Orthoses, splints and casts

6 Orthoses, splints and casts Paul T. Charlton and Duncan W. N. Ferguson Introduction As defined by the International Standards Organi- zation, ‘An orthosis is an external device used to modify the structural or functional characteristics of the neuromuscular system’. This definition encom- passes all other devices referred to as splints, braces and casts. Although not so well defined, it is com- mon practice for clinicians to refer to orthoses as those external devices provided byanorthotist, while splints are commonly recognized as orthoses made of low-temperature plastics or fabric by therapists other than orthotists. Nonremovable orthoses made of plaster or casting tape are referred to as casts. The use of orthoses (in all their forms) for adults presenting with spasticity has been controversial (ACPIN, 1988), and use varies from centre to cen- tre depending on the treatment regime used by the therapist. However, in pediatrics, their use is more widely accepted, partially due to the work of Mead- ows (1984) in the early 1980s and those therapists using the Conductive Education techniques pro- moted by the Peto Institute. In adult neurology, treatment is often based on the Bobath concept of normal movement (Bobath, 1980), which for many years frowned on the use of splintingbecauseoftheobviousimpingementonthe ability to perform normal movement. Normal movement is the ultimate goal in neuro- rehabilitation. However, to expect all patients with a neurological deficit to make a full recovery is not realistic. It must be accepted that, despite our best efforts, at some stage recovery will plateau and the remaining deficit may require mechanical manage- ment to allow the person optimum function. This factor must be a consideration when the need for an orthosis is assessed and highlights the need for reg- ular review, at which time thought can be given to the true aim of intervention: rehabilitation or man- agement. It is now generally accepted that there can be a place for orthoses following proper assessment and selection. The aim of orthotic intervention should be, where it is achievable, to realign the limb segments as near as possible to the normal position in the hope that normal posture will occur through recruitment of the appropriate muscle groups. It should also be recog- nized that orthotic intervention is only one of the options in neurological rehabilitation and that the aims of treatment and intervention must fit with those of the rest of the multidisciplinary team, com- munication with whom is another vital part of the assessment. It is this understanding that is crucial to correct orthotic assessment and provision. It should be recognized that while most orthoses are designed for their biomechanical effect, there is always a sensory element to their use. It may be that some simple orthoses change movement or presentation on that basis. There is considerable ongoing work on the effect and mechanism of Lycra orthoses, with some centres using them widely as full body suits or specific limb garments for various presentations. At present the mechanism and crite- ria on how these work and could be used is unclear, but use continues with some claiming considerable success. 113 114 Paul T. Charlton and Duncan W. N. Ferguson Orthotic aims The fundamental aim of providing an orthosis may be to help and improve recovery or to manage remaining deficits. Often there are choices in how to intervene, depending on the prognosis, potential for change and input of other therapies. Where pro- vision of an orthosis is part of the treatment regime, it should be recognized that one device may not pro- vide for the patient’s requirements throughout their rehabilitation and, as with other interventions, its use will require monitoring and adjusting as changes occur. Theaimofanyorthosisshouldbeclearlyidentified at the assessment stage. The most common aims are outlined below. Reduce or inhibit an abnormal pattern by positioning Holding an ankle in slight dorsiflexion can inhibit the onset of an extensor pattern and is often achieved by the use of an ankle-foot orthosis (AFO). Gross trunk extension can be managed byholding the hip in flex- ion and inducing a lumbar lordosis, as with special seatingor a sittingbrace oftenused in children.These devices must be sufficiently rigid to prevent move- ment beyond the desired position. Another example is the use of dynamic insolesand AFOs to reduce tone as described by Hylton (Hylton & Allan, 1997). Prevent abnormal movement By splinting in a position of maximum function with a rigid device even if the spasticity can not be inhib- ited then the abnormal movement caused by it may be prevented. This should be undertaken with care, as the forces generated can be considerable. Promote normal alignment and movement In many patients it is possible to fine-tune the posi- tioning in either sitting or standing such that the alignmentof thebody segments isas close aspossible G.R.F. G.R.F. Figure 6.1. Line