Physical and Occupational Therapy
Therapy Methods
Physical therapists and occupational therapists working with children with CP may choose from a variety of therapy methods, including neurodevelopmental therapy, Vojta, Peto, and Rood.
There is, however, no clear scientific evidence to support the superior effectiveness of any one particular approach. Often, therapists will use a combination of these therapeutic methods in association with an emphasis on functionally based therapies. The ideal duration and frequency of therapeutic programs is also not clear. There has been a recent interest in intermittent high-frequency therapy models, but controlled studies have failed to demonstrate any advantage to this approach (67,68).Stretching
Children with CP are at significant risk for contracture formation due to muscle imbalances and static positioning. Contractures can interfere with comfortable positioning, functional activities and care needs, such as dressing, bathing, and toileting. After an initial assessment of baseline range of motion, institution of a daily home exercise program with repetitive stretching exercises is usually recommended, although there is no clear evidence to support its efficacy or provide guidance in regards to the ideal frequency or duration. There is some evidence to suggest that a sustained stretch is preferable to manual stretching (69). Positioning techniques, orthotic devices, splints, and casting are often recommended to provide a more prolonged stretch. Serial casting is a technique where a series of successive casts are applied in the hopes of progressively increasing the range of motion with each cast. It is used most frequently at the ankle joint, often in conjunction with botulinum toxin serotype A (BoNT-A), in order to improve dorsiflexion range of motion. Systematic reviews of the literature reveal little evidence to suggest casting is superior to no casting, primarily due to the lack of randomized controlled trials (70).
The evidence does suggest a short-term effect on improved range of motion (71) and stride length during ambulation (72). Although a number of small randomized controlled trials (RCTs) have compared BoNT-A and casting, there is no strong and consistent evidence that casting, BoNT-A, or the combination of the two is superior to the others (70). Lack of evidence was primarily attributed to methodological limitations of the available studies.Strengthening
Formalized strength testing in ambulatory children with spastic diparesis or hemiparesis has confirmed greater weakness in all muscles tested using age- matched controls (73). Weakness was more pronounced distally, as expected, and hip flexors and plantar flexors were relatively stronger than their antagonists when compared to the strength ratios of the control group. Strength of the uninvolved side in children with hemiparesis was also weaker than age-matched controls (73). Deficits in voluntary muscle contraction in CP are felt to be due to decreased central nervous system motor unit recruitment, increased antagonist coactivation, and changes in muscle morphology, including muscle fiber atrophy and increased fat and connective tissue (74). This weakness is thought to be a large contributor to functional deficits in children with CP, but historically, strengthening programs were not recommended due to concerns of increasing spasticity. A number of studies have shown, however, that strengthening programs can increase strength without adverse effects such as increased spasticity, resulting in an increased interest in strengthening programs for children with CP (75,76).
Although strengthening has the potential to positively affect children with CP in many areas of the International Classification of Functioning, Disability, and Health (ICF) model, most studies have focused on changes in strength alone. Recent studies have begun to evaluate changes in gross motor function related to increased strength. Improved gross motor function, as measured by the Gross Motor Function Measure (GMFM), has been reported following a 6- to 8-week program of strengthening (77-79).
Not all studies have demonstrated a positive effect with strengthening. An RCT evaluating the effects of a 9-month strength training program in addition to conventional physical therapy, versus therapy only following orthopedic surgery, did not demonstrate any improved function in the treatment group (80). Although not typically measured, increased participation and selfesteem have also been associated with participation in a strengthening program (81,82). Strengthening appears to be a promising intervention for children with CP, but future studies are needed to determine the effect of contextual and individual patient factors on a wide variety of potential outcomes, including societal participation.Partial Body Weight Support Treadmill Training (PBWSTT)
PBWSTT reduces the amount of weight required to support patients ambulating on a treadmill by utilizing a postural control system consisting of a harness. It has been effectively used in adults with diparesis and hemiparesis, and its use is gaining popularity in children with CP. Current theories of motor learning suggest that task-specific repetitive practice can improve activities, including walking, in people with neurologic disorders such as CP (83-85). The theoretical basis of this treatment is an activation of spinal and supraspinal pattern generators described in animal experiments with subsequent development of locomotion patterns (86). PBWSTT in nonambulatory subjects with cerebral palsy has demonstrated significant improvements in the standing and walking sections of the GMFM and functional gains, including the ability to transfer from a sitting to standing position without use of the arms, walking and stopping, and climbing stairs in some patients (87). An additional study, using a matched-pairs design, evaluated the effects of PBWSTT conducted twice weekly for six weeks in order to evaluate the walking speed and endurance of children with CP, with a GMFCS level of III or IV and revealed a significant increase in self-selected walking speed (83).
