Effects of kinesiology taping in children with cerebral palsy: a systematic review

Introduction: Cerebral Palsy is a group of non-progressive movement and posture disorders. There are many rehabilitation methods for children and adolescents with these disorders. Kinesiology Taping(KT) is becoming a popular as an option of rehabilitation method for these children. Objective: The aim of this systematic review is to summarize evidence regarding the methods of Kinesiology Taping use in children and adolescents with Cerebral Palsy and its effects. Materials: A search of scientific papers in the databases Medline, Scielo and PEDro was conducted with no data or language restriction. For this search the keywords “Kinesio taping”, “Kinesiology Taping”, “Taping”, and “Bandages” combined with “Cerebral Palsy” were used. The search was conducted between May of 2015 and November of 2016. Results: Eleven studies were included in the review, six were randomized controlled clinical trials, four were quasi-experimental studies, and one was a case study. In general, the studies followed the guidelines proposed by the Kinesiology Taping creator; they used corrective techniques and muscle contraction facilitation/inhibition techniques. Results varied according to techniques used and outcomes chosen. Conclusion: There is strong to insufficient evidence of KT effects in motor function related outcomes. Stronger quality level studies are necessary to support use of KT in clinical practice.


Introduction
Cerebral Palsy (CP) is a group of non progressive disorders of movement and posture that result from injury to immature brain [1,2].CP can be classified as spastic, dyskinetic, ataxic, hypotonic, or mixed, based on clinical presentation and area or nervous system injury.CP covers a diverse spectrum of impairments, which affect primary reflexes and muscle tone, muscle strength, motor coordination, postural control, and acquisition of motor milestones [3].
The impairments caused by CP may affect children's lives in many ways.According to the International Classification of Functioning (ICF), functional manifestations of a health condition are classified in different domains: body functions and structures, activity, and participation [4].In conjunction with the impairments in body functions and structures typical of each type of CP, children often have difficulties in performing activities such as sitting, walking, going up and down stairs, using the bathroom, and dressing.These limitations may restrict the child's participation in school, sports, social, cultural, recreational contexts [5 -7).
There are many physical therapy intervention techniques for children with CP [8].Lately, Kinesiology Taping (KT) is becoming a popular treatment option [6].KT consists in using an elastic, anti-allergic taping which may be stretched 130 to 140% of its original length [9].The objectives applying KT are to facilitate or inhibit muscle contraction, stabilize joints, and promote postural alignment through stimulation of mechanoreceptors in the skin [6,9,10].The physiological mechanisms behind purported effects of KT are not well defined.According to KT proponents, stimulation of skin mechanoreceptors can influence motor unit to produce "facilitation" or "inhibition" of muscle contraction, depending on the tape direction and tension [11 -14].The stimulation produced by the taping may add to or augment the voluntary control and coordination of children and adolescents with CP [3,6,15].
Given the recently increased popularity of KT and the lack of systematization of its effects, the aim of this study is to review and summarize the techniques of KT application and their effects in children and adolescents with Cerebral Palsy.

Methods
A search of scientific publications on the databases Medline, Scielo, and PEDro was conducted without language or date restriction, between May of 2015 and November 25th of 2016.The keywords "kinesio taping", "kinesiology taping", "taping" and "bandages" combined with "cerebral palsy" were used.The search was conducted by one investigator that identified Fisioter Mov.2017;30(Suppl 1):S373-82 relevant candidate studies based on their title and abstract.Two other investigators conducted a second round of selection among candidate studies based on the inclusion/exclusion criteria.The final selection was decided by consensus between both investigators, using a third one in case of divergence.
No review protocols were found in the searched databases.The studies included in this review were clinical trials and case studies that investigated the effects of KT on motor function for children and adolescents with CP.Clinical trials and case studies in adults and children with neurological dysfunctions other than CP were excluded.Studies that did not investigate the effects of KT related with motor function outcomes were also excluded.
The data about the methods, participants, and results was extracted by one investigator and checked by a second investigator.Subsequently, trials were rated for quality using the Physiotherapy Evidence Database-PEDro scale (ranging from 0 to 10 points) [16].No meta-analysis was conducted due the heterogeneity of the studies.

