Dozens of studies have been conducted on massage therapy effects on children and adolescents over the last few decades. Because these have not been reviewed in one place previously, they will be referenced here. The child and adolescent massage therapy studies have focused almost exclusively on problematic conditions including attention disorders, psychological problems, gastrointestinal problems, motor tone disorders, pain syndromes, autoimmune and immune conditions. Accordingly, these studies are grouped by these categories in the following summaries.
4.2. Psychological Problems
Psychological problems have also been the focus of pediatric massage therapy research including aggression, anxiety, depression, and posttraumatic stress disorder (PTSD). In a study on preschoolers “with aggressive and deviant behavior” 50 children were massaged daily for 20-min and compared to a group of 50 children who listened to stories [31
]. By the third month and again at 6 and 12 months, the massaged children had lower parent and teacher rated aggression scores on the Child Behavior Checklist. The children also had fewer social and somatic problems.
In a similar paradigm used by another group of researchers, three groups of second grade children including massage, storytelling and control groups were compared on their aggressive behavior and academic performance after ten fifty-minute sessions [32
]. In this case, both the massage and storytelling groups showed decreased aggressive behavior and improved academic performance, suggesting that giving children extra attention in itself helps reduce their aggression.
In an earlier study, aggressive adolescents who were residing on a closed hospital unit because of their aggressive behavior were given a month of 10-min daily chair massages [33
]. At the end of the month they were less aggressive. In a similar study on children and adolescents who were hospitalized for their anxiety and depression, those mood disorders were not only decreased but other measures of anxiety and depression including norepinephrine and cortisol were decreased following a month of 20-min daily massages [34
]. Hospitalization anxiety itself has been reduced in school-age children who received 20-min massages three times a day for three days [35
]. On the fifth day, their state anxiety as well as their heart rate and blood pressure were reduced.
Following Hurricane Andrew, children who had experienced the eye of the hurricane showed posttraumatic stress disorder symptoms [36
]. Following one month of daily massages, they had fewer PTSD symptoms including less depression, anxiety, and sleep disturbance. In addition, their self-drawings (a very reliable measure for children) were more colorful and more elaborate than at the beginning of the study.
Eating disorders including anorexia and bulimia might also be considered psychological disorders for their associated depression symptoms. Eating disorders have rarely been treated by massage therapy despite the notable decrease in depression following massage. In an early study on anorexia in adolescent girls, eating disorder symptoms and depression were decreased and excessively low-dopamine levels were increased following one month of daily 20-min massages [37
]. The same effects were noted for adolescent girls with bulimia following the same protocol in a separate study [38
]. These studies highlight the importance of assessing massage therapy effects on biochemical imbalances such as depressed dopamine levels as well as behavior and mood disturbances in children and adolescents with psychological problems.
4.4. Motor Tone Disorders
Two other contrasting disorders are cerebral palsy for its excessive motor tone (spasticity or hypertonicity) versus Down syndrome for its hypotonicity (flaccidity). Massage therapy has reduced both hypertonicity and hypotonicity.
In early studies on cerebral palsy, children’s hypertonicity was decreased after a month of daily bedtime massages by their parents [41
]. In a more recent study from Islamabad, Pakistan, children with cerebral palsy were given 30-min massages five times per week for six weeks [43
]. The children’s spasticity was significantly reduced by the end of the study. In a survey study on the prevalence of massage therapy for children and adolescents with cerebral palsy, 80% of the children had received massage while only 51% were currently receiving massage and 77% by their parents [44
Down syndrome infants with hypotonicity showed increased muscle tone following a month of 15-min daily massages by their mothers [45
]. In that study, motor scores and object manipulation scores improved in both the children with hypertonicity and hypotonicity following a 5-month massage therapy period [45
]. Improvement continued at a 6-month follow-up assessment even though massage therapy effects do not typically persist when the therapy is discontinued.
Children with motor development delays but with no cerebral palsy diagnosis have also benefited from massage therapy [46
]. In this study, children 1–3 years of age were randomly assigned to a control group or a massage group that received 20 min massages twice a week for 12 weeks. Unlike most other studies on children with motor development problems, these researchers stratified the children by age and motor development quotient, making this massage study more robust than most. The massage group showed greater improvement on gross motor and sensory sensitivity scores.
4.5. Painful Procedures and Pain Syndromes
Pediatric massage has reduced pain during painful procedures as well as for chronic pain conditions. Painful procedures have included hematopoietic cell transplantation and cardiovascular surgery. Burns and post burn pain have been the focus of several pediatric massage studies. Chronic pain in general and juvenile rheumatoid arthritis pain in particular have also been reduced by massage therapy.