PBWSTT enabled by a driven gait orthosis (DGO) utilizes two mechanically driven leg orthoses, resulting in a kinematic pattern resembling normal walking.
This allows for an intensification of locomotor training by increasing the amount of stepping practice, as well as altering the amount of body weight support being provided while decreasing the therapist’s manual assistance. To date, few studies have reported on the effects of DGO in children. A study of 10 children with CP demonstrated a significant increase in gait speed, as well as markedly improved GMFM scores in Dimensions D (standing) and E (walking) following 10 to 13 sessions of using a DGO (88).Constraint-Induced Movement Therapy (CIMT)
CIMT was developed for treating adults with hemiparesis or “learned nonuse” following a stroke (89). The therapy includes intensive motor practice or shaping of the paretic upper extremity combined with restraint of the uninvolved extremity. CIMT is defined as restraint of the unaffected limb in conjunction with at least three hours per day of therapy for at least two consecutive weeks, whereas modified CIMT requires restraining the unaffected limb for fewer than three hours per day with therapy. Forced-use therapy involves restraining the unaffected limb with no additional therapy (90).
Children with hemiparetic CP have been described as having a “developmental disregard” for their impaired upper extremity (91). The favorable reports of CIMT in adults with stroke have resulted in an interest in applying the technique to children with hemiparetic CP. Preliminary results of controlled studies on a small number of subjects have revealed improved functional use of the affected extremity following CIMT (91), modified CIMT (92), and forced use (93,94). Cortical reorganization was also demonstrated by functional MRI and magnetoencephalography in case report of a child with hemiparetic CP following modified CIMT (95).
The preferred frequency, duration, or method of CIMT has yet to be determined. A variety of methods have been used to restrain the unaffected arm, including a long-arm bivalved cast, a short-arm cast, a sling, and a fabric glove with built-in stiff volar plastic
splint.
The child who is most likely to benefit from this therapy has also yet to be identified. In general, it is believed that the child must have the cognitive ability to understand and follow directions, the ability to at least grossly grasp and release an object, and have adequate balance to not be at substantial risk for falls when wearing the restraint (96). The ideal age for CIMT is unknown, but one study comparing CIMT in children ages 4 to 8 versus 9 to 13 years showed equal efficacy in either age group (97). Because the time involved in carrying through with a CIMT program can be difficult for parents and constraint of a child's good limb has the potential to lead to frustration on the part of the child, further carefully designed studies need to be undertaken to answer these important questions.Electrical Stimulation
Interest in the use of electrical stimulation in CP is growing. Proponents of electrical stimulation suggest that it increases strength and motor function, and it is an attractive alternative for strengthening in children with poor selective motor control (98).
Neuromuscular electrical stimulation (NMES). NMES utilizes electrical current to produce a visible muscle contraction. The results of two small case series found increased active and passive range of motion at the ankle after stimulation of the anterior tibialis (99) and improved sitting balance following stimulation of the abdominal and posterior back muscles (100). Two RCTs failed to identify any statistically significant improvement in strength or function following NMES of the quadriceps (101) or gluteus maximus (102), but both of these studies were underpowered.
Functional electrical stimulation (FES). If NMES is used to make a muscle contract during a functional activity, it is termed FES. FES is commonly used at the anterior tibialis muscle to increase dorsiflexion during ambulation. A small case series documented improvement in heel strike and ankle dorsiflexion following FES (103).
Another study identified clinically significant improvements in gait in only 3/8 subjects, as measured by a three-dimensional gait analysis (104). One proposed reason for lack of response was spasticity of the antagonist muscles limiting range and speed of movement.Threshold electrical stimulation (TES). TES is a low-level electrical stimulus, often applied during sleep, that does not result in a visible muscle contraction. The proposed mechanism of TES is that increasing blood flow during a time of heightened trophic hormone secretion results in increased muscle bulk (105). There have been four RCTs evaluating TES to date, and three of them failed to show any improvement in strength or function (101,106,107). The parents, however, reported a perceived positive effect of treatment in two of the studies (106,107), and a decreased impact on disability as measured by the Lifestyle Assessment Questionnaire was found in the third (101). In the only positive RCT, children with spastic diparesis with prior selective dorsal rhizotomy were found to have improved GMFM scores following TES, despite a lack of significant improvements in strength, range of motion (ROM), or tone (108).
A systematic review of electrical stimulation in CP concluded that the scarcity of well-controlled trials makes it difficult to support definitively or discard the use of this therapy (98). In addition, the authors concluded that the available literature appears to provide more evidence to support the use of NMES than TES. Further studies with more rigorous designs, longer follow-up, larger sample sizes of more homogenous subjects, and clarity in the reporting of stimulation parameters are recommended to clarify the age and type of patient most likely to benefit from this intervention (98).