Preterm children are at increased risk of motor impairments and these impairments often persist into adolescence [1
]. Evidence regarding the effect of physiotherapy to improve motor development in preterm infants is limited [2
]. Interventions designed for promoting development in these infants have been heterogeneous and studies reporting a significant impact of early intervention on motor development are sparse [2
]. Examining an approach in which the therapy is adapted to the individual premature infant's needs may contribute to knowledge about how to enhance motor development in these infants. To that end we designed a study on the effects of physiotherapy in infants born prematurely as well as on professional performance and parents experiences. The intervention is performed before the infant's reach term age.
The study, named "The Norwegian Physiotherapy Study in Preterm Infants" (NOPPI), consists of a pragmatic randomized controlled trial and a qualitative observational and interview study. The project provides a new approach to intensive physiotherapy consisting of several more elements than today's traditional approach. The intervention integrates key elements from the modified version of the Mother-Infant Transaction Program performed in a study by Kaaresen and colleagues [4
], as well as elements from interventions in other studies which have shown a positive effect on premature children's motor development [2
]. NOPPI explores the effects of individually customized physiotherapy on preterm infants before they reach term age as well as assess the physiotherapy performance and parental experiences of participating in carrying out the intervention in the neonatal intensive care unit (NICU). Outcomes are measured up to two years of age.
The theoretical framework related to the physiotherapy intervention in this study is knowledge of newborn behaviors [10
], the importance of parental competency [5
] and theories of motor development, including neuroscience and phenomenology of the body [13
]. A brief presentation of the framework follows.
Newborn behaviour and parental competency
Competency in behavioral organization makes active social participation possible for infants [10
]. As a group, however, prematurely born infants with very low birth weight, and particularly those with serious complications, are reported to have more difficulties in behavioral regulation than infants born at term [16
]. This may be expressed by the infant as irritability, requiring a long time to settle into a routine and fluctuating attention. Infants' neurobehavioral functioning unfolds through maturation and experience, and the individual can be helped to self-regulate by the caregiver and environmental adaptations. Parental competency to read and understand the individuality and needs of their infant is significant in decreasing parental stress [5
] and enhances cognitive outcome and social functioning in the infants [18
Phenomenology of the body
The body forms the base from which both the infant as a person and the world are constituted. A newborn's body is a tactile-kinesthetic body. Through moving, infants learn and experience movements by which kinesthetic competency develops [19
]. On the basis of innate spontaneous movements, the infant learns to know their own body as well as gaining knowledge and realization of the surroundings. Their bodies are both expressive and experienced at the same time. Thus, child development can be understood as a result of interaction among the system consisting of perception, sensation and movement.
Theory of motor development
The motor development of a child is non-linear [21
] and regarded as a product of both genetic processes and experiences [23
]. In dynamic systems theory [25
], motor development is believed to be a feedback process based on interaction among different subsystems in the child, the environment and the task. There is a shift from trial and error phases of instability to stable movement in which the synergy of appropriate movements is used to perform a functional task [23
]. The motor patterns of healthy children appear flexible, adaptable and dynamic [23
The motor patterns of preterm infants are dominated by extension and to a lesser degree flexion when compared to infants born at term [26
]. This fact, in addition to possible brain damage, may influence the children's spontaneous motor experiences and the process of developing stable motor strategies as they grow. Motor function is related to the development of postural control which is necessary to transfer and modify body weight distribution for appropriate functional movement, communication and social interaction [27
]. To have postural control is then about maintaining a bodily position over time, regaining postural stability after perturbations, managing changes between different postures, and integration of postures into locomotion and exploration [27
]. Interventions that optimize postural control and selective movement in preterm infants may therefore be important in reducing the degree of delayed motor development or the severity of cerebral palsy (CP).
The human brain in infancy is highly plastic and there is an active growth of dendrites and formation of synapses. Experience influences and models the brain and leads to structural changes [24
] in, e.g., the number of synapses that are developed, the synapses' position and functioning, as well as elimination of synapses that are not needed. Motor skills may be highly influenced by early intervention because the motor pathways forming the corticospinal tracts already show mature myelin at term age [30
] and myelination may be activity-dependent [31
There is some evidence that recovery from central nervous system injury in infants can be understood both by new growth of motor neurons and creation of new synapses. Moreover that part of the brain is not yet developed for specific tasks and may be developed for other uses than were originally intended [24
]. Of these insights about brain plasticity it is suggested that early-targeted customized individual intervention could be of great importance to the development of movement quality and function of preterm children.