Anatomy of a shoe
A.Toe box: part of the shoe that covers the toes
B.Vamp: part of the upper that covers the instep
C.Counter: selection of the shoe anterior to the heel
D.Tongue: piece that covers the dorsum of the foot
E.Throat: section where the tongue meets the vamp
Shoes and shoe modification
.Depicts a cross-section of the shoe:
A.Insole : layer of sole closest to the foot
B.Midsole: layer directly below the insole that adds extra support , stability and comfort to the shoe ( not all shoe have a midsole)
C.Outsole: bottommost part of the sole that comes into contact with the ground
D.Shank :bridge between the heel and the ball area of the shoe ;the shank portion of the shoe may be reinforced with a steel shank , a strip of spring steel between the outsole and insole
Foot orthosis
Component of the foot orthosis
.The medial longitudinal arch support is one of the most important aspect of foot orthosis .the support lies under the medial aspects of the foot , extending from the calcaneous to a point just proximal to the head of the first metatarsal . Its purpose is to prevent excessive pronation of the foot by providing external support to the medial longitudinal arch . Support of this arch decrease stress on all the supporting structures of the medial arch.
.The metatarsal pad is a common addition to the foot orthosis .this support starts at a point close to the center of the plantar surface and extends just proximal to the metatarsal head . The pad supports the transverse arch of the foot ; the width usually extends from the first to the fifth metatarsal and narrows toward the proximal end of the support . This pad is primarily used to decrease the pressure from under the metatarsal heads by shifting the weight onto the shaft of the metatarsal.
Foot orthosis
.Wedge and posts :that span the entire length or cover only particular sections can be added to the bottom of the orthosis . These additions are prescribed to compensate for rigid varus or valgus deformities of the hindfoot and forefoot or to provide some resistance to flexible varus or valgus tendencies in the forefoot and hindfoot . In the case of severe pronation , if the medial arch support can not be tolerated , a full-length medial wedge can be added to invert the structures and compression of the lateral structures surrounding the ankle
Ankle-Foot Orthosis
.All orthotic devices , including AFOs must achieve one or more fundamental goals, such as 1) control of motion (2) correction of deformity ,and (3) compensation for weakness .
. Control of motion : a rigid , plastic AFO with the ankle locked in slight dorsiflexion . A floor reaction AFO because the extended , rigid forefoot section accentuates the knee extension moment at Midstance
Ankle-Foot Orthosis
.Correction of more rigid deformities is feasible only in selected cases where the cause is short term and primarily soft tissue related. For example a AFO designed to allow ambulation as well as to help reduce the plantarflexion contractures caused by a hypertonic gastrocnemius following a traumatic brain injury . Many other pathologies that result in spastic contractures can present a similar biomechanical challenge.
Ankle-Foot Orthosis
Sometimes , orthoses are prescribed to offer an additional function : partial axial unweighting of more distal limb segments. Such devices can be used to protect hindfoot fractures and similar pathologies.
Knee-ankle-foot orthosis
.The most common justification for a KAFO is the need for direct control of the knee complex that can not be accomplished in another fashion .
.The development of a number of stance control knee joints suitable for use in orthosis has eliminated several of the major drawbacks associated with locking the knee throughout the gait .stance control orthoses permit many individuals with significant knee paresis or paralysis to walk safely because the knee is mechanically stabilized during weight bearing but is free to flex during swing phase
Hip-knee-ankle-foot orthoses
.HKAFOs are selectively recommended for adult with bilateral paralysis from spinal cord injuries , who tend to abandon more involved orthoses after the first year because of the tremendous energy required to ambulate despite bilateral paralysis .
.One of the most common HKAFOs uses a mechanical linkage to couple flexion of one hip with extension of the other, which permits a reciprocal step-over-step gait. Colloquially referred to as Reciprocal Gait Orthosis(R.G.O) , these HKAFOs are used for a variety of pathologies that result in paraplegia , including spinal cord injury and myelodysplasia.
Orthosis in total joint replacement
.Management of posterior dislocations of hip joint :
.The hip orthosis used to treat a hip that dislocates in a posterior direction is generally proximal to the knee . A laterally placed , adjustable range of motion hip joint capable of controlling flexion , extension , abduction and adduction attaches to a snug-fitting thigh cuff that holds the hip in 10 to 20 degrees of abduction and allows 0 to 70 degrees of flexion. Another study recommends that the hip be held in 0 to 10 degrees of flexion , externally rotated , and abducted 15 to 20 degrees for posterior dislocation.
