Infant kicking notes and bibliography

Notes: Development of kicking Chen 2020

  • Spontaneous kicking of the legs is present in utero and during early infancy with or without external stimuli.
  • The trajectory of spontaneous kicking is marked by decreasing kicking rates with age, high variability and flexibility, and better joint coordination as purposeful movements begin to emerge.
  • Newborns kick with a primarily alternating pattern
  • Dominant unilateral kicking patterns emerge at one month.
  • Bilateral synchronous kicking patterns become more prominent after five months of age.
  • Preterm infants who demonstrate predominantly unilateral kicks at two months of age and predominantly alternate kicks at four months of age have been shown to start to walk later than infants with typical development.
  • In general, infants demonstrate tight intralimb coupling of the movements of the lower extremity as the ankle, knee, and hip joints flex and extend almost synchronously.
  • Hip-ankle joint movements start to disassociate by the second month of age, followed by disassociations of hip-knee and knee-ankle joints between four and six months of age.
  •  Tighter intralimb joint coupling (less mature) at two months of age is associated with a later attainment of walking.

“The mobile paradigm is designed to test learning and memory in infants.14 An infant’s leg is tethered to an overhead mobile, such that when the infant kicks, the mobile moves. As a result, the moving mobile provides conjugate visual and/or auditory reinforcement to the infant. With this reinforcement, infants are able to learn the association between their kicking and movement of the mobile by showing increased kicking frequency. Full-term healthy infants learn this paradigm in one day and remember it for one week.15, 16 Interestingly, infants also demonstrated the ability to change their inter- and intra-limb kicking coordination in fairly complex ways,6, 16, 17 such as kicking more with the tethered leg, or moving their legs with less hip-knee coupling and specifically choosing a range of motion to induce external feedback more efficiently during the mobile paradigm.” Chen 2020 See original article for references.

Chen, C. Y., Harrison, T., McNally, M., & Heathcock, J. C. (2020). Preliminary evidence of an association between spontaneous kicking and learning in infants between 3-4 months of age. Brazilian journal of physical therapy, S1413-3555(19)30751-8. Advance online publication. https://doi.org/10.1016/j.bjpt.2020.09.002

Harbourne, R. T., & Stergiou, N. (2009). Movement Variability and the Use of Nonlinear Tools: Principles to Guide Physical Therapist Practice. Physical Therapy, 89(3), 267–282. http://doi.org/10.2522/ptj.20080130

Smith, B. A., Vanderbilt, D. L., Applequist, B., & Kyvelidou, A. (2017). Sample Entropy Identifies Differences in Spontaneous Leg Movement Behavior between Infants with Typical Development and Infants at Risk of Developmental Delay. Technologies, 5(3), 55. http://doi.org/10.3390/technologies5030055

PROSSER, L. A., OHLRICH, L. B., CURATALO, L. A., ALTER, K. E., & DAMIANO, D. L. (2012). Feasibility and preliminary effectiveness of a novel mobility training intervention in infants and toddlers with cerebral palsy. Developmental Neurorehabilitation, 15(4), 259–266. http://doi.org/10.3109/17518423.2012.687782