of ground reaction force and ankle in normal subject compared to one with a hyperextended knee. to the recognized normal. In standing, this can be achieved with some accuracy with the use of gait analysis, which allows alignment with reference to the ground reaction force (Stallard, 1987). The effect of this is to place the body in optimum position to recruit normal movement and prevent compen- satory movements. The most common example of this is the hemiplegic patient with an extensor pat- tern who typically presents with a plantar-flexed ankle, hyperextended knee and flexed hip and trunk. By fixing the ankle in slight dorsiflexion, it is possi- ble to push the knee anteriorly, which then encour- ages the patient to extend the hip and trunk to main- tain balance. Ideally a force platform with ground reaction force visualization is used and the ankle angle is altered until the ground reaction force is just posterior to the knee centre (Stallard, 1987) (Fig. 6.1). This is a well-documented technique with cere- bral palsy children but is equally effective with hemi- plegic adults (Butler et al., 1997). Preventing contractures and maintaining or increasing joint ranges There is now evidence that contractures are a common sequel to neurological damage, and the Orthoses, splints and casts 115 F1 F3 F2 Figure 6.2. Correction of a plantar-flexed ankle and the forces (F1, F2, F3) applied. importance of prevention is recognized. A greater understanding of the response of muscle to changes in length and position has led to improved orthotic management. However, there is much to understand about the role of orthoses forthe prevention or allevi- ation of contractures. For example, we do not know how long the device needs to be in place during a 24-hour period in order to be effective. Targeted motor learning Butler and Major (1992) have strong evidence to suggest that an effective method of learning is to immobilize joints caudally until sufficient control is gained proximally and then removing support at the next level until control is gained there. This is mainly geared towards the cerebral palsy child and starts with head control and works down each spinal level. The same logic is applicable to the lower limbs. It is difficult to work on improving hip control if there is little control of the knee supporting it. There is increasing recognition and understanding of the influence of mechanical alignment on postural mus- cle recruitment and postural tone (Shumway-Cook, 2001). Biomechanics and materials A good understanding of this subject is essential to appreciate fully the forces involved and their influ- ence on the design of orthoses. Those interested may find the ‘Further Reading’ list at the end of this chap- ter useful. Any external device must provide force to have an effect, and an important consideration of applying an orthosis is how and where to apply these forces and make them as tolerable and effective as possible. One of the main skills of the orthotist is to identify, minimize and optimize the forcesand pressures gen- erated at the patient orthosis interface. To do this, knowledge of basic mechanics is important. In par- ticular, it is useful to note that most orthoses use the application of a set of three forces to produce the required effect; this is usefully illustrated by consid- ering the correction of a plantar-flexed ankle. To correct a flaccid foot (Fig. 6.2) would merely require the application of a force under the forefoot. However, if the patients’ ankle were tight or demon- strating clonus, then the orthotist should place one hand over the top of the ankle and one hand would be positioned to provide a better push on the base. If 116 Paul T. Charlton and Duncan W. N. Ferguson 450 N 200 N 190 N 100 N 250 N 90 N Figure 6.3. Forces applied to control a hyperextending knee and the effect of increasing lever length. the foot is very tight or there is a strong extensor pat- tern, then there is a danger that you might push hard enough to tip the whole patient backwards. This is because it is possible to overcome the frictional force of the patient on the chair as indicated by force. An indication of how mechanics can influence orthotic design is shown in the diagrams depicting the forces involved in correcting a hyperextended knee. It can be clearly seen how an increase in the overall length of the orthosis can lead to reductions in the applied forces, since the turning effect (moment) applied at the knee is determined by both the magnitude of the forces and the distance between them (Fig. 6.3). It is for this reason that a Swedish knee brace is likely to be uncomfortable and a long leg device may be the only practicalorthotic solution for quadriceps spasticity. The ability of an orthosis to manage spasticity will depend on how the spasticity presents. There is a need to be aware of any counter forces, which may have pressure and skin care repercussions. The abil- ity of the patient to tolerate the required forces nec- essary to achieve