Orthosis in total joint replacement
Management of anterior dislocations :
.Extension range is blocked at 40 degrees, and the flexion range is generally safe up to 70 degrees , unlike posterior dislocation where flexion is one component of dislocation . To provide rotational control , a knee-ankle-foot orthosis (KAFO) rather than a simple thigh cuff is suspended from the pelvic band.
Orthoses after knee replacement
Orthotic support is used infrequently after total knee replacement except in cases of surgical complications, inadequate bone integrity , or poor recovery after the surgery . The primary indications for orthotic management include weakness or injury to the extensor mechanism ( i.e., evulsion of the patellar tendon ), insufficiency of the medial collateral ligament , and loss of knee flexion or extension range of motion . In very complicated surgeries , salvage procedures for total knee arthroplasty , usually require orthotic treatment as part of postoperative management.
Orthoses after knee replacement
.Occasionally restriction of motion in either extension or flexion range occurs. Preexisting range limitation can complicate surgical recovery , and therapy often is required during the recovery period to improve functional range of motion . A knee orthosis designed to provide dynamic motion can be used to increase the range , maintain therapeutic gains , and improve function and stability .
Knee orthoses for sport-related disorders
Functional braces :
.The majority of functional knee braces are designed to protect p patient with an ACL –deficient knee or to protect the ACL-reconstructed graft while returning to full activity.
.Current research:
.Wojtys et al .compared patients with ACL- deficient knees in braced and unbraced conditions and found a 28% to 84% reduction in anterior tibial translation in brace individuals. Without clinical support , authors have recommended functional bracing for sport participation until ACL reconstruction can be performed,
Knee orthoses for sport-related disorders
Rehabilitative knee braces :
.Individual with ligamentous injuries of the knee, including ACL ,PCL, and MCL injuries , are managed with a variety of nonsurgical and surgical options . Knee braces have been used in each of these setting to facilitate return to play.
.The goal of a rehabilitative brace is twofold: (1) to prevent excessive loads on the damaged or reconstructed ligament and (2) to allow early return to activity.
Congenital and acquired disorders
Clubfoot:
.Various orthoses are used for treatment of clubfoot. Most often , the ortosis is used as a holding device after correction by nonoperative or surgical methods.
.Straight last and reverse last shoes are the most commonly used orthosis for treatment of clubfoot.
Clubfoot
.Denis Brown : typically the devices are adjusted to keep the feet externally rotated , augmenting the forefoot abducted forces provided by the shoes and adding a external rotation stretching force at the ankle . The length of the bar should approximate the width of the child’s pelvis.
Congenital and acquired disorders
Flexible flatfoot:
.The custom-molded University of California Biomechanics Laboratory (UCBL) orthosis incorporates a sustentaculum tali mold to directly resist collapse through the subtalar joint and a heel cup to control hindfoot valgus. This orthosis ectends distally beneath the metatarsals , so support for the transverse metatarsal arch can be added.
Cavus:
.The usefulness of orthoses is limited to accommodation of the deformity for relief of pain and protection of the soft tissues. Symptoms due to abnormal pressure may be relieved by use of an arch support or metatarsal pad.
Congenital and acquired disorders
Bowleg and knock-knee :
.Long leg brace( KAFO) with unilateral bar and applying pressure wit straps
Tibia vara ( blount disease):
.Bracing aims to provide a force at the medial side of the proximal thigh and medial malleolus with an opposing lateral support at the knee.
Pediatric hip orthoses
Pavlik harness:
.pavlik harness has two shoulder straps that cross in back and are secured to a wide chest strap. The anterior straps should maintain the hips in 90 to 110 degrees of flexion. The straps should be tensioned to maintain 20 to 30 degree of abduction only , with the remaining abduction arising from gradual relaxation of the adductors.
Ilfeld orthosis:
.The Ilfeld orthosis is a passive positioning device that holds the hips in abduction but does not create significant hip flexion . For this reason , it is more effective as a postoperative abduction device than for treatment of infantile hip dysplasia or dislocation. It consist of two thigh cuffs attached to an adjustable crossbar . This construct is attached to a waist strap to maintain position .
Pediatric hip orthoses
Legg-calve-perthes disease:
.Multiple orthoses have been designed to hold the hip in abduction and to permit varying degrees of internal rotation and /or flexion , thus directing the head into the acetabulum.
Atlanta Scottish Rite orthosis:
.compared to the Toronto and Newington orthoses , the Atlanta Scottish Rite orthosis probably is the only device still in widespread use , typically for postoperative purpose rather than for nonsurgical containment. It occasionally used as an ambulatory abduction device in children with DDH. The original orthosis had two thigh cuffs separated by an abduction bar.
Atlanta Scottish Rite orthosis