to the following boney prominences: head of fibula, patella, lateral malleolus, 1st and 5th metatarsal heads, and base of 5th metatarsal.

Shoe Selection

Shoe selection is critical to the performance of Matrix and Matrix MAX. The following points should be adhered to when selecting footwear:

• Heel pitch should be 1.5 cm (5/8”). This gives a neutral ground reaction effect at the knee.
• Firm supportive heel counter for rear foot control.
• Non-slip sole that is not too rigid to allow the footplate to flex and propel at toe off.
• The patient should be instructed to only wear shoes that have a similar heel pitch to the ones used in the initial assessment and gait analysis. Any deviation from this may give ground reactions that are detrimental to the knee joint.
   

Modification to Shoe Plate

• The footplate may be ground, as needed.
• For heel posting, the posting should be added to the upper surface of the footplate.
• Valgus and metatarsal pads may be added to improve comfort and accommodate prominent metatarsal heads.
• Proximal or mid-transmetatarsal amputations can be accommodated by the addition of a total contact foot bed and toe filler.