Study Characteristics
A total of 108 studies were found on the databases.After applying the inclusion/exclusion criteria, a number of 11 studies were selected by the investigators.Details of the selection process are shown in the figure I in a PRISMA flow diagram [17].
The description of KT intervention used by the studies is detailed in the table 1. Table 2 lists the patient characteristics, measurement instruments, and outcomes.
Six of the eleven selected studies were randomized controlled trials (RCT).Four of these studies were graded 6/10 [18 -21], and two were graded in 5/10 [22,23] according to the PEDro scale.Four studies were quasi-experimental designs [24 -27], and one was a case study [28].All studies reported patient's age, which varied between 3 and 17 years old, and CP type.Spastic CP was the most frequent diagnostic group.Six studies classified the level of motor function of the patients with the the Gross Motor Function Classification System (GMFCS) [16,17,19,20,22,25].GMFCS levels vary from 1 to 5 based on the child's functional limitations and use of orthotics, with 1 corresponding to the higher motor function level and 5 to the lower [29].One third of the patients were classified at level I, one third at levels II and III, and one third at levels IV and V.No studies investigated the relation between KT effects and GMFCS levels.
The KT direction is believed to be important with regards to desired effects of muscle contraction facilitation or inhibition [10,30,31].KT application direction, however, was mentioned in six studies [20, 22 -26].When facilitation of muscle contraction for better movement performance is desired, the tape should be applied from the muscle origin to its insertion [30,31].Six studies used this method in order to facilitate thumb abduction and fingers extension [25], dorsiflexion and knee extension [24], digit extension [26], and trunk extension [20,22].To avoid excessive contraction of a muscle, the opposite direction of application (insertion to origin) is indicated [30,3].One study applied the KT over the erector spinae muscles with the objective of inhibit excessive trunk extension in children with hypertonic trunk [22].Some application techniques aim to correct joint position and segment posture, presumably via feedback from mechanoreceptors [31].Cutaneous stimulation from the tape would act as augmented sensorial information, allowing the children to actively correct their posture [9,31].Some of the reviewed studies reported this KT technique [18,19,23,25,26].Mazzone et al. [25] taped the upper extremity in a spiral pattern from the base of the thumb to the humerus, in order to favor wrist extension and forearm pronation.Kara et al. [18] taped the wrist in a "buttonhole" shape, in order to promote extension.Keklicek et al. [23] taped the wrist obliquely from the ventral to the dorsal aspect in order to promote extension.The application also intended to stabilize the trapezio-metacarpal joint by promoting abduction and extension of the thumb.Ghalwash et al. [19] taped posteriorly the knee joint, aiming to reduce knee hyperextension.Almeida et al. [26] intended to promote calcaneal eversion and ankle dorsiflexion.
KT tension is also argued to be essential to the success of the technique [9,10,31].Nevertheless, only two studies [22,24] reported this aspect of the application.When the KT is stretched, the tension in the taping varies according to original length deformation from "none", to "very light (0-15%), to light (25%), to moderate (50%), to severe (75%) to complete (100%) [31].For example, a 5 cm stretch in a 20 cm tape would correspond to light tension.Both studies used light tension in order to facilitate muscle contraction.
In spite of the purported connection between aspects of KT application (shape, direction and tension) and physiological effects (muscle contraction, muscle relaxation, postural change) there is very poor documentation for the fundamental tenets of the technique in children with CP.Of the eleven reviewed studies, only one used electromyography to investigate muscle activation but did not report appropriate comparisons before and after taping [26].Explanations for possible effects of KT on other aspects motor function is limited by the unavailability of scientific evidence supporting its basic principles.

The Effects of KT interventions on the ICF domains
Studies included in the review assessed outcomes at different levels of the ICF, including body functions and structures and activity performance.

Range of Motion
In four studies, one of which was an RTC [19], interventions intended to increase joint range of motion (ROM) [19, 26 -28].Two studies analyzed ROM in functional activities (gait, and reaching forward) [26,28].A significant increase in dorsiflexion was found during gait, after the taping was tape was applied for twelve weeks with corrective techniques distally in the leg, over the calcaneus, transverse plantar arch, and dorsum of the foot.No control group for comparison was available, however.An increase in shoulder flexion and elbow extension was found during reaching forward in a case study in which KT was applied for three weeks over the shoulder [28].Two other studies (including the RTC) measured the effects of KT on isolated knee and ankle ROM and found no significant effects [19,27].
Fisioter Mov.2017;30(Suppl 1):S373-82 Balance Costa et al. [24] aimed in to improve the static and dynamic balance in four children with CP with the application of facilitatory KT on the tibialis anterior and quadriceps.The taping was applied while the child performed the Time Up and Go (TUG) and Pediatric Balance Scale (PBS) tests.There were statically significant improvements in the dynamic activities of the PBS were observed after intervention, but conclusive support for this effect is limited by lack of a control group.