the aim of the device is of ultimate importance. It may be that, at review, a decision is made that the forces required areintolerable. In such a case the patient may be considered for other forms ofspasticity management such as injection, pharma- ceutical or surgical intervention as well as or instead of the orthosis. Plastic or metal orthosis? While it is not within the remit of this chapter to explore the varieties and limitations of available Figure 6.4. Distortion of a shoe with metal ankle-foot orthosis and T-strap by plantar flexion. materials, it is worth explaining a commonly asked question. Itis often assumed that because metal is a stronger material, that metal orthoses are stronger and there- fore more effective than plastic orthoses at with- standing high forces. In fact, often the opposite is true because of the method by which the orthoses acts upon the limb. The benefit of the plastic ortho- sis is that it can be moulded to the patient and so apply loads in precisely determined positions and frequently over a large area. The metal orthosis, on the other hand, usually depends on the patient’s shoe being an integralpart of the orthosis. This may lead to failures both in the fixing of the orthosis to the shoe (the socket) and the shoe itself deforming. It may also depend on some of the forces being applied by leather straps under the influence of the patient or carer. Metal orthoses are undoubtedly heavier than plastic orthoses, but often the weight is as much due to the shoe socket as the calliper itself. In addi- tion, the shoe may require reinforcing to prevent dis- tortion from the forces applied which may further increase weight (Fig. 6.4). Orthoses, splints and casts 117 Obviously any increase in weight is a disadvantage especially where there is a combination of weakness and spasticity as, for example, in multiple sclerosis. Assessment An orthotic assessment should ideally be performed by an orthotist and the treating therapist prefer- ably with experience in orthotics. The team should then explore the history, current treatment and likely prognosis in order to define the aims of the orthosis. Consideration of the prognosis is important and will help determine the practicality of an aggres- sive approach. For example, a young patient 6 weeks poststroke presenting with a hemiplegia would hopefully recover sufficient motor control to attain a reasonable gait. The orthotic aim in such a case may well be to provide realignment to a degree that may challengestability to ensurethat compensatory posi- tions are not recruited in favour of ‘normal’ activity, as it becomes available. In practise this maybe a rigid AFO set in dorsiflexion to prevent knee hyperexten- sion, even if tone in the quadriceps is not quite suffi- cient tomaintain stability for any length of time.In an older patient, several years poststroke, the orthotic aim may well be purely to maintain stability or pre- vent pain. Understanding is increasing of how orthoses can help to manage ground reaction force through- out the gait cycle and provide dynamic stretch at both calf and hip towards terminal stance by use of a rigid AFO. Meadows (2004) and Owens (2004) have demonstrated in detail how this can be further enhanced by shoe design and modification. Itisworth notingthat,depending on resources and the patient and therapist commitment, it is some- times possible to change and improve quite estab- lished gait patterns (Butleret al., 1997; Baker & Charl- ton, 2004). It is in these instances that the simulation of the effect of an orthosis, before proceeding to a definitive one, is extremely useful and gives some indication as to the possible outcome. When examining the patient, consideration should be given to joint range, muscle tone in rest and during activity, forcerequired holding aposition, Figure 6.5. Lower extremity telescopic orthosis (LETHOR) for assessment or treatment. skin condition, sensory loss and oedema. If the use of a device seems a possibility, consideration should be given to the effect on other joints, the patient’s function and the need for other intervention such as spasticity management, stretching regimeor physio- therapy for gait re-education prior to or after supply. To assist in making these decisions, it is extremely useful to simulate the effect of the orthosis either by bandaging the limb in the desired position or by adapting an existing orthosis. Even a brief glimpse as to how the patient may perform in a definitive orthosis will avoid unnecessary work. Prediction of functional effect is difficult without such a trial. Assessment tools may be stock orthoses or discarded bespoke orthoses. In particular, it is useful to have an assessment knee-ankle-foot orthosis which may allow the patient to experience full knee extension (Fig. 6.5). The opportunity to apply a firm dorsiflexion ban- dage is also useful to simulate the effect of an AFO to limit plantarflexion. Common findings during assessment include: 118 Paul T. Charlton and Duncan W. N. Ferguson