In a study on hematopoietic cell transplantation, children received massages from both therapists and parents [47
]. The children reputedly experienced pain relief from the massage. In addition, they had less nausea and they had an easier time falling asleep. The parents also reported increased closeness to their children following massage. The parents preferred a semi-standardized massage protocol, highlighting the individual preferences for different massage techniques. Although the parents were requested to apply moderate pressure, there were no compliance checks on the parents’ massages in this study. In a study on pain and anxiety after cardiovascular surgery, sixty children were randomly assigned to receive three massage sessions or three reading visits on the first three postoperative days [48
]. The children receiving massage therapy had significantly lower anxiety scores and lower total benzodiazepine exposure for the three days following heart surgery.
In one of the first massage studies on young children with burns, the children’s pain thresholds were increased following 20-min massages as suggested by less distress and crying during their subsequent skin-brushing sessions [49
]. In a later study, children from the same burn unit were noted to have less post-burn pain and itching following 20-min massages [50
]. As would be expected, decreased crying in children with burns has been accompanied by a significant decrease in heart rate and respiration following massage [51
]. In addition, increased range of motion also occurred following massage in the children with burns [52
]. Further, burned adolescents have also experienced a reduction in pain and itching following massage [53
Several diseases that have been associated with significant pain that, in turn, has been reduced by massage therapy include juvenile rheumatoid arthritis, sickle cell disease, and chronic pain for no known etiology. This has resulted in pediatric pain clinics offering massage therapy for pain reduction. In a study on sickle cell disease, for example, the children experienced significantly lower levels of pain, anxiety, and depression following massage [54
]. In this study, parents gave their children daily 10-min massages. At the end of four weeks, the massaged children had lower levels of pain, anxiety, and depression. In a study on children with juvenile rheumatoid arthritis, parents also massaged their children on a daily basis before bedtime [55
]. In this case, pain reduction was reported not only by the parents and children but also by the children’s physicians.
Several potential mechanisms have been suggested for the relationship between massage and pain reduction. One of the early theories for the effectiveness of massage for alleviating pain is that touch receptors (neurons) are longer and more myelinated (more insulated) than pain receptors and they, therefore, can transmit a signal to the brain faster than pain receptors can. The touch message that is received before the pain message then “closes the gate” (a biochemical/electrical phenomenon), so that the pain message that is the slowest to reach the brain is not received. This is called the “gate theory” [56
]. The adult analog is rubbing a bumped “crazy bone”. In a study called “The Gate Theory of Pain Revisited”, a neurocomputational model was formulated that was consistent with the biological one in that pain signals to the brain were blocked when the same area that was “pained” was touched [57
]. Stimulation of pressure receptors results in increased vagal activity and serotonin levels (the body’s natural pain suppressor) [58
]. A related mechanism is based on the decrease in substance P (a substance known to cause pain) as a result of the decreased cortisol following massage therapy [59
]. Furthermore, moderate pressure massage has also been noted to increase oxytocin and decrease beta endorphin [60
4.6. Chronic Illnesses
Youth with different chronic illnesses have responded positively to pediatric massage. These include asthma, cystic fibrosis, diabetes, dermatitis, cancer, and HIV. In one of the earliest studies on children with asthma (4–14-year-olds), parents were requested to massage their child for 15 min prior to daily bedtime for four weeks [61
]. Based on spirometry on the first and last days of the study, all pulmonary measures improved including forced vital capacity (a 24% increase), forced expiratory volume at one minute (FEV1) (a 27% increase), and peak expiratory flow (a 30% increase) that were recorded every night. These positive effects might have been explained by a significant decrease in cortisol. In a more recent randomized controlled trial on asthma, parents were asked to provide a 20-min massage before bedtime every night for five weeks [62
]. At the end of the study, the massaged children as compared to the controls showed higher forced expiratory flow in the first second (FEV1) and a higher FEV1/FVC (forced vital capacity) ratio. Although the groups did not differ on peak expiratory flow, the authors considered FEV1 and FEV1/FVC as the key pulmonary functions, thus concluding that massage therapy significantly benefited these children. In another pediatric massage study on children with asthma, the mothers who massaged their children experienced a decrease in their anxiety levels, highlighting the positive effects for both the massager and the massaged [63
In a recent systematic review and meta-analysis, 14 randomized controlled studies on 1299 children with asthma were included in the data analysis [64
]. In all the studies, peak expiratory flow and FEV1 were significantly increased and decreases were noted in PAF (which produces bronchoconstriction) and prostaglandins (that trigger inflammation). Although the authors highlighted these improvements in pulmonary function, they also noted that the limited research designs led to a high risk for bias. Typically, authors of meta-analyses search the literature for randomized controlled studies that meet inclusion criteria for being selected, e.g., having sufficient power for data analysis. Then the authors assess risk for bias in five domains including selection bias (randomization), performance bias (blinding of treatment), detection bias (blinding of outcome assessment), attrition bias (incomplete outcome data), and reporting bias (selective reporting). If any of these occur, the meta-analysis is considered high risk for bias. Of course, there are difficulties in blinding massage therapy, so those studies are at least at high risk based on that domain.