Gait
Almeida et al. [26] used the KT with intention of favoring eversion with dorsiflexion and correcting equinus during gait.An increase in dorsiflexion at heel strike was observed after three months of taping, but not immediately after application.Authors attribute the change in heel strike at three months to facilitation of tibialis anterior and inhibition of the triceps surae activity, but report comparisons of muscle electromyographic levels between assessments.Additionally, no control group was available to support attribution any effects to the taping intervention.

Gross Motor Function
Six studies analyzed the KT effect in gross motor function of children with CP [18,19,21,22,20,27] with only not being RCT [27] All studies analyzed the gross motor function using the Gross Motor Function Measure (GMFM).No statically significant changes in gross motor function after the KT interventions were seen in four of the RTCs [18 -20, 22].Only one RCT showed positive changes in gross motor function after taping obliquely the trunk of children, in order to improve sitting position and decrease the kyphotic angle [21].However, no overall gross motor function data was provided, only the GMFM sitting subset.Kara et al (18) included taping for the upper extremity in their twelve weeks intervention protocol, and detected a significant improvement in the gross motor sub-score of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP), which includes upper extremity activities, unlike the GMFM [32 -34].

Sitting and Sit to Stand
Two RTC (21,22) assessed the sitting posture using the Sitting Assessment Scale (SAS), and the sitting dimesion of GMFM.Simsek et al. [20,22] taped erector spinae muscles while Karabay et al. [21] taped the superior trapezius muscle; both in facilitation techniques.Authors suggest that the KT intervention can increase the muscle control in the sitting posture, but muscle contraction levels were not measured in the studies.
Costa et al. [24] wanted to assess the performance during the sitting to stand task.KT was applied to facilitate muscle contraction the lower extremity.There were statistically significant results in the Timed Up and Go (TUG) test.The quasi-experimental study showed better post intervention scores.According to the authors the positive results was due an increase of knee extension and ankle dorsiflexion ROM, measured by movement analysis software.

Upper Extremity Function
Three studies [23,25,28] one being an RTC [23] intended to improve upper extremity function with the KT intervention.One study detected statistically significant improvements in reaching and manipulation activities with the Melbourne Assessment after two periods of five months of KT to promote thumb abduction, wrist extension, forearm pronation and shoulder external rotation [25].Better fine manual dexterity in the adapted version for children of the Nine Hole Peg Test was detected immediately after taping to correct thumb adduction [23].A case study reported better kinematic parameters for reaching after fifteen days of KT applied to the upper extremity.Details of the rationale and objectives of the application technique, however, were not reported [28].

Functional Independence
Two RCT studies used the WeeFIM to assess functional independence after KT interventions [18,22].The WeeFIM contains domains of self care, sphincter control, transfers, locomotion, communication and cognition [35,36].Kara et al. [18] reported significant improvements in the self-care domain compared to the control group after twelve weeks of KT intervention, in order to improve gross motor function.The taping was applied over the upper extremity (scapula, forearm and wrist) and lower (hip, knee and ankle) extremity, using facilitation and corrective techniques.No statistic significant improvements were seen in functional independence in the study of Simsek et al. [22], comparing to the control group after twelve weeks of intervention.The study aimed to make changes in the sitting posture applying the taping over the trunk.

Discussion
This review aimed to summarize the current evidence of the effects of KT in children with CP.There was heterogeneity in the population studied, with varying GMFCS level, type of CP, and age.The studies available were of poor to moderate in general.The levels of evidence of the outcomes presented were classified basing on the PEDro Scale in five different levels: strong evidence, moderate evidence, limited evidence, indicative findings, and no or insufficient evidence [37,38].
There is strong evidence of positive effects of KT on the sitting position and moderate evidence of positive effects of KT on upper extremity function.There are insufficient evidences of the effects of KT on other outcomes related to motor function as gait pattern, gross motor function, balance and range of motion.
Despite the positive results founded in four RCT, two on upper extremity function, and two on sitting posture.None of these studies used sham tape as the control intervention.These effects therefore could be due to placebo effects of taping.The findings of this review are in general agreement with other systematic reviews [39 -41] which reported no substantial evidence for the treatment efficacy of KT.Most studies investigating the clinical effects of KT technique on children with CP (and other populations as well) are low quality and report unsubstantial results.Additionally, it is also necessary to consider the fact that the fundamental assumptions of KT, that is, it´s supposed effect on muscle activation levels usually do not get tested.

Conclusion
There is strong evidence of positive effects of KT on the sitting posture using facilitation techniques; and moderate evidence of positive KT effects of KT on upper extremity function through positioning techniques.However, most of the results of this review suggest insufficient evidence about the effects of KT in children and adolescents with Cerebral Palsy.Stronger quality level studies are necessary to support use of KT in clinical practice.

Table 2 -
Patient Characteristics, Outcome Measures, and Main Results