r Weak hip flexors when the initial assumption was that lack of ankledorsiflexion wasthe cause of poor foot clearance. r Quiet zones. It is not uncommon with diplegic cerebral palsy children and some poststroke hemi- plegic people with extensor tone to find a range of ankle dorsiflexion where the spasticity can not be induced. In such patients the orthosis is made to limit movement to within that quiet zone (Meadows, 1984). r Rigidity. Theforce can be sostrong that it cannotbe opposed tolerably and orthotic management may be limited to accommodation and stability. r ‘Positive support’ is a term commonly used by physiotherapists to describe the onset of spastic- ity in response to loading the foot. In such cases a dynamic insole can be used to accommodate the contours and dynamic arches of the foot to help this settle, this can be incorporated into an AFO (Small, 1995). r It is our experience that a mechanism exists whereby a patient will tend towards an abnormal pattern of either flexion or extension in antici- pation of having to bear weight on the side over which he or she does not have full control. This confidence factor, we believe, is demonstrated by patients who present with an abnormal pattern yet can improve considerably by the provision of a relatively simple device such as an ankle stirrup. We know that the ankle stirrup does not apply the appropriate forces to control the limb but believe that because it gives the wearer greater confidence, he or she does not recruit the abnormal activity in trying to improve stability. r Shunting has been described as the situation where the control of spasticity at one joint leads to its increase at another, usually the next, joint (Edwards, 1998). Thisis commonlyseen inpatients with spastic diplegia where the control of ankle position may result in increased knee flexion or internal hip rotation. In such a case, orthotic inter- vention may be contraindicated. r Severe spasticity can often generatesufficient force either to overcome the orthosis or to endanger tis- sue breakdown at the patient orthosis interface. If orthoses are used, this can be in conjunction with botulinum toxin injections which can reduce the force generated. Even with other management techniques it is often accepted that the orthosis will not fully correct the affected joint; for instance, with the invertingankle theorthosis is used to min- imize damage to the joint. Because of the dangers of pressure, it is common to use the more tolerable correction of a padded leather T strap and metal AFO than the less forgiving correction of a close- fitting plastic orthosis. The added benefit of the metal AFO and T strap is that the degree of correc- tion can be controlled by the length and tension of the strap. There are those who would argue that with severe spasticity, the presence of an orthosis encourages the muscle to pull against it and there- fore reinforce the pattern, although there appears to be little evidence to support this. r Assessment can also give the orthotist an idea of the forces involved and thus help to determine the type of orthoses required. Once a specific presentationhas been identifiedthen it is worth exploring the underlying cause. An exam- ple of this is knee hyperextension, a common pre- sentation in hemiplegia. The underlying mechanical cause of this can be: r Inability to get the heel to the ground due to tight- ness of the tendo Achilles tendon r Hamstring weakness r Quadriceps weakness r Quadriceps spasticity r Weak hip extensors The simplest method of preventing knee hyperex- tension is the Swedish knee brace, which, although not an effective definitive orthosis, is a very effective assessment tool. Often when the knee is controlled, ankle control is lost and it becomes apparent that the knee is a secondary problem to lack of range or control at the ankle. There is also benefit in using this orthosis as a therapy tool as by preventing knee hyperextension then a far more effective stretch of the tendon Achilles is achieved on weight bearing (Fig. 6.6). A successful assessment does not necessarily result in the supply of an orthosis, although often Orthoses, splints and casts 119 (b)(a) Figure 6.6. Use of a Swedish knee brace to prevent hyperextension and increase stretch on Achilles tendon. the process of assessment will have other benefits, such as highlighting and clarifying where problems lie and consequently where treatment can be more specifically targeted. Having identified deficits in motor control, joint range and other physical factors, it is important to assess sensory and perceptualloss. We can nowmake a decision on the aims and objectives of the ortho- sis and identify which orthosis to provide. This deci- sion may be influenced by a number of factors such as oedema, sensation, pressure tolerance or patient acceptance. If the aim involves using the orthosis unsupervised on a daily basis, it is essential that individual accep- tance is fully addressed. If the person refuses to wear the