Date of Paper/Work


Type of Paper/Work

Research Project

Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

First Advisor

David D. Chapman


BACKGROUND AND PURPOSE: Infants with SB present with a known central nervous system lesion that often results in neurologic, orthopedic, and/or cognitive impairments. They usually learn to walk significantly later than typically developing (TD) infants. The delays they experience in learning to walk appear to be related to the fact that they move their legs and kick less often than infants who are TD. Only a small number of studies have reported strategies that therapists and parents may use to increase how often infants with SB move their legs and kick. The purpose of this study was to examine the impact conjugate reinforcement has on the frequency of leg movements (LMs) and kicks generated by infants with SB.

METHODS: The LMs of 7 infants with lumbar or sacral SB were videotaped while they were supine in 3 conditions: Baseline; Acquisition (tethered to a mobile); and Extinction. The infants’ LMs were video-taped for two minutes in each condition which enabled us to capture their spontaneous and goal-directed LMs and kicks. The video-tape of each infant’s LMs were then behavior coded via a frame by frame analysis to identify how often each baby moved his or her legs and kicked in each condition as well as how often they generated 9 types of kicks.

RESULTS: A significant correlation was observed between LMs and kicks (r= .976, p=0.00). These infants moved their tethered leg significantly more than their untethered leg (p=0.036). These infants generated more goal-directed LMs and kicks in the acquisition and extinction conditions; however, these differences only approached significance (p < .05). Single kicks and parallel kicks were the most common types of kicks generated in each condition.

CONCLUSION: The present results are consistent with the literature and suggest that increased kicks lead to stronger neural connections and increased strength, which ultimately leads to earlier onset of ambulation. Due to the significant correlation between LMs and kicks, increasing the frequency of LMs in infants may increase the amount of kicks. However, further research is needed. This study was limited by the small sample size and large standard deviations within group means.