Cystic fibrosis (a recessive genetic disorder) affects the lungs primarily, although it can also affect the digestive system. Like children with asthma, children with cystic fibrosis have responded positively to massage therapy [65
]. In that study on 20 children (5–12-years-old), a reading group was compared to a massage group with the parents either reading to their children or massaging their children for 20 min a night before bedtime for four weeks. Although peak airflow significantly increased, this study did not include primary measures of pulmonary function, and gastrointestinal problems such as abdominal pain were not measured. The authors of a review on several cystic fibrosis studies also reported positive effects of massage [66
In another chronic illness study, children with diabetes were massaged by their parents for 15 min before bedtime over a period of one month [67
]. By the end of the month, the children were showing greater compliance for insulin and food regulation, and their glucose levels had decreased significantly from a high of 159 to 118 within the normal range. In a more recent study, children with diabetes were randomly assigned to a control group or a massage group who received 50-min massages three times a week for three months [68
]. Again, the blood glucose levels were significantly lower in the massage group versus a control group by the end of the three-month period. Unfortunately, glycosylated hemoglobin was not measured in either of these studies, a confirmatory measure that might be used in a future study on children with diabetes.
Children with atopic dermatitis (eczema) were massaged as their parents applied medicinal ointment for 15 min a night at bedtime for one month [69
]. The control group received the medicinal ointment without massage. The skin condition of the massaged children significantly improved including less redness, lichenification (thickening of skin resulting from scratching), scaling, excoriation (abraded skin), and pruritis (itching).
Several massage therapy studies have been conducted with children with cancer. One of the earliest studies involved parents massaging children who had leukemia 15 min before bedtime on a daily basis for one month [70
]. The children who were massaged experienced a decrease in depression and an increase in white blood cells and neutrophils by the end of the study. Surprisingly, none of the studies since then have assessed immune function. In another study on children with cancer, massage was more effective than quiet time at reducing heart rate and anxiety in the children as well as in the parent [71
]. In still another study, children with cancer received 20-min massages daily for approximately four days if they were inpatients and once weekly for four weeks if they were outpatients [72
]. The massage group as opposed to a standard treatment control group showed a reduction in anxiety, muscle soreness, discomfort and respiratory rate. In a sample of children on a pediatric cancer ward, three 20-min massages were provided on alternate days over a one-week period [73
]. The only effects reported were a reduction in pain while walking and during physical activities. Pain and anxiety have also been reduced by massage therapy during bone marrow aspiration in children with cancer [74
]. As in most of these studies, pain was assessed on a visual analogue scale and anxiety by a state/trait anxiety scale.
Other measures that have been used to document massage therapy effects include chemotherapy-induced nausea and vomiting and sleep. Because antiemetics are not entirely effective and because of their side effects, massage therapy has been used to reduce chemotherapy-induced nausea and vomiting in pediatric cancer centers [75
]. In a randomized controlled clinical trial, 70 children and adolescents undergoing chemotherapy were randomly assigned to a massage group that received 20-min massages 24 h and 0.5 h before chemotherapy and 24 h after chemotherapy [75
]. The nausea and vomiting (both the incidence and severity) were significantly less for the massage group. In a sleep study, adolescents with cancer who were hospitalized for at least four consecutive nights were randomly assigned to either a massage or a waitlist control group [76
]. The massage group who received at least two massages showed increased nighttime and overall sleep as measured by actigraphy (activity watches), one of the most objective measures used in this literature.
In a systematic review on massage in children with cancer, the authors found seven articles that met inclusion criteria, although the authors of these studies used different massage techniques and reported on different symptoms [77
]. The reviewers concluded that massage decreased pain, nausea, stress, and anxiety. In addition, white blood cells and neutrophils increased, but these were only measured in one of the seven studies, i.e., the study already reported on leukemia [70