orthosis, then supply is pointless. Acceptance is helped greatly if the patient or carer is made fully awareof theaims ofthe orthosis,shown the potential benefits and warned, at an early stage, of any practi- cal implications such as difficulty with footwear. As with so many otherforms of treatment, the final prescription may well be a compromise between the ideal, the practical andthe acceptable.The most suc- cessfulprescription is that whichhas been made with the full involvement of the person and his or her carers. Casting Thereare several advantages of the use of castingver- sus providing a definitive orthoses, such as cost and 120 Paul T. Charlton and Duncan W. N. Ferguson availability. In addition, the freedom to change the position easily and accurately and the fact that the cast may not be removable means that the limb has time to settle and accommodate to its new position. This will hopefully make the joint more amenable to a further stretch to a new position. By totally encasing the limb, any corrective forces are spread over a maximum area, therefore reducing pressure. Consequently serial casting has been found to be extremely effective in stretching out contractures (Zander & Healy, 1992), often with the final cast being bivalved and used as a removable splint to maintain the new range acquired. When a spastic limb has been enclosed in a cast, it will often be found less active and therefore more likely to tol- erate an orthosis. Full-length leg plaster back slabs are now commonly applied to the early neurological insult. This will minimize knee flexion and hamstring contraction but also allow for early weight bear- ing, which will give effective stretch to the Achilles tendon. The use of plasters is also a useful prelude to a definitive orthosis, both for early application and for assessment. The development of modern cast- ing materials and the availability of casting courses for therapists have meant that the ability to apply good casting technique is accessible in most hospi- tals and centres. Itis still essential that skill be used to ensure a smooth patient–cast interface and that the distally exposed limb be monitored for any signs of problems beneath the plaster, such as swelling, dis- coloration or temperature changes, which may indi- cate pressure problems and necessitate cast removal. Clear guidelines exist for the application of casts, and it is important that these be adhered to (ACPIN, 1998). Timing of orthotic intervention In order to minimize contractures, it is generally rec- ognized that early aggressive intervention is essen- tial. However, the timing of intervention for reha- bilitation of normal movement is not quite so well defined. Common sense may dictate that the earlier the patient can experience ‘normal’ positioning and alignment the better, although evidence for early intervention is lacking. It is important that opti- mum footposition and alignment be achieved before attempts aremade to achieve free standing and walk- ing. It is undesirable to teach normal hip and knee movement when there is insufficient ankle dorsiflex- ion to attain heel strike. This is practically impossi- ble for the patient, as without adopting some form of compensatory strategy, there is a risk of tripping over the slightest obstacle. Failure to use an orthosis in this situation will lead to a higher energy cost or an unsafe gait. When to wear an orthosis This will dependon the aim of theorthosis and needs of the patient. An orthosis, if designed to realign the skeleton in a patient early in their rehabilitation, may require more motor control than the patient is capa- ble of, and the aim may be to use the orthosis only within therapy to work on developing recruitment. Patients progressing in their rehabilitation may be able to demonstrate good control without an ortho- sis when they are concentrating in a controlled envi- ronment, but they may lose that ability in performing functional tasks elsewhere. In this case the orthosis may be worn between therapy sessions but removed for therapy to try and develop independent con- trol. Some patients demonstrate good control most of the time but may lose control and alignment when fatigued as in the case of many MS patients. These patients oftenuse an orthosis selectivelywhen they wish to walk longer distances or when they anticipate problems with their mobility. This should be considered and discussed at the assessment stage. Orthotics in paediatric management As one mightexpect, thereare special considerations in dealing with children with spasticity. The absence of normal muscle tone on an immature skeleton can lead to considerable complications. Around the Orthoses, splints and casts 121 hip joint, for example, it is believed that spasticity can lead to malformation of the acetabulum and recurrent or permanent dislocation. A dislocated hip, as well as causing pain, can lead to problems with seating and secondary spinal scoliosis. It is not uncommon for major orthopaedic intervention to be required to resolve these problems. Orthotic intervention can help as positioning hips in maxi- mum abduction ensures maximum containment of the femoral head and optimizes development of the acetabulum. Types of orthoses Classification A system has been developed whereby orthoses are classified and named by reference to the parts of the body over which they pass (Harris, 1973). For exam- ple, an orthosis around the ankle is called an ankle- AFOand a full leg calliper is termed a knee-ankle-foot orthosis (KAFO). This classification is usefulbut does not describe the function, construction or aim of the orthosis. Footwear and adaptations to shoes An extensor pattern of the lower limb is often accom- panied by spasticity in the toe flexors. This leads to clawing, causing pain on the tops of the toes from pressure from the shoe and on the tips of the toes from bearing weight on them. This or any pain tends to increase tone and further compound the problems. Fabrication of a silicone orthosis under the toes to lift the tips from the ground can relieve this pain and help reduce overactivity. Patients with mild spasticity may benefit from careful selection of footwear. A common occurrence is overactivity in the ankle inverters and long toe flexors, which presentsas lateral instability ofthe ankle andclawing of the toes. Shoes with a strong heel stiffener but soft deep forepart are frequently sufficient to resolve or manage these problems. Preferably the shoe should have a broad heel to increase stability, but if this is not available, conventional shoes can be modified to have a broader heel and a light tilt can be added to provide further stability. Insoles may be added to conventional shoes to achieve increased stability, an improved base of support, stretch on the plantar fas- cia or redistribution of pressure. The height of heel may be altered to accommodate loss of range of the Achilles tendon and achieve a heel strike and knee alignment. It should be realized, however, that this is atthe expense of stretchingand that, once a heel raise has been used, there may be a loss of range, which cannot be recovered. Tightness of the Achilles ten- don can also lead to a compensatory collapse of the medial arch of the foot. It is common for the midfoot to evert and dorsiflex in order to achieve heel contact with the ground. Ankle-foot orthoses Themost commonly recognizedAFOis probablythat which gives some control to ankle plantar dorsiflex- ion. It should however be recognized that AFOs also include orthoses that control mediolateral move- ment such as the Aircast and Malleolock (Fig. 6.7) as well as various soft orthoses that may offer com- pression or limitations of movement by strapping. AFOs that help the ankle to maintain a dorsiflexed position are not useful in the management of spas- ticity, as the force of the spastic muscle can over- ride it and render it ineffective. Static or limited- motion orthoses include callipers with range-of- movement adjustments, of which there are many types. As mentioned earlier, it is important that the foot be well fixed in the shoe and that the shoe not distort. While it is common to use the high- strength resilient material Ortholen for many AFOs, this is to be avoided with spasticity, where rigidity is essential. Yates (1968) examined the concept of the AFO made of polypropylene, and some fundamental flaws were noted when it was applied to spasticity management. The AFOs were contoured to allow for the shoe pitch, which placed the ankle in a plantar- flexed position. As the spasticity increased, the cen- tre of gravity moved back and the heel elevated out 122 Paul T. Charlton and Duncan W. N. Ferguson )b()a( Figure 6.7. (a) Aircast ankle stirrup and (b) Malleolock ankle brace. of the orthosis because the shoe was unable to apply sufficient force to hold the foot. This, combined with plantar flexion for the pitch of the shoe, can lead to contracture of the calf muscles. The trim line behind the metatarsal head sometimes simulated a plantar grasp reaction, thus increasing the level of spasticity. Meadows (1984) endorsed the casting of AFOs at 90 degrees with a stretch encouraged on the Achilles tendon from a fitted heel strap, which bisected the foot and leg at 45 degrees (Fig. 6.8). This encourages better control of the hindfoot. The additional use of a sole wedge or rocker made the flow of mobil- ity more fluent from heel strike to toe-off by main- taining a superior leg-over-foot position controlled by the proper application of forces around the knee through the walking cycle. The study went on to show that there was a reduction in tone, the neces- sity for surgery was less and long-termcomplications of scarring and a shortened spastic muscle were diminished. Types of ankle-foot orthoses Dynamic insoles and dynamic ankle-foot orthoses (DAFOs) Much publicity was given to these bythe work of Hyl- ton (Hylton, 1989; Hylton & Allan, 1997), who advo- cated the use of a footplate or insole that was man- ufactured accurately to reinforce all of the dynamic arches of the foot, including the lateral arch (Fig. 6.9). As well as aggressively supporting these arches, she also advocated building up and supporting the toes, other than the great toe. An insole made to this specification cradles the calcaneum and metatarsal heads, providing an optimum weight-bearing sur- face, which is most likely to allow the foot to settle. This footplate was used as a basis for a dynamic AFO, which, unlike other AFOs, extends only just proxi- mal to the malleoli, offering ankle alignment without addressing plantar dorsiflexion. The material used is thin malleable plastic and the aim of the orthosis [...]... Major, 1987) and reciprocal gait orthosis (Douglas & Solomonow, 1987) developed for paraplegics, both require relatively smooth symmetrical hip action and probably preclude all but the mildest of spasticity ‘Twisters’ are functional hip orthoses that control internal rotation during gait; they can be most effective and are most commonly used in children with diplegia Orthoses, splints and casts (a) (b)... stimulated; the current between these electrodes induces activation of that nerve and a subsequent muscle contraction However, this is obviously limited to those nerves and muscles that lie superficially The technique is particularly well tested in the management Orthoses, splints and casts of foot drop (Taylor & Burridge, 1999) and well recorded in use on the upper limb While having an obvious role as an... over the wrist and MCP joints to stretch the spastic flexor groups As with other orthoses, this should be reviewed and alternatives tried if not successful Often these orthoses are made of lowtemperature thermoplastics, which, while easy to 127 128 Paul T Charlton and Duncan W N Ferguson Figure 6.15 Dr Berrhill jacket mould and adjust to achieve an accurate fit, have limited strength and durability For... the shoulder girdle and heavy arm, as described earlier, often benefit from strapping the arm to the body in a way as to distribute its weight evenly and minimize the effect of pulling down An effective orthosis for this is similar to a half jacket, which spreads the load evenly This is sometimes known as a Dr Berrhill jacket (Fig 6.14) The hand and wrist The fine movements of the hand and fingers make it... complexity of these interactions has been Orthoses, splints and casts demonstrated by Price et al (1999) in studying the variations in scapular motion in these patients Orthotic intervention, although common, is not usually satisfactory The biomechanical aim is to reduce subluxation by unloading the shoulder joint by suspending the humerus in a cuff on a figureof-eight bandage about the opposite shoulder However,... a definitive orthosis Hip and hip-knee-ankle-foot orthoses (HKAFOs) Hip orthoses, sometimes known as sitting braces, can assist in postural control to help with windswept, scissoring and sacral sitting positions This may be instead of or along with special seating As mentioned earlier, hip position can play an important part in hip containment and development The more complex orthoses, such as the Parawalker.. .Orthoses, splints and casts Figure 6.9 Dynamic ankle-foot orthosis some restriction to dorsiflexion (e.g those prone to a flexed gait) By providing adjustable plantarflexion, the position can be altered to fine-tune the orthosis Figure 6.8 Polypropylene ankle-foot orthosis with full foot piece and 45-degree ankle strap is to have a tone-reducing effect... for patients and clinicians, and the cause of the problems is not always clear Sometimes it appears to be due mainly to subluxation, while at other times tightness due to spasticity in the rotator cuff is the cause The shoulder is often painful but, in addition, laxity and subluxation makes it prone to injury in handling These problems can be exacerbated if the upper limb is oedematous and heavy, leading... orthopaedic appliances Orthopaedics, 1: 153–62 Zander, C L & Healy, N L (1992) Elbow flexion contractures treated with serial casts and conservative therapy J Hand Surg, 17: 694–7 FURTHER READING Bowker, P., Condie, D N., Bader, D L & Pratt, D J (1993) Biomechanical Basis of Orthotic Management London: Butterworth Heinemann Duncan, W & Mott, D (1983) Foot reflexes and the use of the inhibitive cast Foot Ankle... by extending the orthosis down over the front of the clavicle and under the arm By fastening around the back, this creates a three-point pressure with the 125 126 Paul T Charlton and Duncan W N Ferguson Figure 6.13 2 Becker intelligent knee assessment KAFO back, the back of the head and the front of the clavicle Although this is cumbersome and some may feel impractical, it may have uses for helping with . 6 Orthoses, splints and casts Paul T. Charlton and Duncan W. N. Ferguson Introduction As defined by the International Standards Organi- zation,. malleable plastic and the aim of the orthosis Orthoses, splints and casts 123 Figure 6.8. Polypropylene ankle-foot orthosis with full foot piece and 45-degree